PubMed ID (PMID): 27458617Pages 267, Language: EnglishEckert, Steven E.DOI: 10.11607/jomi.2016.2.tar, PubMed ID (PMID): 27458618Pages 273-277, Language: EnglishStanford, ClarkDOI: 10.11607/jomi.4188, PubMed ID (PMID): 26478970Pages 280-287, Language: EnglishBornstein, Michael M. / Seiffert, Carol / Maestre-Ferrín, Laura / Fodich, Ivo / Jacobs, Reinhilde / Buser, Daniel / Arx, Thomas vonPurpose: To evaluate the frequency, morphology, and locations of maxillary sinus septa using cone beam computed tomographic (CBCT) imaging of the entire maxillary sinus and to analyze factors influencing the presence or absence of septa.
Materials and Methods: CBCT images of the maxilla taken during a 1-year study period (October 1, 2012, to September 30, 2013) were evaluated for the presence and type of septa as well as the health or pathology of the maxillary sinus. Differences in age, gender, type of dentition, septa location, and sinus pathology with regard to the incidence of sinus septa were analyzed statistically.
Results: The study included 294 maxillary sinuses in 212 patients (126 women and 86 men) with a mean age of 53.8 years. Sinus septa were present in 141 patients (66.5%) and in 166 of 294 sinuses (56.5%). The most common orientation of the septa was coronal (61.8%), 7.6% were oriented axially, and 3.6% were aligned sagittally. Most septa were located on the floor of the maxillary sinus (58.6%), commonly (60.7%) in the region of the first and second molars. The maxillary sinuses were diagnosed in 36.4% of cases as healthy and without thickening of the sinus membrane. Sex was a significant variable in the health of the maxillary sinus; 57.7% of the sinuses in women and 72.3% in men were diagnosed as pathologic.
Conclusion: Septa are common anatomical structures and are most often found in the first or second molar region on the floor of the maxillary sinus. To prevent possible complications during sinus floor elevation procedures, a thorough three-dimensional radiographic examination of the sinus prior to surgery is recommended.
Keywords: cone beam computed tomography, interobserver reliability, maxillary sinus, maxillary sinus pathology, maxillary sinus septa
DOI: 10.11607/jomi.4265, PubMed ID (PMID): 27004275Pages 288-292, Language: EnglishMonje, Alberto / Galindo-Moreno, Pablo / Tözüm, Tolga Fikret / Amo, Fernando Suárez-López del / Wang, Hom-LayAlthough some systemic conditions have been associated with peri-implant disease, local contributing factors largely remain to be determined. This study aimed at evaluating, based on clinical photographs obtained from peri-implantitis treatment publications, the possible local contributing factors involved in its development based upon a survey obtained from three experienced clinicians (> 20 years of expertise). Cohen's kappa index was used to test the interexaminer reliability. "Too-buccal implant position" was the only parameter to reach almost perfect interexaminer agreement (κ = 0.81). "Thin-tissue biotype" and "minimal presence of keratinized mucosa" demonstrated moderate agreement (κ = 0.43 and κ = 0.58, respectively). The rest of the parameters studied based on clinical photographs were fair or poor. Therefore, based on this clinicians' survey, implants too buccally placed, minimal or a lack of keratinized mucosa, and thin-tissue biotype might contribute to a higher susceptibility of developing peri-implantitis. These factors must be the focus of attention in future cross-sectional studies on the incidence of peri-implant diseases.
Keywords: endosseous implants, evidence-based, implantology, osseointegration, peri-implantitis, risk factor
DOI: 10.11607/jomi.4531, PubMed ID (PMID): 27004276Pages 294-303, Language: EnglishPripatnanont, Prisana / Praserttham, Pongsakorn / Suttapreyasri, Srisurang / Leepong, Narit / Monmaturapoj, NarupornPurpose: This study aimed to evaluate the effect of biphasic calcium phosphate (BCP) with high hydroxyapatite/tricalcium phosphate (HA/TCP) ratios on bone formation in rabbit calvarial defects.
Materials and Methods: Sixteen New Zealand white rabbits were randomly divided into two groups, a control group and an experimental group. In each animal, bilateral circular defects (10-mm diameter) were created on the calvarium. In the control group (three rabbits per time frame), defects were grafted with autogenous bone chips in one side and left empty in the other side. In the experimental group (five rabbits per time frame), defects were grafted with BCP1 (HA:TCP, 8:2) in one side and BCP2 (HA:TCP, 9:1) in the contralateral side. The animals were sacrificed at 2 and 8 weeks as designated. Bone formation and residual grafting material were assessed by radiographic densitometry, microcomputed tomography (micro-CT), and histomorphometric analysis.
Results: Histologic observation revealed that BCP1, BCP2, and the autogenous bone group preserved good contours of the defect, while the unfilled defect group showed connective tissue healing. Micro-CT analysis at 8 weeks showed the comparable percentages of bone volume fraction (% BV/TV) of BCP1 (20.70% ± 2.76%) and BCP2 (20.72% ± 3.97%) and two times higher than that of 2 weeks (9.90% ± 0.75%, 10.57% ± 0.85%). The autogenous group had a significantly (P .005) greater % BV/TV (34.58% ± 8.85%) than other groups. The percentage of the material volume fraction of BCP1 and BCP2 was not different. The histomorphometry demonstrated a higher increase in newly formed bone from 2 to 8 weeks in all groups, and all were comparable (autogenous: 4.30% ± 0.76%, 12.83% ± 7.74%; unfilled: 2.82% ± 1.19%, 8.14% ± 6.35%; BCP1: 3.01% ± 2.57%, 8.81% ± 3.86%; BCP2: 3.24% ± 1.09%, 10.27% ± 3.98%).
Conclusion: BCP with a high ratio of HA presented good osteoconductive properties and space-maintaining capacity and would be beneficial for long-term preservation or when stable graft volume is essential.
Keywords: biphasic calcium phosphate, histomorphometry, micro-CT, nanohydroxyapatite, rabbit
DOI: 10.11607/jomi.4601, PubMed ID (PMID): 27004277Pages 304-309, Language: EnglishWeyhrauch, Michael / Igiel, Christopher / Scheller, Herbert / Weibrich, Gernot / Lehmann, Karl MartinPurpose: The fracture strengths of all-ceramic crowns cemented on titanium implant abutments may vary depending on crown materials and luting agents. The purpose of this study was to examine differences in fracture strength among crowns cemented on implant abutments using crowns made of seven different monolithic ceramic materials and five different luting agents.
Materials and Methods: In total, 525 crowns (75 each of Vita Mark II, feldspathic ceramic [FSC]; Ivoclar Empress CAD, leucite-reinforced glass ceramic [LrGC]; Ivoclar e.max CAD, lithium disilicate [LiDS]; Vita Suprinity, presintered zirconia-reinforced lithium silicate ceramic [PSZirLS]; Vita Enamic, polymer-reinforced fine-structure feldspathic ceramic [PolyFSP], Lava Ultimate; resin nanoceramic [ResNC], Celtra Duo; fully crystallized zirconia-reinforced lithium silicate [FcZirLS]) were milled using a CAD/CAM system. The inner surfaces of the crowns were etched and silanized. Titanium implant abutments were fixed on implant analogs, and airborne-particle abrasion was used on their exterior specific adhesion surfaces (Al2O3, 50 μm). Then, the abutments were degreased and silanized. The crowns were cemented on the implant abutments using five luting agents (Multilink Implant, Variolink II, RelyX Unicem, GC FujiCEM, Panavia 2.0). After thermocycling for 5,000 cycles (5 to 55°C, 30 seconds dwell time), the crowns were subjected to fracture strength testing under static load using a universal testing machine. Statistical analyses were performed using analysis of variance (α = .0002) and the Bonferroni correction.
Results: No significant difference among the luting agents was found using the different allceramic materials. Ceramic materials LiDS, PSZirLS, PolyFSP, and ResNC showed significantly higher fracture strength values compared with FSC, FcZirLS, and LrGC. The PSZirLS especially showed significantly better results.
Conclusion: Within the limitations of this study, fracture strength was not differentially affected by the various luting agents. However, the fracture strength was significantly higher for PSZirLS, PolyFSP, ResNC, and LiDS ceramics than for the FSP, LrGC, and the FcZirLS ceramic with all luting agents tested.
Keywords: CAD/CAM, cement, ceramic, fracture strength, implant, luting agents
DOI: 10.11607/jomi.4681, PubMed ID (PMID): 27004278Pages 310-317, Language: EnglishTran, Duong T. / Gay, Isabel C. / Diaz-Rodriguez, Janice / Parthasarathy, Kavitha / Weltman, Robin / Friedman, LawrencePurpose: To compare dental implant survival rates when placed in native bone and grafted sites. Additionally, risk factors associated with dental implant loss were identified. This study was based on the hypothesis that bone grafting has no effect on implant survival rates.
Materials and Methods: A retrospective chart review was conducted for patients receiving dental implants at the University of Texas, School of Dentistry from 1985 to 2012. Exclusion criteria included patients with genetic diseases, radiation and chemotherapy, or an age less than 18 years. To avoid misclassification bias, implants were excluded if bone grafts were only done at the same time of placement. Data on age, sex, tobacco use, diabetes, osteoporosis, anatomical location of the implant, implant length and width, bone graft, and professional maintenance were collected for analysis.
Results: A total of 1,222 patients with 2,729 implants were included. The cumulative survival rates at 5 and 10 years were 92% and 87% for implants placed in native bone and 90% and 79% for implants placed in grafted bone, respectively. The results from multivariate analysis (Cox regression) indicated no significant difference in survival between the two groups; having maintenance therapy after implant placement reduced the failure rate by 80% (P .001), and using tobacco increased the failure rate by 2.6-fold (P = .001).
Conclusion: There was no difference in the dental implant survival rate when implants were placed in native bone or bone-grafted sites. Smoking and lack of professional maintenance were significantly related to increased implant loss.
Keywords: dental implant, retrospective study, risk factors, survival rate
DOI: 10.11607/jomi.4234, PubMed ID (PMID): 27004279Pages 318-323, Language: EnglishYou, Dae-Jong / Yoon, Hyun-JoongPurpose: The purpose of this study was to histomorphometrically compare the effects of the bilayer bone augmentation technique for the treatment of dehiscence-type defects around implants and evaluate the role as a membrane of the xenogeneic bone positioned as the outer layer in the bilayer bone augmentation technique.
Materials and Methods: Four standardized dehiscence defects measuring 5 mm in height from the crestal bone, 3 mm in width mesiodistally, and 4 mm in depth from the surface of the buccal bone were prepared on each mandible unilaterally in three dogs, and one implant was placed per defect, where each defect was treated with autograft, xenograft, the bilayer bone augmentation technique, or negative control without a membrane. The animals were sacrificed after an 8-week healing interval for histomorphometric analyses. The measurements of newly formed bone height, newly formed bone height contacting the implant, newly formed bone area, and the width of newly formed bone were made using incandescent and polarized light microscopy.
Results: Bone height and newly formed bone height contacting the implant in the autograft group were higher than in the xenograft, bilayer bone augmentation, and control groups. Newly formed bone area in the bilayer bone augmentation and autograft groups was higher than in the xenograft and control groups. The width of newly formed bone at 4.5 mm apically from the implant shoulder was greater in the xenograft and bilayer bone augmentation groups than in the control and autograft groups. However, the differences between the groups in bone height, newly formed bone height contacting the implant, newly formed bone area, and width of newly formed bone were not statistically significant in the histomorphometric examinations (P .05). Data were verified with the Kruskal-Wallis test.
Conclusion: The results of this study show the osteogenic effect of autogenous bone and the effect of mechanical support for prolonged space maintenance of xenogeneic bone for the treatment of dehiscence-type defects around implants. Further studies with a larger sample size are needed to confirm the efficacy of the bilayer bone augmentation technique.
Keywords: bilayer bone augmentation, dehiscence defect, dental implant
DOI: 10.11607/jomi.3900, PubMed ID (PMID): 27004280Pages 324-330, Language: EnglishGherlone, Enrico / Capparé, Paolo / Vinci, Raffale / Ferrini, Francesco / Gastaldi, Giorgio / Crespi, RobertoPurpose: This study aimed to evaluate the most accurate impression technique for "All on Four" restoration, comparing conventional (CIG) and digital impressions (DIG).
Materials and Methods: Patients randomly selected for this study were required to be edentulous in at least one arch, presenting with severe posterior mandibular or maxillary atrophy. All patients underwent full-arch immediate-load rehabilitations, which were fixed to a total of four implants (two axial and two tilted). Following implant placement, patients were stratified into two groups. Conventional pick-up was carried out in the control group, and digital impressions were performed in the test group. Following prosthetic rehabilitation, patients underwent intraoral digital radiographs to check for the presence of voids at the bar-implant connection and to evaluate accuracy. Three-, 6-, and 12-month follow-up examinations were performed.
Results: A total of 25 patients received immediately loaded "All-on-Four" prostheses (17 maxillary, 13 mandibular) supported by four implants (total 120 implants), of which five received both maxillary and mandibular prosthetic rehabilitation (three patients in CIG, two patients in DIG). No implant dropouts occurred, showing a survival rate of 100%. The digital impression procedure required significantly less time than the conventional procedure (P .001).
Conclusion: Results demonstrate that it is possible to develop computer-aided design/computer-assisted manufacturing (CAD/CAM) cobalt-chromium full-arch rehabilitations with satisfactory accuracy using digital impression techniques.
