The International Journal of Oral & Maxillofacial Implants, 05/2013

Tissue engineering is defined as the use of a combination of cells, engineering principles, and materials along with suitable biochemical and physicochemical factors to improve or replace biologic function. In practice, tissue engineering tends to be associated with repair or replacement of partial or whole tissues. The field originated as a component of biomaterials, but it has developed into a distinct entity. In the history of implant dentistry we can see many parallels with tissue engineering. The osseointegration process depends upon a biologic response to an alloplastic device that is used to replace teeth. The engineering principles are involved in the design of prostheses in such a way as to use the supporting implants to replace the tooth root while traditional prosthodontic procedures are performed to simulate the crown and surrounding soft tissue. Today the two fields are burgeoning, sometimes independent of each other and, in most instances, in collaboration. Indeed, this journal routinely provides scientific articles that incorporate elements from traditional implant dentistry and regenerative dental efforts. The growth in both fields appears to be rapidly expanding and it is unlikely that a plateau will be reached in the near future. Recognizing this, The International Journal of Oral and Maxillofacial Implants is initiating a "Tissue Engineering" section. This new section, edited by Dr Ole Jensen, will bring cutting-edge research to our readership. From scientific theory to translational research, our readers will benefit from the knowledge presented. I am sure you will find this new section intellectually stimulating. We have been fortunate to receive permission to include a number of articles related to tissue engineering that were previously published in Oral & Craniofacial Tissue Engineering. Beginning in this issue and continuing in the next three issues, the full text version of these articles will appear on the JOMI website and the abstracts in the print journal. These articles will provide the readers with a tremendous opportunity to see the compelling information available in the newest section of this journal. Beginning with this issue, JOMI also is changing the way that it recognizes reviewers. Before I explain the changes, I will describe the expectations that the journal has for its reviewers. We realize that the quality of article reviews dictates the quality of articles in the journal. Good reviewers provide constructive reviews, and when the reviews identify issues that should be addressed, the authors are able to incorporate those changes to make an article better. Sometimes the changes suggested by the peer review process relate to the need for better descriptions of the study design. Many reviews identify a need for enhanced statistical analysis. Graphics, in the form of figures, tables, or charts, may benefit greatly from the eye of a third party. Indeed there are many factors identified by reviewers that, once addressed in a revision, result in articles that are more clear, more precise, and easier to read. Understanding the vital role that the reviewers play, it seems appropriate to recognize their contributions in a more timely way. Previously reviewers were recognized annually through a published "thank you" that listed the names of all the reviewers for the previous year. We are now planning to list the names of the reviewers for the articles found in each section of the journal. This will provide a more immediate recognition and it also lets the readers and the authors know how much the reviewers contribute. We do recognize that some articles may never be published for one reason or another. The reviewers of such articles still provide a huge contribution and their efforts will continue to be recognized in the annual expression of gratitude for efforts of the reviewers. I look forward to these two new initiatives. Keeping the journal relevant, fresh, and educational remain the primary goals of the editorial staff.

Purpose: To evaluate the effects of bisphosphonates on bone healing after tooth extraction and osseointegration of dental implants in a rabbit model. Materials and Methods: Twenty-four rabbits were divided into four groups; one control and three experimental. The experimental were treated with intravenous zoledronic acid (ZA, 0.1 mg/kg) twice per week starting 4 (Z4 group) and 8 (Z8 group) weeks before surgery until the end of the experiments. The experimental ZD4 group was treated with intravenous ZA (0.01 mg/kg) and intramuscular dexamethasone (1 mg/kg) twice per week starting 4 weeks before surgery until the end of the experiments. The maxillary first premolar was extracted, and an implant with a diameter of 1.5 mm was placed between the incisor and the premolar of each maxilla. Healing of the extraction socket was evaluated and histomorphometric analysis around the implant was performed, using the bone-to-implant contact ratio (BIC) and bone area ratio (BA) 4 and 8 weeks after the surgery. Results: The control group underwent a normal healing process, but all experimental groups showed necrotic bone with hollow lacunae. BIC and BA in the control group increased from the 4- to 8-week evaluations, but decreased in the experimental groups from 4 to 8 weeks. BIC and BA of the Z8 and ZD4 groups were higher than those of the control group at the 4-week evaluation, but were lower than the control at the the 8-week evaluation. Conclusions: This study showed that administration of bisphosphonates interferes with normal bone remodeling after tooth extraction. The experimental groups showed good initial stability, but long-term healing around the implants was impaired. Within the limits of this study, it may be suggested that patients taking bisphosphonates should be treated with caution when performing tooth extraction or placing dental implants.

Purpose: The purpose of this study was to compare a newly designed trephine drill (SLA KIT, Neobiotech) with conventional rotary instruments for maxillary sinus floor elevation based on operative time, postoperative pain, and perforation rates. Materials and Methods: Twenty-five patients were treated with a bilateral sinus floor elevation procedure with rotary trephine and conventional instruments. One side was treated with conventional rotary instruments, while the contralateral side was treated with rotary trephine instruments, with a 2-week gap between surgeries. Operative time was measured with a chronometer in seconds as the time from soft tissue incision to primary closure of the incision with the last suture. Pain was scored on a 10-point visual analog scale at 24 hours after surgery. The presence of tears and perforations was determined by direct visualization and the Valsalva maneuver. Results: Twenty-five patients were included in the study. Operative time was shorter when the trephine drill was used (11.1 ± 2.4 minutes) than with conventional rotary instruments (15.1 ± 2.9 minutes). Sinus membrane perforation was observed in eight patients when conventional rotary instruments were used, while the trephine drill resulted in two sinus perforations. Mean pain scores were 2.01 ± 0.11 after using the trephine drill and 2.25 ± 0.76 when conventional rotary instruments were used. No significant difference was found in postoperative pain scores. Conclusion: The trephine drill technique may result in decreased perforation rates and operative time.

Purpose: To evaluate the marginal and internal adaptation of five-unit implant-supported fixed partial dentures with different superstructure and abutment materials with two different implant systems. Materials and Methods: Two mandibular epoxy resin models (one for each implant system) were fabricated, and implants were inserted in the canine, first premolar, and first molar regions. Thirty impressions of each model were then made. The 30 models of each group were divided into three subgroups: group 1, titanium abutment with metal (nickel-chromium) framework; group 2, titanium abutment with zirconium framework; and group 3, zirconium abutment with zirconium framework. The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, and the data were evaluated statistically using analysis of variance and the least significant difference post hoc test. Results: The highest values for internal adaptation were observed at the occlusal surface in all groups. There were statistically significant differences in marginal measurements between subgroups. The smallest gaps were found in group 1 (79.361 μm), and the largest gaps were found in group 3 (131.242 μm). Conclusions: In this study, marginal and internal gap measurements were 79 to 131 μm. The marginal discrepancy of the tested materials could be considered clinically acceptable.

