Comparative study of immediately inserted dental implants in sinus lift: 24 months of follow-up

Survival rate of implants following maxillary sinus floor augmentation using freeze-dried allografts vs bovine derived xenografts: A retrospective multicenter study

INTRODUCTION

This study aims to compare the surgical and clinical complications, and the dental implant survival rate after maxillary sinus floor augmentation using demineralized freeze-dried bone allografts (DFDBA) versus bovine derived xenografts.

MATERIAL AND METHODS

A retrospective study enrolled 107 patients (52 males and 55 females, mean age group 1: 54,4 years; group 2: 56,4 years) requiring maxillary bone reconstruction prior to implantation. A total of 141 sinuses were grafted and 191 implants were placed. Data on various variables, including patient characteristics, implant placement details, and outcomes, were collected through medical records and patient questionnaires.

RESULTS

The study found no significant differences in implant survival rates between the two groups (94,0% versus 94,4%; p = 0,919). Overall complications were observed in 19.6% of patients, with a higher incidence in the allograft group (23,6% versus 15,4%; p = 0,283). Multiple logistic regression analysis identified a two-stage surgical protocol (OR= 2,8; p = 0,045), and a preoperative alveolar ridge height of less than 4 mm (OR= 5,3; p = 0,004) as significant predictors of complications. The risk of implant failure was raised by a preoperative alveolar ridge height of less than 4 mm (OR= 6,1; p = 0,038) and smoking (OR= 5,8; p = 0,012).

DISCUSSION

DFDBA is a reliable treatment option for extensive rehabilitation of atrophic maxilla, with a success rate comparable to xenografts used in sinus augmentation. Implant failure was significantly correlated with smoking and a residual ridge height of less than 4 mm.

15-Year Retrospective Study on the Success Rate of Maxillary Sinus Augmentation and Implants: Influence of Bone Substitute Type, Presurgical Bone Height, and Membrane Perforation during Sinus Lift

Objectives

To evaluate the success rate of bone grafts and implants carried out at the Latin American Institute for Research and Dental Education (ILAPEO), considering the following: (i) the different pure bone substitutes (autogenous, xenogeneic, and alloplastic), (ii) the presurgical bone height, and (iii) how the treatment is compromised when membrane perforation occurs during sinus lift in maxillary sinus surgeries. Material and Methods. The initial sample comprised 1040 records of maxillary sinus lifting surgeries. After evaluation, the final sample retained 472 grafts performed using the lateral window technique with a total of 757 implants. The grafts were divided into 3 groups: (i) autogenous bone (n = 197), (ii) xenogenous bovine bone (n = 182), and (iii) alloplastic material (n = 93). One calibrated examiner classified the sample into two groups based on the residual bone height (<4 mm and ≥4 mm) of the area of interest measured on parasagittal sections of tomographic images. