Pages 347, Language: English
PubMed ID (PMID): 16796276Pages 349-353, Language: English
Purpose: Osteoporosis and osteopenia are characterized by reductions in bone mass and may lead to skeletal fragility and fracture. The latest generation of oral bisphosphonate drugs, including alendronate and risendronate, has been approved for the prevention and treatment of osteoporosis. These medications are chemically absorbed into bone, decreasing osteoclast number and activity and thereby decreasing bone resorption. The purpose of this report is to present safety data from 2 controlled studies in patients receiving oral bisphosphonates.
Materials and Methods: Study 1 tested the effect of alendronate, an inhibitor of bone resorption, on alveolar bone. A total of 335 patients (162 men and 173 women, aged 30 to 79 years) with moderate or severe periodontal disease were randomized to either placebo or 70 mg alendronate once weekly. Alveolar bone height and safety were assessed over a 2-year period. Study 2 was a longitudinal single-blind controlled design comparing implant success in 50 consecutive patients (210 implants), 25 patients who received bisphosphonate therapy and 25 age-matched control subjects. Implant success and safety, including incidence of osteonecrosis of the jaws (ONJ), was blindly assessed for at least 3 years.
Results: In study 1, no cases of ONJ were observed in either treatment group. Furthermore, a trend toward lower incidences of infection and tooth loss was observed in the alendronate group. In study 2, no cases of ONJ were observed in either group, and implant success was greater than 99% in both groups.
Conclusion: On the basis of 2 controlled clinical studies, oral bisphosphonate usage was not associated with occurrence of ONJ. (Controlled Clinical Study)
PubMed ID (PMID): 16796277Pages 354-365, Language: English
Purpose: A major concern for implants that penetrate stratified epithelia is aggressive epithelial proliferation and migration. This epithelial downgrowth on the implant can be inhibited by a firm attachment between the underlying connective tissue and the implant. This study evaluates the connective tissue attachment to titanium implants with various well-defined surface topographies.
Materials and Methods: Titanium-coated epoxy replicas of polished (PO; Ra = 0.06 µm), finely blasted (FB; Ra = 1.36 µm), coarsely blasted (CB; Ra = 5.09 µm), acid-etched (AE; Ra = 0.59 µm), coarsely blasted and acid-etched (SLA; Ra = 4.39 µm), titanium plasma-sprayed (TPS; Ra = 5.85 µm), machined-like (ML; Ra=2.15 µm), and micromachined grooved (GR; V-shaped grooves 30 µm deep) surfaces were implanted subcutaneously in 74 rats for 1 to 11 weeks. Animals were sacrificed weekly. Surfaces were processed for histomorphometric evaluation of connective tissue attachment, capsule thickness, and where applicable, the degree of separation between the tissue and implant.
Results: A total of 153 test surfaces were analyzed. Statistical analysis revealed that textured and rough substrata, namely the GR, TPS, AE, CB, and SLA surfaces, exhibited significantly greater (P < .05) connective tissue attachment and thinner fibrous encapsulation when compared to the PO surface. Tissue separation from the implant interface was of significantly lower magnitude and frequency with the rough surfaces than with the PO surface.
Conclusions: The results indicate that rough implant surfaces are associated with stable connective tissue attachment, which has implications for their use in percutaneous and permucosal applications. In addition, data from the AE surface may indicate that the geometry of the surface irregularities can also be a significant determinant of the connective tissue response. (Basic Science) (More than 50 references)
Keywords: connective tissue attachment, fibrous capsule, surface topography, tissue-implant interface
PubMed ID (PMID): 16796278Pages 366-374, Language: English
Purpose: The investigators sought to determine whether maxillary sinus augmentation (MSA) was an independent risk factor for implant failure.
Materials and Methods: Using a retrospective cohort study design, the investigators enrolled a sample composed of subjects having 1 or more implants placed in the posterior maxilla. The primary predictor variable was MSA status at the time of implant placement (MSA present or absent). MSA consisted of a lateral window (external) or an osteotome (internal) procedure. The outcome variable was implant failure defined as implant removal. Demographic, health status, anatomic, implant-specific, abutment-specific, prosthetic, and perioperative variables were also examined. Overall implant survival was estimated using Kaplan-Meier analysis. Risk factors for implant failure were identified using Cox proportional hazard regression models.