Purpose: The purpose of this study was to systematically review the current evidence related to the effects of static loading on the long-term stability of the osseointegrated interface. Materials and Methods: The literature search was conducted using Medline supplemented by SCOPUS and the Cochrane databases as well as hand searching from references of reviewed papers. Relevant studies were selected according to predetermined inclusion and exclusion criteria. Key words used in the search included: dental implant passive fit, dental implant misfit, dental implant static load, dental implant overload, orthodontic forces, and dental implants. Results: The initial database search yielded 192 relevant titles. After the subsequent filtering process, 36 studies were finally selected. Twenty-eight articles involved animal studies and eight articles involved human studies. Conclusions: The results of this systematic review demonstrate that there is no apparent detrimental effect of static loading on osseointegrated dental implants.

Purpose: The aim of this study was to investigate the influence of oral implant surface roughness on bacterial biofilm formation and antimicrobial treatment efficacy. Materials and Methods: Titanium disks with low-roughness pickled surfaces and with moderately rough sandblasted, acid-etched surfaces were used as substrata. Streptococcus mutans biofilms (1 and 3 days old) and Porphyromonas gingivalis biofilms (3 days old) were grown on the two types of substrata and then treated with 0.2% chlorhexidine. Biofilm viability was evaluated by a resazurin metabolism assay and by sonication-colony-forming unit counts. Results: Surface roughness had no influence on the amount of biofilm formation by S mutans or P gingivalis in this in vitro biofilm model. However, it strongly affected the treatment efficacy of chlorhexidine on the biofilms formed by both species. Higher roughness resulted in lower efficacy. Furthermore, treatment efficacy was significantly reduced in older biofilms. Conclusion: A moderately roughened surface did not enhance biofilm formation but reduced treatment efficacy of the biofilms. This finding indicates that efforts should be directed toward optimizing implant surface properties for effective antimicrobial treatment without compromising osseointegration.

Purpose: Oral cancer therapy with surgery and radiation is associated with comorbidities; this affects rehabilitation with osseointegrated dental implants. The aim of this systematic review was to evaluate the effect of radiation therapy on osseointegrated dental implant survival in oral cancer patients. Materials and Methods: A review of the literature published between 1990 and June 2012 was conducted. Pertinent studies evaluating the effect of radiation therapy on osseointegration of implants were identified through searches of PubMed, SCIRUS, and Google Scholar. Overall implant survival rates were compared with respect to timing of radiation (prior to or after implantation), site of implant placement (maxilla, mandible, vascularized free flaps, nonvascular bone grafts), radiation dose, time interval between radiation therapy and implant placement, and the effect of hyperbaric oxygen therapy. Results: Thirty-eight articles were eligible for inclusion in the review. Overall implant survival rates with radiation therapy done pre- and postimplantation were 88.9% and 92.2%, respectively. In preimplantation radiation therapy, the implant survival rate was significantly higher for the mandible (93.3%) than for the maxilla (78.9%) or for grafted bone (87.5%). Similarly, the implant survival rate was higher when implants were placed in free flaps (89.3%) than in nonvascularized bone grafts (81.7%). While a radiation dose above 55 Gy significantly decreased implant survival, no significant relationship between increased implant survival and the remaining variables were found. Conclusion: There, was no significant difference in dental implant survival rates between preimplantation and postimplantation radiation therapy. The anatomical site of implant placement in preimplantation radiation therapy was the most pertinent variable affecting implant survival, with a better survival rate in the mandible compared to the maxilla and grafted bone.

Purpose: To evaluate factors that have an influence on histomorphometric bone-to-implant contact (BIC) of dental implants in humans. Materials and Methods: Using inclusion/exclusion criteria, eligible studies were searched in five databases and handsearched in 11 journals. A total of 351 articles were assigned to full text analysis. The extracted data were assigned to comparative statistical assessments and meta-analysis. Results: A total of 55 articles were included in the analysis. The mean BIC found in comparative assessments and meta-analysis of implants in the mandible (70.97 and 69.744 ± 3.304, respectively) was higher than those in the maxilla (53.24 and 56.692 ± 3.598; P = .000 and P = .008, respectively). The mean BIC in the anterior mandible (79.42) and maxilla (74.19) were higher than the posterior mandible (69.14) and maxilla (36.68) (P < .05). Differences were detected in BIC of commercially available implants and experimental micro-implants (P < .05). Comparative assessments and meta-analysis showed that conventionally loaded implants (75.70 and 75.786 ± 4.889, respectively) had higher BIC than unloaded (54.07 and 53.24 ± 4.971, respectively) and immediately loaded implants (58.53 and 68.831 ± 4.972; P = .000 and P = .004, respectively). Conclusions: Based upon a meta-analysis of the literature the following conclusions can be made: The BIC in the mandible is higher than the maxilla. The BIC is higher in the anterior than the posterior regions. The implant design coupled with the anatomical region affects the amount of BIC. Placement of experimental micro-implants with different surfaces in the posterior region always result in low and almost comparable BIC. The loading state and healing period seems to have an influence on BIC. Specific reporting guidelines are required to improve reporting of studies on human BIC.

Purpose: A novel diagnostic device (BoneProbe) for evaluating alveolar bone quality during dental implant surgery has recently been developed. The underlying measurement principle is based on a compressive test of bone, which may subsequently affect bone healing and osseointegration of dental implants. Materials and Methods: Six implant sites each were created in the rear left tibia of four sheep and used for bone quality testing with the BoneProbe, while empty osteotomies and implants placed without testing served as controls. Maximum insertion torque and primary implant stability (Osstell) were determined additionally. After 5 and 20 weeks, the animals were sacrificed followed by histomorphometric and microradiographic analysis quantifying bone implant contact (BIC) and bone mineral density (BMD) as parameters. Statistical analysis was conducted applying one-sample t tests, two-sample t tests and Pearson correlation coefficients (α = .05). Results: Implants placed following application of the BoneProbe differed from the control treatments only in one case, where BIC was greater (P = .02) at the control implant after 20 weeks of healing. With the exception of the combinations of Osstell/BoneProbe measurement in trabecular bone (0.29) and Osstell/insertion torque (0.34), good correlations of all clinically conducted measurements were found. Conclusion: Based on the results obtained, it appears that intraoperative testing of bone quality applying the BoneProbe does not jeopardize bone healing and osseointegration of dental implants.