Keywords: digital impression, immediately loaded implants, tilted implants
DOI: 10.11607/jomi.4108, PubMed ID (PMID): 26478975Pages 331-337, Language: EnglishMakary, Christian / Rebaudi, Alberto / Menhall, Abdallah / Naaman, NadaPurpose: To radiographically monitor sinus membrane swelling after lateral sinus floor elevation surgery at short and long healing periods.
Materials and Methods: For 26 patients seeking posterior maxillary implant-supported reconstruction, 32 lateral sinus floor elevations were performed using Piezosurgery. Sinus membranes were grafted using synthetic calcium phosphate bone substitutes, and graft volume was measured in cubic centimeters for each case. Cone beam computed tomography (CBCT) examination was conducted preoperatively in all patients and for each grafted sinus at 1 day (n = 8), 2 days (n = 9), 3 days (n = 8), or 7 days (n = 7) after surgery. Control CBCT was then performed for all patients at 3, 6, and 12 months after surgery. Sinus membrane thickness was measured on cross-sectional CBCT images at nine standardized points per sinus, before lateral sinus floor elevation and at all postoperative examinations.
Results: Mean sinus membrane thickness was 0.73 mm before surgery, and 5 mm, 4.1 mm, 5.9 mm, and 7 mm, respectively, at 1, 2, 3, and 7 days after surgery. First week combined postoperative CBCT measurements of membrane thickness was 5.4 mm, then 1.3, 0.68, and 0.39 mm at 3, 6, and 12 months, respectively, after surgery. Membrane thickness significantly increased the first week after surgery and gradually decreased significantly at 3, 6, and 12 months in all groups (P .001). First-week postoperative measurements showed a significant increase in membrane thickness at 3 days compared with the 1- and 2-day results (P .001) and at 7 days compared with all other time points (P .001). Membrane thickness at 2 days did not change significantly compared with 1-day measurements. Larger graft volume was positively correlated with an increase in membrane thickness after surgery at all time points (n = 32; r = 0.527; P .001).
Conclusion: After lateral sinus floor elevation surgery, transient swelling of sinus membrane is observed. It reaches a peak value 7 days after surgery and completely resolves over months. This swelling is correlated to the extent of sinus floor elevation.
Keywords: CBCT, lateral sinus floor elevation, mucosal thickness, posterior maxilla, sinus augmentation, sinus membrane
DOI: 10.11607/jomi.INSERT4DIGITDOI, PubMed ID (PMID): 26478967Pages 338-351, Language: EnglishAtieh, Momen A. / Duncan, Warwick J. / Faggion jr., Clovis M.Purpose: During the last two decades, many clinical trials and systematic reviews (SRs) have evaluated the clinical outcomes of immediate implant placement and its effects on soft and hard tissue. Despite the increased popularity and knowledge of immediate implant placement, the evidence about its benefits is still not conclusive. The aim of this review was to assess the quality of published SRs with meta-analyses of immediate implant placement and provide an overview of the key findings.
Materials and Methods: Searches of MEDLINE, EMBASE, the Cochrane Library, and the Database of Abstracts of Reviews of Effects were performed to include SRs with meta-analysis of immediate implant placement. Two independent reviewers assessed the methodologic quality of SRs using A MeaSurement tool to Assess Reviews (AMSTAR), the 2003 checklist of Glenny et al, and the Critical Appraisal Skills Program (CASP).
Results: A total of 742 articles were found; 5 were included. All included SRs were published after 2007. Implant survival rate was the most commonly reported outcome. There was insufficient information in the primary studies, and hence in the SRs, about other outcomes and any adverse events. However, the methodologic quality of the SRs was considered to be high.
Conclusion: There is a general consensus among the included SRs that it is still premature to draw definite conclusions about the potential benefits of immediate implant placement because of the limited number of well-designed controlled clinical trials. Improvements in future SRs are still required and can be achieved by following established quality criteria, namely researching the unpublished literature and literature not in English and by reporting the quality assessment of primary studies and any sources of bias.
Keywords: dental implants, evidence-based dentistry, evidence-based practice, meta-analysis, review
DOI: 10.11607/jomi.4111, PubMed ID (PMID): 27004281Pages 352-358, Language: EnglishSoardi, Carlo Maria / Amo, Fernando Suárez-López del / Galindo-Moreno, Pablo / Catena, Andrés / Zaffe, Davide / Wang, Hom-LayPurpose: The aim of this study was to analyze cone beam computed tomography (CBCT) densitometries of maxillary sinuses augmented with human bone allograft. In addition, previously obtained microradiographic specimens were used to verify the diagnostic potential of CBCT.
Materials and Methods: A two-stage protocol was conducted in 21 consecutive patients, all with a crestal bone height 2 mm. Mineralized human bone allograft particles were used to augment sinuses using a lateral window approach. A succession of CBCT scans of the maxilla were taken before surgery, immediately after sinus augmentation, and 6, 10, and 18 months after implant placement. Using virtual probes, CBCT images taken at 6, 8, and 10 mm from the crestal surface were processed with medical imaging software and expressed as gray level (GL).
Results: A total of 24 sinus augmentation procedures were performed in 21 patients. The average values of CBCT-GL ranged from 571 to 654, presenting the maximum value at 8 mm immediately after implant placement and the minimum value at 6 mm after 10 months. Furthermore, it was found that the graft mineral content decreased over time, completely disappearing between 10 and 11 months.
Conclusion: CBCT and the medical imaging software employed for imaging visualization are reliable tools to study biomaterial behavior after sinus augmentation procedures. In addition, results from this study demonstrate that a complete resorption of human bone allograft is possible. Due to the limited sample size, further clinical and morphometric studies are needed.
Keywords: bone allograft, cone beam computed tomography, maxillary sinus augmentation, microradiographs
DOI: 10.11607/jomi.4150, PubMed ID (PMID): 26478978Pages 359-368, Language: EnglishRakic, Mia / Grusovin, Maria Gabriella / Canullo, LuigiPurpose: To qualitatively investigate the microbiologic profile in peri-implantitis by systematically reviewing the published literature on peri-implant infection.
Materials and Methods: Searches of the US National Institutes of Health free digital archives of the biomedical and life sciences journal literature (PubMed) and The Cochrane Library of the Cochrane Collaboration (CENTRAL), as well as a hand search of other literature, were conducted to identify articles potentially relevant for the review. Randomized clinical trials, prospective cohort studies, longitudinal studies, case-control studies, and cross-sectional studies in humans reporting microbiologic findings in patients with diagnosed peri-implantitis were considered eligible for this review. Screening, data extraction, and quality assessment were conducted independently and in duplicate.