Results: The sample consisted of 318 patients and 762 posterior maxillary implants. The mean duration of follow-up was 22.50 ± 19.06 months. The 5-year survival rates for implants in the ungrafted and grafted posterior maxilla were 88.0% and 87.9%, respectively (P = .08). After adjustment for covariates, MSA status was not an independent risk factor for implant failure (P = .9). Tobacco use (P < .001), implants replacing molars (P < .001), and 1-stage implants (P < .001) were statistically associated with an increased risk for implant failure.
Discussion: MSA status was not associated with implant failure risk. This finding may be subject to selection bias, as successful MSA was requisite prior to implant placement.
Conclusion: MSA status was not associated with an increased risk for implant failure. Of the 3 factors associated with an increased risk for failure, tobacco use and implant staging may be modified by the clinician to enhance outcome. (Retrospective Clinical Cohort Study) (More than 50 references)
Keywords: implant failure, retrospective cohort studies, risk factors, sinus augmentation
PubMed ID (PMID): 16796279Pages 375-379, Language: English
Purpose: The objective of this study was to compare the osseointegration of implants in rats in sites prepared with an Er:YAG laser with osseointegration in sites prepared using a conventional drill by assessing the percentage of bone-implant contact (BIC).
Materials and Methods: Osteotomies were prepared with an Er:YAG laser in the tibiae of 18 rats (the test group) and drill-prepared with a 1.3-mm-wide surgical implant drill at 1,000 rpm with simultaneous saline irrigation in the tibiae of another 18 rats (the control group). Acid-etched titanium alloy implants (2 3 8 mm) were placed in the tibiae, engaging the opposite cortical plate. The Er:YAG laser was used with a regular handpiece and water irrigation (spot size, 2 mm; energy per pulse, 500 to 1,000 mJ; pulse duration, 400 ms; and energy density, 32 J/cm2). Nine animals from each group were sacrificed after 3 weeks of unloaded healing; the remainder were sacrificed after 3 months. The tissues were fixed and prepared for histologic and histomorphometric evaluation.
Results: Statistical analysis showed significant differences between the 2 groups at both 3 weeks and 3 months. After 3 weeks of unloaded healing, the mean BICs (±SD) were 59.48% (± 21.89%) for the laser group and 12.85% (± 11.13%) for the control group. Following 3 months of unloaded healing, the mean BICs (±SD) were 73.54% (± 11.53%) for the laser group and 32.6% (± 6.39%) for the control group.
Discussion: Preparation of the implant sites with the Er:YAG laser did not damage the interface; the healing patterns presented were excellent.
Conclusions: Based on the results of this study, it may be concluded that the Er:YAG laser may be used clinically for implant site preparation with good osseointegration results and bone healing and with a significantly higher percentage of BIC compared to those achieved with conventional methods.
PubMed ID (PMID): 16796280Pages 380-391, Language: English
Purpose: Osteogenic alveolar distraction remains in an experimental stage. The present study aimed to compare histologic and histomorphometric results with 2 different consolidation periods (4 and 8 weeks) to determine which period obtained better bone quality after distraction with a prototype alveolar distractor.
Materials and Methods: Five beagle dogs were used. Four underwent alveolar distraction in an edentulous segment of the right mandible. After a 7-day latency period, distraction was carried out at a rate of 1 mm/d for 5 days; the consolidation period was 4 weeks in 2 dogs (group 1), and 8 weeks in the other 2 (group 2). The fifth dog was used as control (group 3); it underwent removal of its right premolars but not distraction. Histologic and histomorphometric studies were conducted.