Purpose: This is the first study to report the clinical outcomes of photofunctionalized dental implants. Materials and Methods: This retrospective study analyzed 95 consecutive patients who received 222 untreated implants and 70 patients who received 168 photofunctionalized implants over a follow-up period of 2.5 years. Photofunctionalization was performed by treating implants with UV light for 15 minutes using a photo device immediately before placement. The generation of superhydrophilicity and hemophilicity along with a substantial reduction in atomic percentage of surface carbon was confirmed after photofunctionalization. In both groups, 90% of the implants were placed in complex cases requiring staged or simultaneous site-development surgery. The implant stability was measured at implant placement and loading using the implant stability quotient (ISQ) values; then, the rate of implant stability development was evaluated by calculating the ISQ increase per month. Results: The healing time before functional loading was 3.2 months in photofunctionalized implants and 6.5 months in untreated implants. The success rate was 97.6% and 96.3% for photofunctionalized and untreated implants, respectively. The ISQ increase per month for photofunctionalized implants ranged from 2.0 to 8.7 depending on the ISQ at placement, and it was considerably higher than that of untreated implants reported in the literature ranging from -1.8 to 2.8. Photofunctionalization resulted in a more frequent use of implants of 10 mm or shorter length and an overall decrease in implant diameter. Conclusions: Within the limits of this retrospective study, despite the more frequent use of shorter and smaller-diameter implants, the use of photofunctionalization allowed for a faster loading protocol without compromising the success rate. The outcome was associated with an increased rate of implant stability development. The results suggest that photofunctionalization may provide a novel and practical avenue to further advance implant therapy.

Purpose: To evaluate the effect of surgical placement of an aminoguanidine (AG)-loaded chitosan membrane, which allows slow local release of AG, over an endosseous implant on mechanical retention of the implant in nondiabetic and diabetic rats. Materials and Methods: Forty-eight male Wistar rats were randomly divided into six groups of eight animals each and subjected to three different treatment modalities: (1) implant placement in the femur, (2) placement of implant + chitosan membrane without AG at the surgical site, or (3) placement of implant + AG-loaded chitosan membrane (AG concentration of 7.35 mmol/kg body weight) at the surgical site. Groups 1, 2, and 3 were nondiabetic (control groups), and groups 4, 5, and 6 had chemically induced type 1 diabetes (test groups). At 4 weeks after implant placement, the animals were sacrificed and the countertorque force (CTF) required to disrupt the bone-implant interface was measured. Analyses of variance were performed, and the mean CTF values were compared between groups by using the Student t test. Results: The mean CTF values were significantly lower in diabetic groups not treated with AG than in the corresponding nondiabetic animals that had received the same treatment modality. In groups that received AG locally, the mean CTF values were not statistically significantly different, regardless of diabetes status. Conclusions: Induced diabetes (type 1) negatively affected the CTF necessary for disrupting the bone-implant interface. Local availability of AG in diabetic animals led to an increase in the CTF values to the same level as that in nondiabetic animals.

Purpose: To test in a rat model whether quantitative percussion diagnostics provide reliable, reproducible indications of osseointegration. Materials and Methods: Titanium implants were placed in femurs of 36 Sprague-Dawley rats. Each animal was assigned to one of six groups defined by one of three time points (2, 4, or 8 weeks postplacement) and one of two treatments (matrix metalloproteinase [MMP] inhibitor GM6001 or control). Percussion testing was conducted three times per subject at implant placement and before sacrifice at one of the time points. For each time point, there was an experimental group that received daily intraperitoneal injections of GM6001, and a control group that received no MMP inhibitor. The percussion data consisted of loss coefficient (LC) values that characterize energy dissipation. Statistical analysis was performed on the LC values for the two animal groups using the paired Student t test to assess differences as a function of time, and the independent t test to compare mean LC for the study groups at sacrifice (α = .05). Histologic evaluation using the osteogenic CD40 protein marker was also performed. Results: A nearly significant difference in mean LC at the 2-week time point was observed between the two treatments with the GM6001 group having the higher value (P = .053). There was a greater difference between the mean LC values for the 4-week GM6001 and control groups (P = .001). The histologic evidence for subjects in these two groups confirmed reduction of osteogenesis at the implant interface after administration of the MMP inhibitor. Conclusions: Lower control LC values relative to the GM6001 therapeutic group were observed, consistent with the effect MMP inhibition has on matrix remodeling at the implant bone interface. This finding in conjunction with histologic observations confirms that osseointegration can be monitored using percussion diagnostics.

Purpose: This study evaluated the survival and success rates and marginal bone loss conditions of early loaded implants in the posterior maxilla and mandible of partially edentulous patients. Materials and Methods: Implants (n = 299) were placed in 105 patients at two research centers. Provisional fixed dental prostheses were provided to the patients between 1 week and 2 months after implant placement. The implants were classified into four groups according to the loading time (1 to 2, 2 to 4, 4 to 6, and 6 to 8 weeks). Periapical radiographs were taken via a parallel imaging technique, and the peri-implant marginal bone level was measured on the radiographic images. Results: Most implants were lost within 1 month, and one implant was removed at 36 days after loading. The cumulative survival rate of the implants was 97.0%. Implants loaded in the maxilla at 1 to 2 weeks after prosthesis insertion had significantly lower survival rates than any other group (P = .013). There were no significant differences in marginal bone levels among the implant groups classified according to loading time. Conclusions: Early loading is a safe and predictable procedure for implant-supported restoration of posterior partial edentulism. However, care must be taken in early loading within 2 weeks after maxillary implant insertion.

Purpose: The purpose of this study was to evaluate the incidence of the most common technical problems with implant-supported fixed partial dentures (FPDs) and to assess the survival and success rates (event-free survival) after 5 to 10 years of function. Materials and Methods: All of the implants evaluated in this study were from a single manufacturer (Institut Straumann). Follow-up examinations were scheduled 1 week after suprastructure placement, 6 months later, and annually thereafter. Prosthesis-based data on survival/failure rates and technical complications were analyzed. Results: In 95 partially edentulous patients, 231 Straumann implants were placed and restored with 177 implant-supported prostheses (125 single crowns, 18 splinted crowns on two adjacent implants, and 34 three-unit FPDs). One hundred thirty one solid abutments and 100 synOcta abutments were inserted. The survival rate of prostheses supported by implants was 97.7%. The prosthetic success rate (event-free survival) was 96.05%. After an observation period of 5 years, the cumulative incidence of screw loosening was 0%. Fracture of the veneering porcelain occurred in 3.95% of all restorations. Fractures of the superstructure framework were not observed. The overall incidence of complications after 5 years was highest for splinted crowns, which showed the lowest success rate (94.4%), followed by three-unit FPDs (96%) and single crowns (98.4%). Conclusions: Single-unit restorations or short-span FPDs supported by both synOcta and solid abutments on Straumann implants showed low rates of technical complications, the most common being fracture of the veneering porcelain.

Purpose: To evaluate postoperative pain after successful implant surgery and compare pain experienced using conventional flap and flapless techniques. Materials and Methods: Between January 2007 and September 2012, consecutive patients with bilateral partially edentulous maxillae or mandibles were included in the study. Patients were randomly allocated to receive implants with an atraumatic flapless procedure or with a conventional flap procedure in a split-mouth design in a two-stage surgery. This randomized blinded prospective clinical study considered each patient as one unit. The data were analyzed using the Mann-Whitney and chi-square tests. Results: One hundred eight implants were placed in 19 patients. Radiographic and clinical examination showed that all implants were successful. Postoperative pain was significantly more intense after surgery with the conventional flap technique than after surgery with the atraumatic flapless technique. Likewise, the inflammatory response was more intense with the flap technique. Conclusions: Postoperative pain depends on the surgical technique used and is less intense with a flapless technique.