Results: Twenty-one articles were eligible for inclusion in this review. Early studies focused on the identification of target periopathogens, whereas more recent studies used advanced molecular techniques for comprehensive overview of the peri-implantitis-associated microbiome. In summary, the microbiologic profile in peri-implantitis (1) is complex and variable, (2) consists of gram-negative anaerobic periopathogens and opportunistic microorganisms in almost the same ratio, (3) is frequently associated with the Epstein-Barr virus and nonsaccharolytic anaerobic gram-positive rods, (4) is not so strictly associated with Staphylococcus aureus, and (5) is different from that of periodontitis. A meta-analysis could not be performed because of the heterogeneity of the reviewed studies.
Conclusion: Although a comparison of the published results was limited because of the inhomogeneity of the studies, it is clear that the microbiologic profile of peri-implantitis consists of aggressive and resistant microorganisms and is distinct from that of periodontitis. It seems that the quantitative characteristics of the microflora cohabitants represent the key determinant of disease, rather than the qualitative composition, which is very similar in healthy and peri-implantitis states.
Keywords: bacteria, microbiota, peri-implantitis, periodontitis
DOI: 10.11607/jomi.4331, PubMed ID (PMID): 27004282Pages 369-375, Language: EnglishKarl, Matthias / Taylor, Thomas D.Purpose: Passive fit of implant-supported restorations is difficult to achieve. The aim of this randomized clinical trial was to test the null hypotheses that a reduction in misfit strain does not occur over time, regardless of the initial strain level, and that changes in prosthesis-induced bone strain do not differ between restorations with two different levels of fit.
Materials and Methods: Twenty edentulous sites were restored with screw-retained fixed restorations on two implants either cast in one piece (misfit) or assembled by an intraoral bonding procedure (fit). The restorations had a bar-shaped pontic onto which a strain-gauged metal plate could be fixed. Repeated strain gauge measurements on patient-specific in vitro resin models and on the implants intraorally were performed every 4 weeks for a period of 6 months. Statistical analysis was based on Kruskal-Wallis tests, t tests, Welch two-sample t test (α = .05), and linear regression analysis.
Results: No reduction in misfit strain could be observed in vitro, indicating that alterations in prosthetic fit had not occurred in any restoration (Kruskal-Wallis; P > .05). Initial strain levels varied widely and differed significantly between fit and misfit restorations (t test; P = .0032). Regrouping the restorations with respect to a threshold strain level of 100 μm/m resulted in 10 fit and 9 misfit restorations; 1 restoration had to be excluded from analysis due to a malfunctioning strain gauge. Seven fit restorations and five misfit restorations showed strain reduction in vivo based on linear regression, while percentage strain reduction did not differ between groups (Welch two-sample t test; P = .8186).
Conclusion: Within the limitations of this randomized clinical trial characterized by an observation period of 6 months and only healthy subjects being enrolled, bone adaptation around statically and dynamically loaded implants occurred, causing a decrease in misfit strain evoked by non-passively fitting prostheses. For maintaining osseointegration of dental implants, passivity of fit of multiunit restorations seems not to be as critical as previously thought.
Keywords: bone adaptation, misfit stress, passive fit, randomized clinical trial, strain gauge
DOI: 10.11607/jomi.4191, PubMed ID (PMID): 27004283Pages 376-381, Language: EnglishPark, Sun-Young / Oh, Sung-Hee / Kim, Jimin / Jung, Yea Ji / Park, Joo-Yeon / Lee, Eui-Kyung / Kim, Seong-Kyun / Kim, YounheePurpose: Many studies have investigated the impact of prosthetic treatment on oral health-related quality of life (OHRQoL). However, most of these have been performed among fully or partially edentulous patients. Studies involving patients with a single missing tooth are limited. The purpose of this study was to compare the OHRQoL between patients treated by single-tooth implants and three-unit fixed partial dentures (FPDs) for single missing tooth restoration.
Materials and Methods: A cross-sectional survey was conducted in Korea with patients drawn by stratified purposive sampling based on age. OHRQoL was measured using the Korean version of the 14-item Oral Health Impact Profile (OHIP-14K) questionnaire. Pre- and posttreatment OHIP-14K scores were compared by paired t test. Single-tooth implants and three-unit FPDs were compared by two-sample t test. In addition, multiple regression analysis was used to evaluate the impact of treatment mode on OHIP-14K total score after adjusting the effect of demographics and clinical factors.
Results: Thirty-five patients with single-tooth implants and 36 patients with three-unit FPDs were included. All participants had a significant improvement in OHRQoL compared with before the treatment (P .0001). However, there was no statistically significant difference in the change of OHIP-14K score between the two treatment modes. In addition, the treatment mode had no significant impact on the change of OHIP-14K total score after adjusting the influence of covariates (P = .170).
Conclusion: Both single-tooth implants and three-unit FPDs for single missing tooth replacement resulted in significant and similar improvement of OHRQoL.
Keywords: OHIP-14, oral health impact profile, oral health-related quality of life, single missing tooth, single-tooth implant, three-unit fixed partial denture
DOI: 10.11607/jomi.4189, PubMed ID (PMID): 27004284Pages 382-390, Language: EnglishHsu, Yung-Ting / Chan, Hsun-Liang / Rudek, Ivan / Bashutski, Jill / Oh, Won-Suk / Wang, Hom-Lay / Oh, Tae-JuPurpose: The aim of this study was to evaluate and compare the clinical and radiographic outcomes of single implants with a platform-switched rough collar (PSRC) and a platform-matched smooth collar (PMSC).
Materials and Methods: Twenty-six patients missing a tooth in the anterior maxilla (through the premolars) were randomly assigned to the PSRC or the PMSC group. All implants were placed in a flapless approach and restored with an early loading protocol. Clinical measurements were performed at surgery, loading, and at 3, 6, and 12 months after loading. In addition, radiographic evaluations were carried out using standardized periapical radiographs and cone beam computed tomography. Patient satisfaction surveys were completed, and microbial analysis with DNA probes was performed.
Results: The implant survival rate was 100% for both groups. The mean marginal bone level (MBL) was significantly higher in the PSRC group compared to the PMSC group at all time points. From the 2-week postoperative visit to 1 year postloading, the mean MBL change in the PSRC group was 0.21 ± 0.56 mm and in the PMSC group it was 0.74 ± 0.47 mm. Soft tissue profiles were stable over time, with no significant differences between groups. There were no significant differences between groups in the number of microbial species seen. Patients in both groups were highly satisfied with postoperative and postprosthetic experiences.
Conclusion: In this study, the PSRC method preserved marginal bone by a mean of 0.53 mm more than the standard PMSC protocol. Within the limitations of the present study, it can be concluded that the PSRC protocol may be beneficial in marginal bone preservation. Longitudinal studies are needed to verify the long-term effects of this approach.