Results: One animal from each distraction group was withdrawn from the study because of wound dehiscence that allowed invasion of mucosa into the distraction chamber, which was incompatible with bone regeneration. In the group 1 animal, a predominance of immature woven bone was observed in the distraction chamber, whereas the group 2 animal showed a predominance of immature parallel-fibered bone. The group 1 and 2 animals that remained in the study differed in bone area density in the distraction chamber (36.61% ± 9.79% versus 58.72% ± 8.30%), bone perimeter in the distraction chamber (262.89 ± 10.46 mm versus 201.44 ± 22.64 mm), total height attained (21.31 ± 0.32 mm versus 18.37 ± 0.50 mm), lingual trabecular width (134.00 ± 15.56 versus 229.50 ± 29.24), buccal trabecular width (90.00 ± 4.24 mm versus 154.50 ± 21.64 mm), lingual osteoid area density (4.08% ± 0.46% versus 1.61% ± 0.33%), and buccal osteoid area density (3.75% ± 1.28% versus 2.09% ± 0.79%).
Conclusion: Quantitative and qualitative differences in newly formed bone were observed after 4 and 8 weeks of consolidation. These preliminary results serve as a basis for further experimental research with larger samples and for clinical studies. (Animal Study) (More than 50 references)
Keywords: alveolar distraction, consolidation period, experimental oral surgery
PubMed ID (PMID): 16796281Pages 392-398, Language: English
Purpose: In the present study solid monocortical hipbone onlay grafts of the maxilla were analyzed histologically after a healing period of 3 months. The clinical success of the implants placed in the grafted bone was evaluated.
Materials and Methods: Nineteen patients underwent augmentation with avascular iliac bone. A 2-stage procedure was performed with a 3-month healing period between graft and implant placement. At implant placement bone biopsy samples were taken at the proposed implant sites.
Results: Of the 117 implants placed, 1 was not osseointegrated at the time of abutment connection. No implants were lost after loading during an observation period of up to 3 years. Clinical appearance of the augmented bone after 3 months showed a dense cortical layer with good blood perfusion. Histologic specimens were analyzed quantitatively and showed an average of 43.2% newly formed bone.
Discussion: Histomorphometry showed that the amount of newly formed bone after 3 months was comparable to that found after a healing period of 4.5 months. The clinical success of the implants placed after the shortened healing period was comparable to that found in nonaugmented bone.
Conclusion: This study showed that after avascular iliac bone grafting, 3 months of revascularization was sufficient to ensure the secure placement of dental implants in second-stage surgery for this patient population.
Keywords: dental implants, iliac bone grafting, onlay bone grafting
PubMed ID (PMID): 16796282Pages 399-404, Language: English
Purpose: The aim of the present study was to describe experiences of 11 consecutively treated patients who received zygomatic implants. Patient results were assessed through clinical and radiographic evaluations of tissue conditions, including resonance frequency analysis (RFA).
Materials and Methods: Eleven patients were treated with implant-retained fixed prostheses. A total of 64 implants were placed, 22 of which were placed in the zygoma. Fixed prostheses were removed to allow clinical and radiographic evaluations at a follow-up visit 18 to 46 months following implant placement. RFA was performed on all implants. A visual analog scale was used to assess patient satisfaction before and after treatment.
Results: All patients received implant-supported prostheses. All zygomatic implants demonstrated clinical signs of osseointegration. One anterior implant was lost during follow-up. Mean ISQ values for the zygomatic and anterior implants were 65.9 (range, 42 to 100) and 61.5 (range, 48 to 71), respectively. Twenty-four implants showed moderate inflammation, with 3 exhibiting severe inflammation. Most anterior implants (75.6%) showed a marginal bone recession of 1 thread or less. Four zygomatic implants showed bone loss of 4 to 5 threads, and 5 zygomatic implants exhibited no marginal bone support. Patients described significant improvement in chewing ability and esthetics but did not describe changes in speech.
Discussion: The use of zygomatic implants can help the clinician avoid the need for bone grafting and reduce morbidity. In addition, it can shorten the treatment time considerably.
Conclusion: This preliminary report demonstrates that zygomatic implants can provide posterior support to fixed prostheses in patients who lack bone volume to place conventional implants without encroaching upon the maxillary sinus. (Before-and-After Study)
PubMed ID (PMID): 16796283Pages 405-412, Language: English
Purpose: The aim of this retrospective study was to examine the peri-implant tissue status at immediately provisionalized anterior maxillary implants 12 to 30 months following tooth replacement.