Purpose: To clinically and radiographically evaluate the performance of loaded dental implants placed in vertically distracted fibular grafts after mandibular reconstruction, and to evaluate patient satisfaction with implant function and esthetics after oral rehabilitation. Materials and Methods: This retrospective study involved patients who received implants in vertically distracted fibular bone after mandibular reconstruction between February 2006 and January 2008. Clinical assessments were performed 6 months after loading and annually thereafter. Patient satisfaction was evaluated with respect to function, phonetics, facial contour esthetics, and oral hygiene practices. The data were evaluated statistically. Results: Thirty-seven dental implants were inserted in 12 patients (mean age, 42.9 ± 8.0 years). Three patients were completely edentulous and nine were partially edentulous. The low mean plaque score (< 20%) indicated a good level of oral hygiene during the mean follow-up period of 42.1 ± 4.1 months. Probing depths and modified Sulcus Bleeding Index increased slightly at follow-up, but there was no significant difference in either parameter at years 1 and 3. After 1 year, the average marginal bone loss was 0.8 ± 0.3 mm (range, 0.2 to 2.1 mm); this increased to 0.9 ± 0.4 mm (range, 0.5 to 2.4 mm) in year 3, which was not a significant difference. The cumulative survival rate was 100% and the cumulative success rate was 84.8%. Seven of the 12 patients were fully satisfied with the function and esthetics of the restoration. Conclusions: On the basis of the present study, implant placement in vertically distracted fibulae for mandibular reconstruction may be considered a predictable option in terms of mid- to long-term implant survival and success rates.

Purpose: The objective of this study was to compare implant survival and success rates, peri-implant parameters, and prosthodontic maintenance efforts for implant-supported telescopic crown overdentures and bar overdentures to restore maxillary edentulism. Materials and Methods: This retrospective clinical study involved patients with maxillary edentulism who were fitted with implant-supported overdentures from January 2004 to June 2007. During a 5- to 8-year follow-up period, the implant survival and success rates, biologic and mechanical complications, prosthodontic maintenance, and patient satisfaction were retrospectively analyzed. The data were evaluated statistically and P < .05 was considered to be statistically significant. Results: Forty-four patients with maxillary edentulism received implant-supported removable overdentures. Twenty-one patients chose telescopic crown overdentures and 23 patients chose bar overdentures. A total of 41 patients and 201 implants were available for follow-up. The implant survival and success rates, average bone resorption, and subjective patient satisfaction scores showed no difference between the telescopic crown and the bar overdenture group at follow-up. However, there were higher values for Plaque and Calculus Indexes in the bar group compared with the telescopic crown group, and these values showed a statistically significant difference annually from the 3-year follow-up (P < .05). Each year, the number of prosthodontics maintenance procedures per patient did not significantly differ between the telescopic crown (approximately 0.36 to 0.58) and bar groups (approximately 0.30 to 0.49) (P = .16). Conclusions: Although there were higher plaque and calculus levels in the bar group and more maintenance was required for the telescopic crown group, overdentures provided a healthy peri-implant structure for implants in both groups. Implant-supported telescopic crown or bar overdentures can provide a good treatment option for patients with edentulous maxillae.

Purpose: Using short implants poses a challenge in implant surgery. Implant surfaces have evolved, making it possible to improve the success of short implants substantially. However, there is still little information about the long-term predictability achieved with short, rough-surfaced implants. The objective of this study was to evaluate the long-term survival rate of 6-mm rough implants. Materials and Methods: A retrospective multicenter analysis of the survival of short 6-mm SLA-surfaced implants was conducted. A total of 230 implants placed in 159 patients were included. The follow-up time ranged between 1 and 6 years. Results: Seven of the 230 implants failed, which gives a cumulative survival rate of 96.4%. Two hundred and fourteen implants were placed in the mandible (93.1%), as opposed to 16 placed in the maxilla (6.9%). Five implants failed during the osseointegration period, and two failed after receiving the prosthetic load. No statistically significant differences were found (P < .44). Of the loaded implants, 209 were splinted to other implants, as opposed to 14 that were not. One implant failed in each group, resulting in a 99.5% for the splinted implants and 92.9% for the unsplinted implants. No statistically significant differences were found between the splinted and unsplinted groups (P < .12). Conclusions: The short implants used in this study displayed high longterm predictability when placed in the mandible and splinted. There is insufficient- information to extrapolate these results to the maxilla and non-splinted implants.

Purpose: To present a new technique for the rehabilitation of the severely atrophied mandible that avoids the need for advanced surgical reconstruction. Materials and Methods: Severe resorption in the posterior mandible was treated following a conservative approach. A novel drilling technique and vertical implant-guided bone regeneration were performed to insert extra-short implants for maximum use of the bone above the mandibular canal. A progressive loading protocol was followed for the prosthetic rehabilitation with screw-retained prostheses. During the follow-up period, surgical complications, prosthetic failures, marginal bone loss, and implant survival were monitored. Results: The described conservative approach was effective in patients with residual bone height above the mandibular canal that was often less than 6 mm. No signs of sensory disturbances or nerve injury were detected during the observation period. One hundred fourteen extra-short implants were inserted in 72 patients, with a mean follow-up period of 26 months after implant insertion. The implant survival rate was 98.2% (two implants failed). Proximal bone loss was limited to 1 mm, and detailed analysis of factors influencing bone loss indicated that the increase in implant diameter was associated with a tendency toward decreased bone loss. Prosthetic complications (eg, fracture or screw loosening) were not observed in this study. Conclusions: This minimally invasive approach contributed to successful oral rehabilitation of patients with severely atrophied posterior mandibles. The development of conservative approaches will decrease the risk of surgical morbidity, save money and time, and decrease the complexity of surgery.

Purpose: Although flapless computer-guided implant placement provides important benefits, deviations from the planned implant placement in the edentulous arch may pose significant risks. This study evaluated the reliability and accuracy of a flapless computer-guided surgical approach. Materials and Methods: Computer-generated preoperative implant planning was compared to actual placement by cone-beam computerized tomography (CBCT) scanning of patients before and after surgery. A well-fitting complete denture or optimized prosthetic tooth arrangement was used and converted to a radiographic template. Prior to scanning, esthetics and functional aspects were checked clinically. The implant positions were virtually determined by the implant planning software relative to the bone structure and prospective tooth position. After implant placement, new CBCT scans were obtained for each subject. Software was used to fuse the images of the planned and placed implants, and the locations and axes were compared. The normality of the data distribution was evaluated by the Kolmogorov-Smirnov test. Mean values were compared between groups based on the upper or lower jaws with the t test for independent samples. The level of significance was fixed at 5%. Results: Sixty-two implants were placed in edentulous arches with stereolithographic surgical guides in 14 patients. Damage due to implant placement was not observed in any critical anatomical structure. Compared to the planned implants, placed implants showed mean and standard deviation linear measurements at the cervical, middle, and apical implant portions of 2.17 (± 0.87), 2.32 (± 1.52), and 2.86 (± 2.17) mm, for the maxilla, and 1.42 (± 0.76), 1.42 (± 0.76), and 1.42 (± 0.76) mm, for the mandible, respectively. The angular deviations were 1.93 (± 0.17) and 1.85 (± 0.75) degrees for the maxilla and mandible, respectively. The linear deviation differed significantlybetween the upper and lower jaws, but the angular deviation did not. Conclusion: Flapless computer-guided surgery may be a viable treatment option for rehabilitating the edentulous arch.

Purpose: To compare the 2-year survival and peri-implant bone loss of implants with and without a fluoride modification under immediate loading conditions in completely edentulous mandibles. Materials and Methods: A total of 125 Osseospeed implants (test group) were placed in 25 patients requiring a fixed rehabilitation. Implants were loaded immediately (baseline) with a provisional screw-retained prosthesis. Implant survival and bone level changes were analyzed at 3, 12, and 24 months. Results were compared with the outcome of 25 previously treated patients with immediately loaded TiOblast implants using the same treatment protocol (control group). Results: Implant survival was 100% for both groups. After 3, 12, and 24 months, the mean bone loss for the control group was 0.60, 0.81, and 0.84 mm on the patient level and 0.60, 0.80, and 0.86 mm on the implant level. For the test group, a mean bone loss of 0.14, 0.11, and 0.11 mm was for the patient; and 0.14, 0.11, and 0.11 mm with the implant as statistical unit after 3, 12, and 24 months, respectively. No statistically significant differences were observed comparing peri-implant bone loss at 3 months with 12 and 24 months in both groups, but the control group showed more peri-implant bone loss compared with the test-group (P < .001). Moreover, the control group showed an increasing interquartile range over time, suggesting that not every implant is reaching steady-state bone levels. Conclusions: Immediate loading of implants placed in the completely edentulous mandible is a successful treatment option with high survival rates and limited bone loss after 2 years. However, initial crestal bone preservation significantly benefits from fluoride modification.

Purpose: To enhance the stability of titanium (Ti) implants using conditioned medium (CM) derived from rat bone marrow stromal cell (BMSC). Materials and Methods: BMSCs were isolated from rat femurs and grown in culture, and the culture medium was used as CM. The CM was immobilized on the surface of Ti implants with calcifying solution. The topology of the Ti implants after immobilization of CM was observed by scanning electron microscopy (SEM). The Ti-immobilized CM was analyzed by liquid chromatography with tandem mass spectrometry. The adhesiveness and the osteogenic differentiation of BMSCs grown on CM-coated discs were analyzed by reverse-transcription polymerase chain reaction. Ti implants with specimen-immobilized CM labeled with quantum dots (QDs) were placed into rat femurs. The localization of the CM was detected by in vivo imaging at 1, 7, 14, and 28 days after implantation. The removal torque test and histologic bone implant contact (BIC) were also analyzed. Results: Rat BMSC-CM was successfully immobilized on Ti implants. The immobilized CM contained about 2000 proteins, including collagen type I, bone sialoprotein, fibronectin, and vascular endothelial growth factor that are important in new bone formation. CM promoted cell adhesion and osteocalcin gene expression of rat BMSCs. The labeled CM remained associated with the Ti implant at 1, 7, 14, and 28 days postimplantation. The removal torque value and BIC of Ti implants with immobilized CM were higher than those of control implants on days 1, 7, and 14 after implantation. Conclusion: Immobilized CM components on the surface of Ti implants promoted integration into bone during an early stage.

Purpose: To estimate the efficacy of various bone grafting materials in the healing of 8-mm-diameter critical-size defects (CSD) in guinea pig calvaria. Methods: In this randomized trial study, critical-size defects were created in the calvaria of 36 guinea pigs 6 months of age. Animals were assigned into three groups and each received one of three experimental protocols. In protocol A, the right-side defect was filled with macroporous biphasic calcium phosphate (MBCP Gel) and the left side was left empty as a control. In protocol B, the right-side defect was filled with demineralized freeze-dried bone allograft (DFDBA) and the left side was filled with Stypro. In protocol C, the right-side defect was filled with Bio-Oss and the left side was filled with autogenous bone. The percentage of new bone formation was evaluated histomorphometrically after 8 weeks. Results: The mean bone formation was 68.19% for autogenous bone, 66.96% for MBCP Gel, 57.28% for Bio-Oss, 50.19% for DFDBA, 18.79% for Stypro, and 10.61% for the empty control. Except for the MBCP Gel and autogenous bone groups (P = .6), the differences between the other groups were statistically significant (P < .05). Conclusion: The results of this study indicated that all the testing materials had different capacities to produce new bone in CSD of guinea pig calvaria. MBCP Gel showed promising results in producing new bone proportionate to the autogenous bone graft group.

Purpose: To evaluate the capabilities of gelatin derivatives that incorporate phenolic hydroxyl groups (gelatin-Ph) as a delivery carrier with recombinant human platelet-derived growth factor-BB (rhPDGF-BB) for bone regeneration. Materials and Methods: The growth factor release profile from gelatin-Ph gel or atelocollagen was analyzed to evaluate the capability of gelatin-Ph as a carrier. The biocompatibility of gelatin-Ph (ie, the survival rates of the cells during gelation, and the morphology and proliferation of the cells) were investigated with rat bone marrow cells (RBMCs) in vitro. To evaluate the effect of the gelatin-Ph-rhPDGF-BB complex on bone formation, the complex was applied to bone defects in rat tibiae and undecalcified specimens were fabricated for histologic analysis. Results: Scarce amounts of rhPDGF-BB from gelatin-Ph gel were detected during 30 days, but the addition of protease induced the release of rhPDGF-BB on day 31. No differences were observed in the survival rates of RBMCs during gelation and in the morphology and proliferation of RBMCs on the gel sheet between groups. Histological analyses demonstrated that the complex enhanced bone formation and mineralization at 2 and 4 weeks. Conclusion: These results suggest that gelatin-Ph gel can be an ideal delivery carrier, and the localized delivery of rhPDGF-BB in gelatin-Ph can contribute to bone formation.

Purpose: To study the effects of different chemically modified titanium surfaces on the proliferation, differentiation, adhesion, and apoptosis of osteoblast-like SaOS-2 cells. Materials and Methods: In this work, six different titanium materials were tested and compared to each other: (1) glazed; (2) unglazed; (3) unglazed and alkali-etched; (4) unglazed, sandblasted, acid- and alkali-etched; (5) unglazed and coated with zirconium nitride; and (6) unglazed, sandblasted, and acid-etched. The production of alkaline phosphatase (ALP), tumor necrosis factor alpha (TNF-α), matrix metalloproteinase-2, and the expression of adhesion proteins (integrin α3β1, vinculin) were evaluated using ELISA. Finally, the apoptosis of cells was analyzed by flow cytometry. Results: The most significant differences were found for unglazed sandblasted acid- and alkali-etched titanium discs compared with unglazed titanium discs. The production of TNF-α was decreased after 24 hours, as was the production of ALP after 72 hours. In contrast, the expression of integrin α3β1 was increased after 6 hours. None of the titanium discs showed an apoptotic effect on cells. Conclusions: This study has shown that physical surface treatments (such as surface roughness) play a more important role than chemical modifications. Generally, chemical modifications such as acid- and alkali-etching can affect the wettability of titanium surfaces, making a surface hydrophilic or hydrophobic according to the modification. The cell attachment is better on hydrophilic surfaces, while hydrophilic surfaces may slightly decrease the expression of ALP activity.

Purpose: The aim of this study was to compare bone formation and tissue reactions around implants with a calcium phosphate (CaP)-coated machined surface (CPMS) and a CaP-coated rough surface (CPRS) at critical-sized circumferential ridge defects in dogs after 4 and 8 weeks. Materials and Methods: All mandibular premolars were extracted bilaterally from five male mongrel dogs. After 8 weeks, circumferential marginal defects (2 mm wide and 5 mm deep) were created unilaterally using a customized drill at sites of CPMS and CPRS implant insertion. Four weeks later, the contralateral side was prepared using the same protocol. The dogs were sacrificed 4 weeks later. Specimens were analyzed histologically and histomorphometrically. Results: Both CPMS and CPRS implants showed successful osseointegration in the apical bone area (without defects) regardless of the observation period (4 or 8 weeks). All circumferential defects were incompletely filled and osseointegration was limited at the apical area of the defect. In the unfilled defect area, collagen fibers were arranged perpendicular or oblique to the exposed implant surfaces, especially on CPRS implants. Conclusion: Within the limits of this study, CPMS and CPRS implants showed no statistically significant differences in osseointegration and bone regeneration in circumferential defects, along with the unique feature of collagen fibers arranged perpendicular or oblique to the exposed implant surfaces.

Purpose: The purpose of this study was to compare the stress and strain occurring in peri-implant bone and implants used to support maxillary overdentures. Three-dimensional finite element analysis (3D FEA) was used to compare one-piece zirconia and titanium implants. Materials and Methods: Two types of implants were simulated using a 3D FEA model: one-piece zirconia and titanium implants (diameter, 3.8 × 11.5 mm) with 2.25-mm diameter ball abutments. In each simulation four implants were placed bilaterally in the canine/premolar region of an edentulous maxillary model. Static loads were applied axially and 20 degrees buccolingually on the buccal slope of the lingual cusps of posterior teeth of the first quadrant. Von Mises stresses and equivalent strains generated in peri-implant bone and first principal stresses in the implants were calculated. Results: Comparable stress and strain values were shown in the peri-implant bone for both types of implants. The maximum equivalent strain produced in the peri-implant region was mostly within the range for bone augmentation. Under oblique loading, maximum von Mises stresses and equivalent strain were more evident at the neck of the most distal implant on the loaded side. Under axial load, the stress and strain were transferred to the peri-implant bone around the apex of the implant. Maximum tensile stresses that developed for either material were well below their fracture strength. The highest stresses were mainly located at the distobuccal region of the neck for the two implant materials under both loading conditions. Conclusions: From a biomechanical point of view, ceramic implants made from yttrium-stabilized tetragonal polycrystalline zirconia may be a potential alternative to conventional titanium implants for the support of overdentures. This is particularly relevant for a select group of patients with a proven allergy to titanium. Prospective clinical studies are still required to confirm these in vitro results. Different simulations presenting various cortical bone thicknesses and implant designs are required to provide a better understanding of the biomechanics of zirconia implants.

Purpose: To evaluate the torque stability of different UCLA retention screws of single implant-supported crowns submitted to mechanical cycling. Materials and Methods: Crowns fabricated from nickel-chromium-molybdenum alloy were attached to external-hexagon implants and grouped by the different retention screws used (n = 10): Ti, titanium screws (BRUNIHT, Biomet 3i); Au, gold-palladium screws with 24-carat gold coating (Gold-Tite, Biomet 3i); TiC, titanium alloy (Ti-6Al-4V) screw with diamondlike carbon coating (Neotorque, Neodent); and TiN, Ti-6Al-4V screw with aluminum-titanium-nitride coating (Ti-Tite, Conexão). Three initial removal torque (RT) values were obtained for each screw after torque insertion using an analog torque gauge. The final RT was measured after mechanical cycling (1 × 106 cycles at 2 Hz under 130 N). Data were submitted to analysis of variance and the Fischer test. Results: Statistically significant differences were observed between the initial RT in groups Ti and TiN, and between TiC and TiN. No statistically significant difference was seen between mean RT obtained before and after mechanical cycling, except for the Ti screws. All groups exhibited similar torque maintenance after mechanical cycling. Conclusion: Although no significant difference was observed among groups for the final percentage of torque maintenance, the final RT values of the coated screws were higher than those of the noncoated screws.

Purpose: To assess inter- and intraobserver variability in wireless resonance frequency analysis (RFA) stability measurements of palatal implants and to evaluate the influence of age, sex, time after implant insertion, and measurement direction on variability. Materials and Methods: Three observers conducted wireless RFA stability measurements of palatal implants from 16 patients. Measurements were taken in anteroposterior and laterolateral directions and were repeated after 1 hour. Results: Data showed a small interobserver variation (1.93) with intraobserver variation (1.77) as its largest component. Time after implantation showed a strong influence (P = .027) on the interobserver variation. Conclusions: The tested wireless RFA device can be considered a reliable instrument for measuring the stability of palatal implants. Multiple readings and observers could further improve measurement reliability.

Reconstruction of complex defects involving the maxilla or mandible often requires transfer of free vascularized tissue. In the conventional approach, a flap is transferred to provide vital tissue, and subsequent shaping and debulking are required. The authors present their experience with prefabrication of vascularized fibular flaps. Since 1999, 48 prefabricated flaps have been used to reconstruct 28 maxillary and 20 mandibular defects. The technique involves two surgical steps (prefabrication and flap transfer) and requires accurate planning, done with a solid model of the skull. Correct positioning of the prefabricated flap is accomplished by using the occlusion as a guide. Planning includes fabrication of a provisional prosthesis that is fixed to the flap with implants. Putting the prosthesis into occlusion determines the position of the flap.

Purpose: Classic tissue engineering consists of three components: scaffold, cells, and growth or differentiation factors. Currently, expensive bone morphogenetic proteins are the most common substance used for hard tissue regeneration. An alternative could be gamma-aminobutyric acid/lactam (GABA-lactam) analogs. Materials and Methods: The effects of gabapentin-lactam, cis- and trans-8-tertbutyl-GABA-pentinlactam (trans-TB-GBP-L), and phenyl-GABA-lactam were tested in this study on ovine mesenchymal stem cell (MSC) proliferation. MSCs were selected from bone marrow aspirate concentrate by plastic adherence and amplified. Aliquots of the cells were incubated in medium, with four different concentrations of the GABA-lactam analogs dissolved in dimethyl sulfoxide. Cells in medium with and without dimethyl sulfoxide served as controls. Cell proliferation was tested with a nonradioactive assay. Before and after GABA-lactam analog influence, the MSC character was evaluated by the ability of the cells to differentiate into osteoblasts, chondrocytes, and adipocytes. Results: Proliferation was significantly increased under the influence of the analogs, depending on their concentration. MSCs cultured in 1 nmol/L trans-TB-GBP-L showed the highest proliferation rate. The MSC character was not altered. Conclusions: GABA-lactam analogs could be suited to stimulate MSC proliferation for tissue engineering applications. Further in vivo studies are necessary to evaluate the possible clinical potential of GABA-lactam analogs for hard tissue regeneration.

Purpose: This study compared the histologic parameters and outcomes of two types of grafts in large vertical maxillary defects: a composite graft of recombinant human bone morphogenetic protein-2/acellular collagen sponge (rhBMP-2/ACS), crushed cancellous freeze-dried allogeneic bone (CCFDAB), and platelet-rich plasma (PRP); and size-matched 100% autogenous grafts. Materials and Methods: Twenty patients each were treated with a composite graft, which contained 1.05 mg rhBMP-2/ACS per two-tooth segment together with CCFDAB and PRP, or a 100% autogenous graft prior to implant placement. Grafting material was contained within a titanium mesh crib. Results: Two grafts in each group were lost as a result of early mesh exposure and infection. Three grafts in each group developed a late exposure of the mesh that did not affect bone regeneration. The remaining 18 autogenous grafts all regenerated sufficient bone for implant restoration (100%), and 17 of 18 (97.4%) of the composite grafts regenerated sufficient bone for implant restoration. The autogenous grafts included 54% ± 10% of new viable bone but also included residual nonviable graft particles. The composite grafts contained 59% ± 12% viable new bone and no remaining nonviable bone particles. The composite grafting technique resulted in less blood loss and shorter surgical time but greater and longer-lasting edema. The costs of both grafts were nearly equal. Conclusion: A composite graft of rhBMP-2/ACS-CCFDAB-PRP regenerates bone in large vertical ridge augmentations as predictably as 100% autogenous graft with less morbidity, equal cost, and more viable new bone formation without residual nonviable bone particles, but with more edema. This composite graft represents an in situ tissue engineering concept that is able to achieve results equivalent to autogenous grafts in large vertical ridge augmentations without donor bone harvesting.

Purpose: The aim of this study was to investigate whether estrogen deficiency interrupts bone healing around titanium implants and to evaluate whether bone healing around implants under a condition of estrogen deficiency is affected by variations in implant surface characteristics. Materials and Methods: Forty-eight female rats were divided into two groups: ovariectomized rats (OVX; n = 24) and sham-operated rats (SHAM; n = 24). Each group was further divided into two groups: a machine-polished implants group and a sandblasted implants group. One implant was placed into the left femur of each rat 84 days after OVX or sham surgery. After 28 or 56 days, the rats were killed, and nondecalcified sections were obtained. Bone-to-implant contact (BIC) and bone area (BA) around the implants were assessed for cortical and cancellous bone. Furthermore, bone density (BD) was evaluated in a 500-mm-wide zone of cancellous bone lateral to the implants. Results: At 28 and 56 days after implantation, no significant differences were found between the OVX and SHAM groups for BIC and BA in cortical bone. BIC, BA, and BD with cancellous bone were lower in the OVX group than in the SHAM group. However, BIC and BA tended to increase with the sandblasted implant surface. Conclusions: Estrogen deficiency affected bone healing and bone density around titanium implants, especially in cancellous bone, but the sandblasted surface has the possibility to improve osseointegration. However, the positive effect of this rough surface is limited at the implant surface.

A case report and description of a new technique for bone morphogenetic protein-2 augmentation of the maxilla are provided here. Horizontal maxillary atrophy was treated with a full-arch alveolar split osteotomy combined with sinus floor intrusion. The defect was grafted with bone morphogenetic protein-2 and demineralized freeze-dried bone allograft. Nine months later, a transgingival approach was used to place dental implants and a prefabricated provisional denture. The provisional was attached to several implants and retrofitted into place following gingival sculpting to create a tooth emergence effect. To date, this patient has been followed for 2.5 years with no implant losses or bone level changes. In addition, the gingival profile appeared to be stable.

This case report presents the clinical application and outcomes of the use of a combined approach to treat a patient with a severe alveolar defect. Recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier, along with autogenous bone graft, bovine bone mineral, platelet-rich plasma, and guided bone regeneration, were used simultaneous with nonsubmerged implant placement. At 1 year postsurgery, healthy peri-implant soft tissues and radiographically stable peri-implant crestal bone levels were observed along with locally increased radiographic bone density. In addition, a cone beam computed tomography (CBCT) scan demonstrated apparent supracrestal peri-implant bone augmentation with the appearance of normal alveolar ridge contours, including the facial bone wall.

Closure of a 1.5-cm oral antral fistula was done in combination with sinus floor and extraction socket grafting using recombinant human bone morphogenetic protein-2 within a collagen sponge matrix. The approach to the sinus was transalveolar, with elevation of the sinus membrane done through a molar extraction socket. Following graft placement, soft tissue repair was done with a buccal advancement flap. A dental implant was subsequently placed and restored. Peri-implant bone and implant stability were well maintained at the 1-year follow up examination.

Purpose: The objective of this pilot study was to histologically evaluate bone regeneration using a self-assembling peptide hydrogel scaffold with recombinant human bone morphogenetic protein-2 (rhBMP-2) in a rabbit calvaria model. Materials and Methods: Five adult New Zealand White rabbits were used for the study. Each received four titanium cylinders, which were placed into perforated slits made in the outer cortical bone of the calvaria. The cylinders were filled with the following test materials: (1) unfilled control; (2) rhBMP-2; (3) PuraMatrix (PM), a synthetic self-assembling peptide (RADA16-I) consisting of a 16-amino acid sequence and with a three-dimensional structure; and (4) PM/rhBMP-2. Each cylinder was covered with a titanium lid. After 8 weeks, the animals were sacrificed, and ground sections were obtained for histomorphometric analysis. Results: Histomorphometric analysis showed that regenerated tissue in the cylinder with PM/rhBMP-2 was significantly increased compared to the empty control. The mean area values of regenerated tissue in the cylinders were 35.80% ± 10.35% (control), 47.94% ± 5.65% (rhBMP-2), 48.94% ± 11.33% (PM), and 58.06% ± 14.84% (PM/rhBMP-2). The mean area values of newly formed bone in the cylinders were 9.39% ± 4.34% (control), 14.03% ± 2.25% (rhBMP-2), 13.99% ± 2.15% (PM), and 16.61% ± 3.79% (PM/rhBMP-2). Neither rhBMP-2 nor PM alone significantly enhanced bone regeneration compared to the empty control cylinder. Conclusions: PM with rhBMP-2 significantly enhanced bone regeneration on the bone augmentation model in a rabbit. PM promises to be a useful alternative synthetic material as a carrier for rhBMP-2 for bone regeneration.