Keywords: dental implants, esthetics, flapless surgery, microbiota, platform switching, rough collar, smooth collar
DOI: 10.11607/jomi.4251, PubMed ID (PMID): 27004285Pages 392-397, Language: EnglishThöne-Mühling, Miriam / Kelm, Daniela / Mengel, ReinerPurpose: The aim of this cohort study was to evaluate the width of keratinized mucosa at implant sites of partially edentulous patients who were treated for generalized aggressive periodontitis.
Materials and Methods: Dental implants were placed in 35 patients who were treated for generalized aggressive periodontitis and 18 periodontally healthy individuals (controls). At baseline, the keratinized mucosa of all implants was ≥ 2 mm. Follow-up examinations were conducted every 3 months over a 4-year period.
Results: The implant survival rate was 97.3% in patients with generalized aggressive periodontitis and 100% in the control group. Four years after implant insertion, patients with generalized aggressive periodontitis had significantly higher clinical attachment levels at the teeth and implants compared with the controls. At all time points, in both groups the mean probing depth at the implants was significantly larger than at the teeth. The mean widths of keratinized mucosa and keratinized gingiva were not significantly different between the two groups. In both groups, the widths of keratinized mucosa and keratinized gingiva were significantly higher at the maxilla than at the mandible. Four years after baseline, the implants in the mandible showed the smallest keratinized mucosa (mean: ≤ 1 mm).
Conclusion: During the first 4 years after implant placement, no significant changes in the keratinized mucosa at implants could be shown, either in periodontally healthy patients or in patients treated for generalized aggressive periodontitis. The keratinized gingiva at the teeth was generally significantly wider than the keratinized mucosa at the implants.
Keywords: aggressive periodontitis, dental implants, keratinized mucosa
DOI: 10.11607/jomi.4245, PubMed ID (PMID): 27004286Pages 398-405, Language: EnglishIbañez, Cristina / Catena, Andrés / Galindo-Moreno, Pablo / Noguerol, Blas / Magán-Fernández, Antonio / Mesa, FranciscoPurpose: Short- or long-term implant survival and success are related to peri-implant marginal bone loss (MBL), among other key factors. The purpose of this study was to analyze the role of clinical and implant-related variables in MBL over a long-term follow-up.
Materials and Methods: A retrospective study of 558 implants in 172 patients was conducted, analyzing the relationship between MBL and clinical, implant-related, and prosthetic design-related variables. MBL was measured on digital radiographs with specific software, using implant threads as reference.
Results: Linear mixed analysis revealed the following significant effects: a lower mean MBL for type IV bone (0.047 mm/year, 95% CI [-0.019, 0.119]) than for type III bone (0.086 mm/year, 95% CI [0.038, 0.138]), type II bone (0.112 mm/year, 95% CI [0.070, 0.167]), or type I bone (0.138 mm/year, 95% CI [0.052, 0.23]); an increased MBL of 0.033 mm/year for each increment of 1 mm in diameter (95% CI [0.002, 0.065]); a lower mean MBL in smooth implants (0.103 mm/year, 95% CI [0.090, 0.117]) vs rough implants (0.122 mm/year, 95% CI [0.102, 0.142]). The mean MBL was > 0 mm/year for all prostheses except for fixed complete dental prostheses.
Conclusion: Within the limits of a retrospective follow-up study, a lower mean peri-implant MBL was associated with type IV bone, a smaller diameter, a smooth surface, and a fixed complete dental prosthesis.
Keywords: alveolar bone loss, bone tissue, dental implants, implant-supported dental prosthesis
DOI: 10.11607/jomi.4373, PubMed ID (PMID): 27004287Pages 406-412, Language: EnglishDi Stefano, Danilo Alessio / Gastaldi, Giorgio / Vinci, Raffaele / Polizzi, Elisabetta Maria / Cinci, Lorenzo / Pieri, Laura / Gherlone, EnricoPurpose: The aim of this study was to investigate bone formation over time following maxillary sinus augmentation with an enzyme-deantigenic, bone collagen-preserving equine bone graft by retrospective assessment of histomorphometric data.
Materials and Methods: Records of patients with atrophic ridges who underwent maxillary sinus augmentation with the enzyme-deantigenic equine bone graft and two-step implant placement between 3 and 12 months after the sinus-augmentation surgery were assessed retrospectively. The histomorphometric data were clustered in three classes according to time of collection from the augmentation surgery and analyzed to assess newly formed bone deposition and residual biomaterial degradation rates. Data concerning the 36-month clinical follow-up were also assessed.
Results: Records of 77 patients and 115 biopsy specimens were retrieved, and histomorphometric data were clustered (3 to 5 months, n = 33; 6 to 8 months, n = 57; 9 to 12 months, n = 25). Mean minimum atrophic ridge thickness was 4.9 ± 0.5 mm (range, 4.0 to 7.1 mm). The amount of newly formed bone and residual biomaterial did not significantly differ among the three clusters. Qualitative analysis showed a denser trabecular structure in late (> 8 months) samples. At the 36-month clinical follow-up, no differences were found among the implant success rates in the three groups, according to the Albrektsson and Zarb criteria for success. The overall implant success rate was 98.3%.
Conclusion: Based upon this retrospective human study of 77 patients with 4 to 7 mm of residual bone, when enzyme-deantigenic equine bone is used for sinus augmentation, new bone formation occurs at an early time ( 3 months) after the grafting, and implant placement can be safely carried out as soon as 3 to 5 months after the augmentation surgery.
Keywords: biomaterial, bone remodeling, sinus augmentation, xenograft
DOI: 10.11607/jomi.4623, PubMed ID (PMID): 27004288Pages 413-423, Language: EnglishPrati, Carlo / Zamparini, Fausto / Scialabba, Viviana Stella / Gatto, Maria Rosaria / Piattelli, Adriano / Montebugnoli, Lucio / Gandolfi, Maria GiovannaPurpose: To evaluate the survival rate and marginal bone loss (MBL) of a calcium phosphate-blasted titanium implant inserted by a flap or flapless technique and to study the morphochemical characteristics of the implant surface.
Materials and Methods: Sixty out of 85 patients who received one or more implants were selected as eligible for this prospective longitudinal cohort clinical study. Titanium implants (n = 132) were placed in human healthy subjects using either a flap or flapless technique, selected on the basis of the best practice. The survival rate and MBL were evaluated after 3 months (preloading stress-free healing period) and after 6, 12, 24, and 36 months in relation to implant diameter, location, sex, and smoking habits. Surface morphochemical analyses were performed by environmental scanning electron microscopy connected with energy-dispersive x-ray (ESEM/EDX).