Materials and Methods: This is a retrospective study of 43 microthreaded, TiO2 grit-blasted implants placed in healed ridges and immediate extraction sockets to restore maxillary anterior and premolar teeth in 28 patients. The cortical bone position relative to the implant reference point was evaluated at implant placement and 6 to 30 months following restoration. Radiographs were assessed using 73 magnification. The distance from the reference point to the cortical bone was measured to ± 0.1 mm. The relationship of the peri-implant mucosa to the incisal edge of the definitive prosthesis was recorded.
Results: Four implants in 3 individuals failed during the first 6 weeks following placement and provisional loading. Cortical bone adaptation from the time of implant placement up to 30 months following restoration ranged from 0.0 mm to 1.5 mm (average, 0.33 ± 0.40 mm mesially and 0.28 ± 0.37 mm distally). The mean radiographic measurements from the interproximal crestal bone to the contact point were 4.53 ± -0.91 mm (mesial) and 4.06 ± 0.98. Maintenance and growth of papilla was observed in this group of immediate provisionalized single-tooth implants. Definitive abutment or abutment screw loosening was not observed.
Discussion: The linear clinical and radiographic measures of peri-implant tissue responses suggest that proper implant placement is followed by supracrestal biological width formation along the abutment and preservation of toothlike tissue contours. This may influence buccal peri-implant tissue dimensions.
Conclusions: Generalized maintenance of crestal bone and the increased soft tissue dimension with maintenance of peri-implant papilla were identified as expected outcomes for immediate loading/provisionalization of microthreaded, TiO2 grit-blasted implants. Control of peri-implant tissues can be achieved to provide predictable and esthetic treatment for anterior tooth replacement using dental implants. (Case Series)
PubMed ID (PMID): 16796284Pages 413-420, Language: English
Purpose: The purpose of this article was to evaluate the survival rate of 34 remote anchorage implants placed in 18 patients from placement to uncovering, prior to any prosthetic loading.
Materials and Methods: A total of 18 patients (9 women and 9 men with a mean age of 63 years) who required rehabilitation with a fixed prosthesis because of severely atrophic maxillae (including 1 patient who had undergone primary and secondary cleft lip and palate repair), traumatic maxillary bone loss, and maxillectomy procedures received 1 or 2 zygomatic implants and 2 to 4 standard maxillary dental implants. The survival rate of the 34 zygomatic implants from placement to uncovering was investigated. Aspects of the placement technique or postoperative complications related to surgical procedures likely to affect the implant failure rate were detected and critically discussed.
Results: Osseointegration was evaluated using the reverse torque test and percussion after uncovering. Only 1 patient (5.6%) sustained postoperative clinical complications during the evaluation period which resulted in the loss of both zygomatic implants (5.9%).
Conclusion: Although the handling of this anchorage implant system is somewhat complex, and the design has certain shortcomings, it might be an alternative to more extensive bone augmentation procedures. However, rehabilitation of partially or completely edentulous patients with fixed implant-supported prosthesis is only feasible when 2 to 4 standard implants are placed in the anterior maxilla and splinted with the zygomatic implants. (Case Report)
Keywords: atrophic maxilla, bone augmentation, bone grafting, maxillectomy, osseointegration, reconstruction, zygomatic implants
PubMed ID (PMID): 16796285Pages 421-425, Language: English
Purpose: The purpose of this study was to evaluate indications, surgical problems, complications, and treatment outcomes related to the placement of zygomatic implants. A second aim was to determine any prosthetic difficulties and complications.
Materials and Methods: Twenty-five zygomatic implants were placed in 13 patients between April 1999 and December 2001. The patient age range was between 49 and 73 years, with a mean age of 59 years. All patients showed severe resorption of alveolar bone in the maxilla. All but 2 patients were smokers. Two patients had a history of cleft palate surgery, and 2 patients were known to be bruxers. Standard recommended surgical protocol was followed, and treatment was performed under general anesthesia. After abutment surgery, 9 patients received bar-retained overdentures, and 4 patients received fixed prostheses.
Results: No implants were lost, and few surgical complications were experienced. The follow-up period was 11 to 49 months.
Discussion: Although surgical problems precipitated by difficult anatomy in cleft patients and a patient with reduced interarch access were experienced, the results were favorable. Fabricating a functional and esthetic prosthesis can be a challenge.
