Sinus floor elevation procedures to enable implant placement and integration: techniques, biological aspects and clinical outcomes.

Implant treatment in an atrophied edentulous posterior maxilla constitutes a challenge for the therapeutic team. The authors of the present study acknowledge that modern micro-rough surface implants in lengths of about 8-10 mm or longer and of different brands are similarly successful. Consequently, the authors propose that the use of different sinus floor elevation techniques should be considered when < 8 mm of bone is available below the maxillary sinus. The type of sinus floor elevation technique selected is mainly based on residual vertical bone height, marginal bone width, local intrasinus anatomy and the number of teeth to be replaced, although other factors (such as surgical training and surgical experience) may have an impact. It is proposed that a transcrestal sinus floor elevation approach can be considered as a first-choice method for single tooth gaps in situations with sufficient width for implant placement and a residual bone height of 5-8 mm, while lateral sinus floor elevation, with or without grafting materials, is indicated when < 5 mm of bone is available and when several teeth are to be replaced. With regard to time of implant placement, a one-stage procedure is preferred provided that high primary stability can be ensured.

On the Early Mechanisms of Bone Formation after Maxillary Sinus Membrane Elevation: An Experimental Histological and Immunohistochemical Study.

BACKGROUND: Previous studies have shown predictable bone formation in the maxillary sinus after membrane elevation. However, how and where the bone is formed is not well understood. PURPOSE: The aim of the study was to histologically and immunohistochemically study the early bone formation events in primates after membrane elevation in the maxillary sinus. MATERIALS AND METHODS: Nine adult male tufted capuchin primates (Cebus apella) were included in the study. Eight animals were subjected to bilateral maxillary sinus membrane elevation using a lateral replaceable bone window technique. One oxidized dental implant was placed into the maxillary sinus cavity on both sides. In four animals, one sinus was left without any additional treatment, whereas the contralateral sinus was filled with autologous bone grafts from the tibia. In two animals, the implants were inserted under the elevated sinus membrane on both sides. In two animals, the sinus membrane was totally removed. The animals were euthanized after 10 or 45 days. One nonoperated animal representing pristine tissue conditions served as control. The maxillary sinuses with implants were retrieved and further processed for light microscopic ground sections or decalcified sections for immune-histochemical analyses. RESULTS: Bone formation started from the bottom of the sinus floor, sprouting into the granulation tissue along the implant surface under the elevated membrane irrespective of time and surgical technique. Bone formation was not seen in direct conjunction with the sinus membrane. A distinct expression of osteopontin was observed in the serous glands of the lamina propria close to the implant within all groups. CONCLUSION: Bone formation after sinus membrane elevation with or without additional bone grafts starts at the sinus floor and sprouts into the elevated space along the implant surface. The sinus membrane does not seem to present osteoinductive potential in sinus membrane elevation procedures in this study.

Follow-up study of implants with turned or oxidized surfaces placed after sinus augmentation.

PURPOSE: To compare long-term survival and clinical outcomes of endosseous implants with different surface characteristics in patients with sinus elevation procedures, autologous bone grafting, and delayed implant placement. MATERIALS AND METHODS: Implant survival, peri-implant soft tissue conditions, marginal bone level, intrasinus apical bone level, and sinus health were studied in patients subjected to autologous bone graft and delayed placement of implants with turned or oxidized surfaces. After a minimum of 5 years of functional loading, all patients were clinically examined regarding gingival pocket depth (PD) and bleeding on probing (BoP). The marginal bone level (MBL) was measured in intraoral radiographs. Cone beam computed tomography was used to evaluate the apical bone level (ABL) of the implants and intrasinus conditions. RESULTS: Twenty-eight patients received sinus elevation and a total of 92 dental implants. Thirteen patients received 47 implants with a turned surface, and 15 patients received 45 implants with an oxidized surface. Mean follow-up was 10 years (range, 5 to 19 years). No significant difference was found between the two implant surfaces in terms of PD, BoP, MBL, or ABL. Four patients (14%) exhibited radiographic signs of sinus pathology, with opacification, polyp-like structures, and thickening of the sinus membrane. Radiographic signs of sinus pathology were not correlated to implant survival or to the investigated parameters. CONCLUSION: Grafting of the maxillary sinus floor with intraorally harvested bone and delayed placement of either turned or oxidized implants results in equally high long-term survival rates, stable marginal and apical bone levels, and good peri-implant soft tissue health.