Results: The overall survival rate was 97.72%. After 3 and 36 months, MBL was 0.36 ± 0.66 mm and 1.09 ± 1.10 mm for the flapless group and 0.29 ± 0.51 mm and 1.03 ± 0.92 mm for the flap group. MBL showed a statistically significant increase with time (P = .0001), and differences were found at all times since 6 months. No statistical differences between the flapless and flap groups and sex were observed at any time, while MBL was significantly higher in the maxillary versus mandibular location (6, 12, and 24 months) and in smokers versus nonsmokers (6 months). Higher MBL in both groups was found for a smaller diameter (3.5 mm) than larger diameter (4.1, 5 mm). The surface showed a Ti-Al-V alloy displaying a uniform nanotexture.
Conclusion: The implant system showed a high survival rate and markedly lower MBL considering the limits for acceptable progression. Flapless and flap techniques demonstrated similar results of MBL at the preloading healing period and at the 6 months to 3 years postloading periods. Both surgical procedures induced an early MBL during the preloading stress-free period. Implant diameter, mandibular/ maxillary location, preloading stress-free period, and smoking habits affect MBL more than the type of surgery after both short- and long-term follow-up.
Keywords: calcium phosphate-blasted titanium surface, ESEM/EDX surface morphochemical characterization, flap surgery, flapless surgery, marginal bone loss, preload healing, survival rate
DOI: 10.11607/jomi.3805, PubMed ID (PMID): 27004289Pages 424-430, Language: EnglishHegazy, Salah / Elmekawy, Nesreen / Emera, Radwa M. K.Purpose: To compare peri-implant changes seen with two early loading protocols for modifying surface treatment of dental implants-one modifying the collar portion (Laser-Lok implant) and the other modifying the implant surface (nanosurface-treated implant).
Materials and Methods: Thirty-six completely edentulous patients were chosen for this research. Conventional complete dentures were constructed for all patients. Two implants were used for each patient corresponding to mandibular canines. The patients were classified into two groups. Eighteen patients in group 1 received 36 laser-collar-treated implants; 18 patients in group 2 received 36 nanosurface-treated implants. The implants were early loaded 2 weeks after implant insertion. The peri-implant outcome was evaluated using the following variables: (1) modified Plaque Index, (2) modified Bleeding Index, (3) probing depth, (4) implant mobility using the Periotest instrument, and (5) marginal bone loss as recorded at the time of the overdenture insertion and 6 and 12 months after insertion.
Results: At all times of the study, the differences between the groups were not significant with regard to peri-implant tissue changes around implants.
Conclusion: Both the laser collar- and nanosurface-treated dental implants showed the same peri-implant tissue changes with the early loading protocol. This study found that both early loading protocols are reliable, with good implant stability.
Keywords: implant early loading, mandibular overdentures, peri-implant outcome
DOI: 10.11607/jomi.3859, PubMed ID (PMID): 27004290Pages 431-438, Language: EnglishArRejaie, Aws / Al-Harbi, Fahad / Alagl, Adel S. / Hassan, Khalid S.Purpose: This study clinically and radiographically investigated the potential of platelet-rich plasma (PRP) gel combined with bovine-derived xenograft to treat dehiscence defects around immediate dental implants.
Materials and Methods: This study was performed on 32 sites from 16 patients who each received an immediate implant for a single tooth replacement at a maxillary anterior or premolar site. Patients were divided into two groups according to the augmented materials used. One group received an immediate implant and filling of defects using a PRP gel plus bovine-derived xenograft. The other group received an immediate implant and filling of defects with a bovine-derived xenograft without PRP gel. Cone beam computed tomography (CBCT) was taken before placement, and at 6 and 12 months postsurgery.
Results: Both treatment procedures resulted in significant improvements for the primary outcome regarding bone fill, as well as the marginal bone level. In addition, statistically significant differences were found in the bone density for the combined therapy compared with sites treated with bovine-derived xenografts alone (P ≤ .01).
Conclusion: Autogenous PRP gel combined with bovine-derived xenograft demonstrated superiority to the bovine-derived xenograft alone, which suggested that it could be successfully applicable for the treatment of dehiscence around an immediate dental implant. Moreover, CBCT can be used to measure dehiscence and to assess bone thickness along the implant.
Keywords: bone graft, buccal dehiscence, dentistry, immediate implant, platelet-rich plasma gel
DOI: 10.11607/jomi.4054, PubMed ID (PMID): 27004291Pages 439-447, Language: EnglishKitajima, Hajime / Ogawa, TakahiroPurpose: The objective of this study was to examine the success rate and development of implant stability of photofunctionalized implants with low and extremely low primary stability.
Materials and Methods: Primary implant stability was evaluated by measuring implant stability quotients (ISQs) at placement (initial ISQ). Of 301 consecutive implants placed over 2 years, 55 implants (in 38 patients) with initial ISQs less than 60 were included. All implants were photofunctionalized by chairside treatment with ultraviolet light for 15 minutes using a photo device immediately prior to placement, and the generation of superhydrophilicity and hemophilicity was confirmed. The rate of implant stability development was evaluated by calculating the osseointegration speed index (OSI), defined as the ISQ increase per month.
Results: Most of the 55 implants (90.9%) were in complex cases and placed in site-developmental sites with simultaneous or staged guided bone regeneration and/or sinus elevation or fresh extraction sites. The success rate was 98.2% after 2 to 3 years of follow-up. The ISQ for all implants was 50.4 ± 7.7 at placement and 74.3 ± 5.7 at stage-two surgery (P .001) after an average of 7.1 months of healing. All ISQ values were greater than 60 at the stage-two surgery. ISQ increases were inversely correlated with initial ISQ (R = 0.789) and resulted in consistently high ISQs at the stage-two surgery regardless of the degree of the initial ISQ. Implants with absent primary stability for which ISQ measurement was not possible at placement also attained ISQs of 75 or greater at the stage-two surgery. The OSIs of low initial stability (55 or lower) implants ranged from 3.9 to 4.7, which was considerably higher than the OSIs of as-received implants reported in the literature (0.36 to 2.8).
Conclusion: Photofunctionalized implants placed with low, extremely low, or absent primary stability showed a high success rate, which was corroborated with a rapid increase in implant stability during the healing. Photofunctionalization was more effective for implants with lower primary stability, indicating that the technology was particularly effective in mitigating the challenging conditions.
Keywords: hydrocarbon, implant stability quotient, superhydrophilic, superosseointegration, titanium, ultraviolet
DOI: 10.11607/jomi.4118, PubMed ID (PMID): 27004292Pages 448-458, Language: EnglishSchincaglia, Gian Pietro / Rubin, Satoko / Thacker, Sejal / Dhingra, Ajay / Trombelli, Leonardo / Ioannidou, EffiePurpose: Implant-supported mandibular overdentures (OVDs) have been proposed as the gold standard for the treatment of edentulous mandibles. There is limited evidence on the clinical outcomes of immediate loading of two unsplinted implants supporting a mandibular OVD. The purpose of this randomized controlled trial was to evaluate the performance of two unsplinted implants supporting a Locator-retained mandibular OVD over 12 months loaded immediately or after a delay.