Conclusion: Zygomatic implants provide a treatment option for patients with severe maxillary resorption, defects, or situations where previous implant treatment has failed. In this experience, treatment with zygomatic implants was a predictable method with few complications, even in a group of patients that would not be considered ideal for implant treatment. (Case Series)
Keywords: implant-supported dental prostheses, zygomatic implants
PubMed ID (PMID): 16796286Pages 426-432, Language: English
Purpose: The clinical and radiologic results of bone substitute application in the sinus elevation procedure were evaluated for up to 4 years after a grafting procedure followed by implant placement.
Materials and Methods: Between 1997 and 2001, augmentation of the maxillary sinus floor with alloplastic or xenogenic materials was performed in 34 nonsmoking patients with generally good health. However, only 18 patients attended all of the required annual clinical and radiographic examinations and thus were included in the study. Mean follow-up after implantation was 29 months.
Results: At the second-stage surgery all the implants were osseointegrated, except for 1 Frialit-2, which was removed. Following prosthetic rehabilitation no implant was lost after 4 years of function, for a prosthetic success rate of 100%. The cumulative implant survival rate after 48 months was 97% (36 of 37 implants).
Discussion: Osseointegrated implants are a reliable treatment option for restoring the posterior maxilla, and final predictability was not influenced by their placement in augmented areas after sinus elevation with bone substitutes.
Conclusions: The survival rate obtained with this study is similar to that expected for implants placed in nongrafted areas. This study showed that alloplasts and xenogenic materials are reliable for bone regeneration in the subantral cavities, as they showed very low resorption in the present study.
Keywords: allografts, dental implants, maxillary sinus elevation, xenografts
PubMed ID (PMID): 16796287Pages 433-438, Language: English
Purpose: The purpose of this study was the determination of time-dependent volumetric changes of particulate sinus inlay grafts. A mixture of phycogenic hydroxyapatite (Algipore/C-Graft) and autologous bone collected from the surgical access area was used as the grafting material.
Materials and Methods: Thirty-three sinus floor augmentations using phycogenic hydroxyapatite combined with autologous bone collected at the augmentation site and venous blood were performed on 18 patients aged 57.4 ± 12.5 years (mean ± SD) with severe atrophy of the posterior maxilla. Graft volume was measured 1 to 14 days postoperatively and before the placement of dental implants 6.1 ± 2.1 months later (mean ± SD; range, 4 to 11 months) to evaluate the amount of time-dependent resorption of the implanted material on computerized tomographic (CT) images of the augmented region. The images were put into Digital Imaging and Communications in Medicine (DICOM) format and evaluated using the software library Analyze. The implanted bone replacement material was plotted manually on each CT slice, and the volume of the implanted material was calculated.
Results: The average volume loss of the bone replacement material during the observation period was 13.9% ± 1.9% (mean ± SEM). All sinus floor augmentations healed without complications except for delayed membrane exposure in 2 cases.
Discussion: The results indicate that the graft material, a mixture of Algipore, bone chips from the access area, and venous blood, exhibited a small volume loss over a period of approximately 6 months, thus providing predictable height for second-stage implant surgery.
Conclusion: Further investigations are needed to evaluate long-term stability and implant success.
PubMed ID (PMID): 16796288Pages 439-444, Language: English
Various terms, etiologies, and treatment strategies have been suggested in conjunction with bone loss limited only to the apical portion of an implant that remains otherwise well osseointegrated. Proposed etiologic factors include bone overheating, microbial involvement of adjacent teeth, pre-existing bone infection, and overload. However, the mandible and maxilla seem to have different predispositions in response to these causative agents. Treatment protocols for peri-implant infection have included minimally invasive approaches such as granulation tissue removal and detoxification of the implant surface, as well as more aggressive measures. This case report demonstrates the achievement of osseous healing and reosseointegration in a patient who presented with presented apical bone loss and signs of infection around a mandibular implant. Reosseointegration was achieved following an intraoral apicoectomy-like approach, ie, removal of the infected nonintegrated portion of the implant, and meticulous debridement of the granulation tissue. A literature review of 13 relevant published studies was conducted. The current understandings regarding the etiology and treatment strategies for management of apical bone loss around dental implants are summarized and presented. (Case Report)
Keywords: apical bone loss, apicoectomy, bone-implant interface, dental implants, implant periapical lesion, osseointegration failure
PubMed ID (PMID): 16796289Pages 445-449, Language: English
Purpose: Narrow edentulous alveolar ridges less than 5 mm wide require horizontal augmentation for the placement of screw-type dental implants. A staged approach to ridge splitting in the mandible to decrease the risk of malfracture during osteotomy is presented.