A retrospective comparison of oxidized and turned implants with respect to implant survival, marginal bone level and peri-implant soft tissue conditions after at least 5 years in function.

BACKGROUND: Long-term clinical follow-up studies comparing different implant surfaces with regard to survival and marginal conditions are rare. OBJECTIVES: The objective of this study was to compare the clinical performance of turned and oxidized implants after more than 5 years of loading. MATERIAL AND METHODS: One hundred three patients (43 men, 60 women; mean age 67.4 years, range 32-90) previously treated with 287 implants (Nobel Biocare AB, Gothenburg, Sweden), 133 with turned surface (MKIII, Nobel Biocare AB) and 154 with an oxidized surface (MKIII, TiUnite, Nobel Biocare AB) were examined after at least 5 years of loading (mean 82 months, range 60-93 months). The implants had been used for support of single crowns (33 patients/36 implants), partial bridges (39 patients/103 implants), or full bridges (31 patients/148 implants) following an early loading protocol (14 patients /54 implants), a one-stage protocol (32 patients/59 implants) or a two-stage protocol (57 patients/174 implants). Clinical examinations of bleeding on probing (BoP) and pocket depth (PD) were performed. Intraoral radiographs were used for assessments of marginal bone levels (MBLs). RESULTS: Seven turned implants and one oxidized implant failed, giving overall cumulative survival rates of 94.7 and 99.4%, respectively. There were no differences for BoP scores (0.5 ± 0.7 vs 0.4 ± 0.6) and PD measurements (1.7 ± 0.8 mm vs 1.8 ± 1.0 mm) parameters when comparing turned and oxidized implants, respectively. The mean MBL was 1.8 ± 0.8 mm and 2.0 ± 0.9 mm for turned and oxidized implants, respectively, after more than 5 years in function (NS). Frequency distribution of MBL loss showed no statistically significant differences between the two surfaces. A total of four implants (1.4%) (three oxidized and one turned) showed a PD > 3 mm, MBL > 4 mm, and BoP. However, none of these were associated with suppuration on examination. CONCLUSION: The present study does not state any differences in implant failure, MBL, presence of bleeding or PD around implants when comparing turned and oxidized titanium implants after at least 5 years of function.

Oxidized titanium implants (Nobel Biocare TiUnite) compared with turned titanium implants (Nobel Biocare mark III) with respect to implant failure in a group of consecutive patients treated with early functional loading and two-stage protocol.

OBJECTIVES: The purpose of this study was to compare two implant types of similar shape but with different surfaces with respect to implant failure. MATERIAL AND METHODS: A total of 136 patients were treated with Nobel Biocare Implants between January 2001 and December 2002. Totally 394 implants were placed, of which 199 were oxidized titanium implants (Nobel Biocare TiUnite and 195 with turned titanium surface (Nobel Biocare Mark III. Sixty-three patients underwent a one-stage surgical protocol, of which 24 were objected to early functional loading. The remaining 73 patients were treated with a traditional two-stage surgical protocol. All patients were followed for a minimum of 5 months after loading of the implants. Implants were classified as survivals when clinically stable and fulfilling purported function without any discomfort to the patient, with no signs of infection or ongoing pathologic process. RESULTS: Seven implants were lost in five patients (two males and three females), six in the maxilla and one in the mandible. All failed implants were Mark III implants, inserted following the traditional two-stage protocol. The implant success rate was 98.2% for the whole-patient group, divided as a 100% success rate following the implants with oxidized surface (Nobel Biocare TiUnite compared with a success rate of 96.4% with implants with turned surface (Nobel Biocare Mark III).