Materials and Methods: Each patient received two implants 4.0 mm in diameter and 8 to 15 mm long. Locator-retained mandibular OVDs were connected to the implants either immediately (IL) or 3 months postsurgery (DL). The primary response variable was radiographic bone loss (RBL) at 6 and 12 months postsurgery. Implant length, insertion torque, implant failure, prevalence of maintenance visits, and prosthetic complications were also recorded.
Results: Thirty participants (15 in the IL and 15 in the DL groups) were evaluated at 12 months. The implant cumulative survival rates were 100% and 93% for DL and IL, respectively. The mean RBL from baseline to 1 year was 0.54 (± 0.5) mm and 0.25 (± 0.5) mm for DL and IL, respectively. A statistically significant difference was observed at 12 months, with less RBL in the IL group. Insertion torque and implant length were not correlated with RBL. Also, no difference in frequency of maintenance visits and prosthetic complications was reported between the groups.
Conclusion: Immediate loading of two unsplinted implants supporting a Locator-retained mandibular OVD seems to be a suitable treatment option. Significantly less RBL was observed after 1 year of loading around IL implants than around DL implants. Furthermore, neither implant length nor insertion torque seemed to affect RBL 1 year after surgical placement.
Keywords: immediate loading, overdenture
DOI: 10.11607/jomi.4142, PubMed ID (PMID): 27004293Pages 459-468, Language: EnglishHsu, Andrea / Seong, Wook-Jin / Wolff, Ryan / Zhang, Lei / Hodges, James / Olin, Paul S. / Hinrichs, James E.Purpose: The aim of this study was to determine if self-threading dental implants placed using stopper drills to bicortically engage both the alveolar crest and sinus floor (bicortical fixation) achieved primary and/or secondary stability comparable to that of short implants only engaging alveolar crest cortical bone (unicortical fixation) or implants engaging both the crest and sinus floor but via greenstick fracture and grafting (indirect sinus elevation).
Materials and Methods: Thirty-eight patients exhibiting 7 to 11 mm of bone coronal to the sinus floor as confirmed by preoperative CBCT were recruited. Forty-five implants were randomly assigned to one of the placement techniques. No patient received more than two implants, which were placed in opposite sides of the maxilla while using different surgical techniques. An Osstell ISQ was employed immediately after implant placement to measure stability six times in a buccolingual dimension. Secondary stability was measured at stage-two surgery after a 3- to 6-month healing period.
Results: The greatest primary implant stability was achieved via indirect sinus elevation. However, no statistically significant difference was found among the three surgical techniques (P = .13; bicortical fixation: 71.4 [standard error = 2.1]), unicortical fixation: 69.6 [2.1], indirect sinus elevation: 75.9 [2.3]). The three techniques had similar secondary stability (P > .999; 79.9 [1.2], 80.0 [1.2], and 80.0 [1.3], respectively). Baseline residual ridge height measured on CBCT was similar (P = .1; 8.8, 9.9, and 9.4 mm, respectively), but implant diameter and length placed in the maxilla differed (P = .03/P .001; 4.7/11.4 mm, 4.3/8.1 mm, and 4.7/11.8 mm, respectively). Primary implant stability was significantly correlated to CBCT bone density (r = 0.37).
Conclusion: Primary and secondary implant stabilities of bicortical fixation did not differ significantly from those of unicortical fixation and indirect sinus elevation. However, use of the bicortical fixation technique is warranted since it is simpler and more economical than indirect sinus elevation; plus, it allows for longer implants than the unicortical fixation while yielding similar secondary implant stability.
Keywords: bicortical fixation, initial implant stability
DOI: 10.11607/jomi.4288, PubMed ID (PMID): 27004294Pages 471-477, Language: EnglishBayani, Shahin / Masoomi, Fatemeh / Aghaabbasi, Sharereh / Farsinejad, AlirezaPurpose: The purpose of this study was to evaluate the effect of platelet-released growth factor (PRGF) and immediate orthodontic forces on the removal torque of miniscrews.
Materials and Methods: This study was conducted on three male dogs aged 6 to 8 months with a body weight of 17.6 to 18.4 kg. Sixty miniscrews were inserted in the posterior aspect of the femur. There were four groups, including loaded miniscrews with application of PRGF, unloaded miniscrews without application of PRGF, unloaded miniscrews with PRGF, and loaded miniscrews without PRGF. Twenty miniscrews were inserted in the femoral bone of one foot of each dog, including all the aforementioned subgroups. After 12 weeks, the miniscrews were removed by a removal torque tester device and measured in newton centimeters.
Results: The mean removal torque values in four groups of immediately loaded screws with PRGF, unloaded screws with PRGF, immediately loaded screws without PRGF, and unloaded screws without PRGF were 19.68, 21.74, 13.65, and 15.46 Ncm, respectively. It was shown that the mean removal torque value for the group with PRGF was significantly higher than that in the other groups (P = .0001). Although there was a tendency toward a decrease in removal torque value with immediate loading, it was not statistically significant (P = .21).
Conclusion: According to the results of this study, applying PRGF with miniscrews increased their stability, but the delivery of immediate force on miniscrews had no effect on the miniscrews' stability.
Keywords: immediate loading, miniscrew, PRGF, removal torque
Online OnlyDOI: 10.11607/jomi.4048, PubMed ID (PMID): 27004295Pages 1-10, Language: EnglishCinar, Duygu / Imirzalioglu, PervinPurpose: The purpose of this study was to determine the amount and localization of functional stresses in implants placed in two different bone types (type 3 and type 4) with three different crown heights in the atrophic posterior maxilla using finite element analysis.
Materials and Methods: A three-dimensional finite element model of the posterior maxilla was created from a computerized tomography image by using the Marc 2005 (MSC Software) program. Three different crown/implant ratios (1/1, 1.5/1, 2/1) in the first molar tooth zone were modeled. Type 3 and type 4 bone quality according to the classification system of Lekholm and Zarb was created. The total oblique force of 300 N with a 30-degree angle was applied from the locations of the mesiobuccal cusp (150 N) and the distobuccal cusp (150 N) of first molar teeth.