Materials and Methods: Five consecutive patients with 6 long-span edentulous areas of the mandibular ridge were included in this study. After corticotomy of a rectangular buccal segment and a 40-day healing period, the mandibular ridge was split, leaving the buccal periosteum attached to the lateralized segment. Seventeen dental implants were placed, and the gap between the implants and the bone filled with a mixture of venous blood and a porous algae-derived hydroxyapatite.
Results: All buccal segments fractured as planned at the basal corticotomy during ridge splitting. After 6 months, all implants were stable and surrounded by bone; prosthetic loading with fixed partial dentures was successful in all cases.
Discussion: In the mandible, greenstick fracture during widening with osteotomes has not been controllable to date because of cortical thickness of the bone; the risk of malfracture during single-stage ridge splitting was high. With this approach, the location of the greenstick fracture is predetermined, and the perfusion for the buccal segment remains intact, although vascularization shifts from internal perfusion from spongy bone after the first intervention to external perfusion from the periosteum after the second intervention. The buccal cortical segment remains a pedicled graft after ridge splitting.
Conclusion: The preliminary results of this report indicate that staged ridge splitting can be a safe technique which overcomes the problems associated with single-stage ridge expansion/ridge splitting procedures without causing significant delay in treatment.
PubMed ID (PMID): 16796290Pages 450-454, Language: English
Purpose: In space, astronauts are subject to microgravity, which reduces skeletal loading and osteoblast function and can cause bone resorption and a decrease in bone density. No known research to date has studied the effect of microgravity on dental implants. This study evaluated peri-implant bone changes around a dental implant placed in a French astronaut who spent 6 months in Russia's Mir Space Station.
Materials and Methods: Measurements were performed by 2 examiners before the flight (baseline), after the flight (stage 1), and following a recovery period (stage 2). Standardized periapical radiographs were taken, and data were recorded using a photomicroscope and a measuring scale.
Results: Cumulatively, the implant sustained 0.43 mm of mesial bone gain and 0.31 mm of distal bone loss.
Discussion: The observed peri-implant bone height changes were within normal limits and the implant appeared very stable during the course of this study.
Conclusion: Peri-implant bone levels remained stable after 6 months in microgravity, and the implant continued to function without complications. (Case Report)
Keywords: dental implants, microgravity, peri-implant bone, space flight
PubMed ID (PMID): 16796291Pages 455-458, Language: English
The objective of the present report was to present a modification of the standard sinus lift procedure. The modification consists of the creation of a mechanism facilitating maxillary sinus mucosa lift by means of negative pressure and simplification of the instrumentation used for this procedure. With the change in technique, maintenance of the success and predictability rates observed in the literature is possible. (Technical Note/Case Report)
Keywords: bone transplantation, sinus augmentation
PubMed ID (PMID): 16796292Pages 459-464, Language: English
A case is presented in which diffuse lymphangiomatosis resulted in the complete loss of the maxillary dentoalveolar complex and underlying basal bone. The complex investigation and treatment of this patient over a 10-year period is presented, and the importance of a multidisciplinary team approach in providing a functional and esthetic rehabilitation is highlighted. The use of a vascularized bone graft based on the deep circumflex iliac artery and subsequent restoration with an implant-supported prosthesis is described. (Case Report)
Keywords: dental implants, diffuse lymphangiomatosis, maxilla, multidisciplinary approach, vascularized deep circumflex iliac artery grafts
PubMed ID (PMID): 16796293Pages 465-470, Language: English
Purpose: To evaluate the 3-dimensional accuracy of dental implant drilling in a computer-assisted navigation (CAN) system using simulated mandible models.