Purpose: The purpose of this article was to compare the yields of stromal multipotent stem cells (CD34+ and CD105+) and hematopoetic multipotent stem cells (CD44+) obtained from different areas via bone marrow aspiration (BMA). Materials and Methods: Sixty 60-mL bone marrow aspirates were taken from the tibial plateau, the anterior ilium, and the posterior ilium using a single point-of-care BMA technique and a single BMA concentration (BMAC) device. A 1-mL portion of each sample was used to determine CD stem cell concentrations and the nucleated cell count. The remaining BMA was centrifuged to separate the more mature red blood cell precursors from the stem cells and then concentrate the latter into a BMAC. The BMAC yield of 10 mL was analyzed with flow cytometry and nucleated cell counts to derive a concentration factor for the BMAC. Results: The yield of total nucleated cells was equal between the anterior and posterior ilium and more than twice that obtained from the tibial plateau. The CD44+ and CD105+ cell yields were also nearly equal between the anterior and posterior ilium but more than twice that of the tibial plateau; however, the ratios between the three different stem cell types in BMAC obtained from the different areas suggest varying potentials for tissue development. Conclusions: The ilium is the preferred donor site for obtaining autologous stem cells at the point of care. The tibial plateau yielded only half as much bone marrow multipotent/progenitor stem cells as did the anterior and posterior ilium. The composition of the BMAC from each site suggests that the potential for differentiation into various cell types changes depending on the source of bone marrow, but that BMAC represents 6.5 ± 1.0 concentration factor from BMA.

Purpose: The primary objective of this study was to evaluate the safety of a tissue-engineered human ex vivo-produced oral mucosa equivalent (EVPOME) in intraoral grafting procedures. The secondary objective was to assess the efficacy of the grafted EVPOME in producing a keratinized mucosal surface epithelium. Materials and Methods: Five patients who met the inclusion criteria of having one mucogingival defect or a lack of keratinized gingiva on a nonmolar tooth, along with radiographic evidence of sufficient interdental bone height, were recruited as subjects to increase the width of keratinized gingiva at the defect site. A punch biopsy specimen of the hard palate was taken to acquire oral keratinocytes, which were expanded, seeded, and cultured on an acellular dermal matrix for fabrication of an EVPOME. EVPOME grafts were applied directly over an intact periosteal bed and secured in place. At baseline (biopsy specimen retrieval) and at 7, 14, 30, 90, and 180 days postsurgery, Plaque Index and Gingival Index were recorded for each subject. In addition, probing depths, keratinized gingival width, and keratinized gingival thickness were recorded at baseline, 30, 90, and 180 days. Results: No complications or adverse reactions to EVPOME were observed in any subjects during the study. The mean gain in keratinized gingival width was 3 mm (range, 3 to 4 mm). The mean gain in keratinized gingival thickness was 1 mm (range, 1 to 2 mm). No significant changes in probing depths were observed. Conclusion: Based on these findings, it can be concluded that EVPOME is safe for intraoral use and has the ability to augment keratinized tissue around teeth. Future clinical trials are needed to further explore this potential.

The modified osteo-odonto keratoprosthesis (MOOKP) is a biologic keratoprosthesis that is used to treat a severely scarred cornea. The procedure involves multiple stages, including the transplantation of buccal mucosa to the damaged ocular surface and the implantation of an osteo-odonto lamina with a mounted polymethylmethacrylate lens. Among the keratoprostheses currently available, the MOOKP has proven to be the most effective based on the number of patients who have undergone the procedure and the duration of documented follow-up. Upon successful biointegration of the osteo-odonto lamina, the keratoprosthesis is able to resist resorption, provide stability, and prevent bacterial invasion and epithelial ingrowth. The effectiveness of the MOOKP is dependent on the anatomic and physiologic characteristics of the dental tissues and periodontal ligament.

Purpose: Following initial positive reports of the use of bone marrow aspirate concentrate (BMAC) in combination with bovine bone mineral (BBM) in augmentation procedures, the technique was evaluated in patients with mandibular deficiency. Materials and Methods: Two adult patients required surgical correction of a deficient alveolar ridge (one patient showed horizontal deficiency only, and the other patient presented with horizontal and vertical deficiency) prior to dental implant placement. In both patients, the reconstruction was performed with BBM in combination with mononuclear cells concentrated by the BMAC method using different techniques. Results: The patients recovered well from all surgical procedures. Histologically, there was uniform bone formation, which allowed placement of dental implants. Conclusion: The results suggest that the use of BMAC in combination with BBM, without autogenous bone, has the potential to restore horizontal and vertical mandibular alveolar defects, providing a functional bone structure and allowing dental implant placement for subsequent prosthetic rehabilitation.

Purpose: To study the changes in treatment outcomes of complete dentures and magnet-retained, implant-supported overdentures in a group of elderly patients. Materials and Methods: In this nonrandomized trial, 43 edentulous patients (14 men and 29 women) were fitted with complete dentures followed by implant-supported mandibular overdenture in a sequential model. Treatment outcomes used for analysis included objective assessment of denture quality (Woelfel's index), patient satisfaction, nutritional status, body mass index (BMI), and serum albumin level. The McNemar test was used to determine if significant differences in the Woelfel's index and nutritional status existed at different treatment phases. Repeated measures ANOVA and multiple pairwise comparison tests were used to analyze patient satisfaction. BMI status and serum albumin level at different treatment phases were analyzed with one-way ANOVA and Tukey post hoc test. Results: At the 1-year follow-up, significant improvements were recorded for the objective assessment of denture quality and patient complaints (P < .05). No subject was found to be malnourished at pretreatment and in subsequent treatment phases. BMI and serum albumin level were not significantly different at different treatment phases (P > .05) Conclusions: The present study demonstrated that in elderly patients with stable health and nutritional status, complete dentures made in a university clinic brought about overall improvement in denture quality and reduction in denture complaint score. Insertion of mandibular implant-supported overdentures further improved the mandibular denture quality and reduced the mandibular denture complaint score. In this group of patients, no improvement in BMI, serum albumin value, and nutritional status were documented.