Results: For the implants, the highest stresses were observed around the implant neck at the crown/implant ratio of 2/1 (430.57 MPa). As the crown/implant ratio increased two times, the von Mises stresses increased at a rate of 47%. The highest tensile values exceeded the ultimate tensile strength of the cortical bone for all the designs. Also, the highest compressive values exceeded the ultimate compressive strength of the cortical bone in the 2/1 design for type 3 bone, and in the 1.5/1 and 2/1 designs for type 4 bone. As the crown/implant ratio increased from 1/1 to 2/1, the highest tensile value and the highest compressive value increased 13%. For the spongious bone, as the crown/implant ratio increased, the highest tensile value increased 42% and 85%, respectively. Tensile stresses increased at a rate of 26% in the 1/1 ratio, 30% in the 1.5/1 ratio, and 32% in the 2/1 ratio when the density of spongious bone decreased. Compressionrelated values also increased 34% in the 1/1 ratio, 35% in the 1.5/1 ratio, and 36% in the 2/1 ratio when the density of spongious bone decreased.
Conclusion: Compressive and tensile stresses formed mostly at the alveolar bone around the implant neck that was cortical bone. Thus, it had to be preserved during the surgical procedures. Deformation due to the stresses had great importance for the type IV spongious bone due to the increase caused by the higher crown height levels.
Keywords: single-tooth implants, crown-implant ratio, crown length
Online OnlyDOI: 10.11607/jomi.4202, PubMed ID (PMID): 26478973Pages 11-14, Language: EnglishGarcia-Garcia, Blas / Ruiz-Masera, Juan Jose / Zafra-Camacho, Francisco ManuelZygomatic implants are used to restore function in patients with highly edentulous atrophic maxillae, in which it is not possible to place conventional implants. The aim of this paper is to present a case of bilateral cutaneous fistula after placement of zygomatic implants and the treatment performed to resolve the condition, as well as to establish a hypothesis regarding the etiology of these lesions. Presented is a 59-yearold woman with an atrophic edentulous maxilla who received four zygomatic implants. At 8 months and 31 months after implant placement on the right and left sides, respectively, the patient developed inflammatory lesions in the lateral aspect of both orbits that evolved toward developing a fistula within weeks. The patient underwent surgery in both cases. Complications of zygomatic implants are relatively common but rarely involve the loss or removal of implants. In this case, the patient retained her implants, and several months after resection of both fistulae, the patient is asymptomatic without recurrence of the lesions. The probable cause of the occurrence of the fistula could be an accumulation of sinus mucosa remnants, periosteum, and bone particles at the malar level as a result of poor irrigation at the time of implant placement.
Keywords: contaminated debris, cutaneous fistula, zygomatic implants
Online OnlyDOI: 10.11607/jomi.4374, PubMed ID (PMID): 27004296Pages 15-17, Language: EnglishShah, Karnik / Yilmazi, BurakThis clinical report describes a method to create a proper emergence profile and accurately transfer it to the definitive impression, using an indirectly fabricated modified impression post. A provisional screwretained crown was indexed with a polyvinyl siloxane material. An autopolymerizing acrylic resin was used to modify an impression post on the polyvinyl siloxane index, which was then screwed onto the implant for the definitive impression after proper soft tissue healing. The indirectly fabricated modified impression post helped to transfer the contours to the definitive impression with minimal soft tissue irritation.
Keywords: emergence profile, implant, provisional crown
Online OnlyDOI: 10.11607/jomi.4509, PubMed ID (PMID): 27004297Pages 18-23, Language: EnglishVictorelli, Gabriela / Aloise, Antonio Carlos / Passador-Santos, Fabricio / Oliveira, Rafael de Mello e / Pelegrine, André AntonioPurpose: To evaluate the influence of bone marrow cells in the bone formation in an ectopic subcutaneous model in mice.
Materials and Methods: Six BALB/c mice were divided into three groups of two each. In all groups, xenograft was implanted subcutaneously. In the negative control group, the xenograft was hydrated with saline solution. In the positive control group, the xenograft was embedded with osteodifferentiated adult mesenchymal stem cells derived from the bone marrow. In the experimental group, the xenograft was embedded with bone marrow aspirate concentrate. After 4 weeks, the animals were sacrificed and prepared for histologic, histomorphometric, and immunohistochemical analysis. The following tissues were evaluated: preosteoid tissue, loose connective tissue, and remaining xenograft particles.
Results: There was a statistically significant difference (P = .008) in the preosteoid tissue area between the negative control group (0 ± 0%) and the other two groups, with 42 ± 11% for the experimental group and 56 ± 5% for the positive control group. Similarly, there was a statistically significant difference (P = .006) in the loose connective tissue area between the negative control group (49 ± 18%) and the other two groups, with 3 ± 9% for the experimental group and 0 ± 0% for the positive control group. Regarding the xenograft area, there was not a statistically significant difference between the three groups (P = .143).
Conclusion: The use of a mineralized scaffold loaded with either concentrated bone marrow aspirate or with osteogenically induced bone marrow mesenchymal stem cells favored the formation of osteoid tissue as opposed to the scaffold alone.
Keywords: bone marrow, cell transplantation, osteogenesis, stem cells
Online OnlyDOI: 10.11607/jomi.4414, PubMed ID (PMID): 27004298Pages 24-31, Language: EnglishPeker, Elif / Karaca, Inci Rana / Yildirim, BenayPurpose: The aim of this study was an experimental evaluation of the effectiveness of demineralized bone matrix (DBM) and collagenated heterologous bone graft (CHBG) used alone or in combination with platelet-rich fibrin on bone healing in sinus floor augmentation procedures.
Materials and Methods: In this study, 36 New Zealand rabbits were used. The bilateral sinus elevation was performed, and 72 defects were obtained. The rabbit maxillary sinuses were divided into four groups according to the augmentation biomaterials obtained: demineralized bone matrix (Grafton DBM Putty, Osteotech; DBM group), DBM combined with platelet-rich fibrin (PRF; DBM + PRF group), collagenated heterologous bone graft (CHBG; Apatos Mix, OsteoBiol, Tecnoss; CHBG group), CHBG combined with PRF (CHBG + PRF group). All groups were sacrificed at 2, 4, and 8 weeks after surgery for histologic, histomorphometric, and immunohistochemical analyses.
Results: The inflammatory reaction was moderate to intense at the second week in all groups and declined from 2 to 8 weeks. New bone formation was started at the second week and increased from 2 to 8 weeks in all groups. There was no significant difference in bone formation between the experimental groups that used PRF mixed graft material and control groups that used only graft material. The percentage of new bone formation showed a significant difference in DBM groups and DBM + PRF groups compared with other groups. There were osteoclasts around all the bone graft materials used, but the percentage of residual graft particles was significantly higher in CHBG groups and CHBG + PRF groups at the eighth week.
Conclusion: There is no beneficial effect of the application of PRF in combination with demineralized bone matrix or collagenated heterologous bone graft on bone formation in sinus floor augmentation. The results of this study showed that both collagenated heterologous bone graft and demineralized bone matrix have osteoconductive properties, but demineralized bone matrix showed more bone formation than collagenated heterologous bone graft.
Keywords: collagenated heterologous bone graft, demineralized bone matrix, maxillary sinus augmentation, platelet-rich fibrin