Materials and Methods: Eight acrylic resin models were fabricated to simulate human mandibles containing mandibular canal (MC). Computerized tomography (CT) scans were obtained for each model, and the data were transferred to the system for dental implant planning. The models were mounted on a phantom head to simulate surgical situation. The assessment parameters included entry point localization, drill path angulation, and drilling depth, which were directly measured by sectioning of the models.
Results: Eighty drill holes were made on the 8 models. The entry point localization showed a mean deviation of 0.43 mm (range, 0 to 2.23 mm; SD, 0.56 mm) from the plan. The angulation showed a mean deviation of 4.0 degrees (range, 0 to 13.6 degrees; SD, 3.5 degrees). The drill aimed at stopping as close to the upper border of the MC as possible without perforating it, and 65% (52) of the drill holes managed to come within 1 mm. Another 5% of the holes stopped 1 to 2 mm above the MC. None of the drill holes stopped more than 2 mm above the MC. However, 30% (24 of 80) of the drill holes perforated the upper border of MC, and the mean depth of perforation was 0.37 mm (range, 0.01 to 1.04 mm; SD, 0.28 mm). Discussion and
Conclusion: The CAN system identified the entry location and angulation with mean deviations of 0.43 mm and 4 degrees, respectively. About two thirds of the drillings achieved accuracy within 1 mm above the MC. Thirty percent perforated into the MC, and the maximal depth was 1.04 mm. In the planning stage, the maximal depth of the implant should be at least 1.1 mm above the superior border of MC as a safety margin. (Technical Report)
Keywords: computer-assisted navigation, dental implants, image-guided navigation
PubMed ID (PMID): 16796294Pages 471-475, Language: English
In this article, a procedure involving 2-stage alveolar distraction osteogenesis using eccentric distraction devices for the augmentation of resorbed transplanted iliac bone following mandibular tumor resection is presented. A 6-month consolidation period was allowed between the first and second distractions, and endosseous implants were placed 4 months after the second distraction. Computerized tomographic images obtained before the implantation revealed that, 10 months after the first distraction, the bone generated still showed lower density compared with the basal bone, but the bone from both distractions showed enough maturity for implantation. It may be concluded that 2-stage alveolar distraction osteogenesis can be a useful and safe procedure for excessive alveolar lengthening if a sufficiently long consolidation period is allowed. (Case Report)
Keywords: alveolar augmentation, distraction osteogenesis, eccentric distractors, iliac bone grafting
PubMed ID (PMID): 16796295Pages 476-480, Language: English
A surgical approach is presented that enables the clinician to repair apical bony defects during immediate dental implant placement without compromising the integrity of the coronal bone and gingiva. This apical surgical technique retains the soft tissue form in the coronal aspect of the gingiva and allows the clinician to repair the apical bone loss or fenestration. A clinical case is presented to describe the technique. This technique is utilized in cases of immediate implant placement. After extraction of the tooth, the socket is evaluated. In cases where coronal bone is intact but apical bone is deficient, a flap technique is utilized to expose the defect. The implant osteotomy is prepared, and the implant is placed. A healing cap or gingival prosthetic component is connected. The bony defect is repaired with a bone graft and, where necessary, a membrane. The apicoectomy flap is sutured. The clinical results obtained using this technique will enable the clinician to accomplish the bone regenerative procedure without extending the flap to the coronal aspect of the socket during immediate implant placement. This technique assists in the maintenance and integrity of the soft tissue form, which is critical for optimal esthetic results. (Case Report)
Keywords: apicoectomy, bony defects, dental implants, esthetics, immediate implant placement, soft tissue integrity
PubMed ID (PMID): 16796296Pages 481-485, Language: English
This patient report describes the secondary reconstruction of a hemimandibular and condylar defect and the dental restoration of a 56-year-old woman who had been subjected to radical ablative surgery 30 years earlier to remove a tumor. In the first phase, a fibula free flap was used in combination with a total TMJ prosthesis for the reconstruction of the hemimandible and condyle. Secondly, 3 endosseous implants were placed in the residual mandible. These implants were used to support an overdenture prosthesis that has remained in continuous function for a period of 2 years. (Case Report)
Keywords: dental implants, dental prostheses, fibular free flap, mandibular reconstruction, temporomandibular joint prostheses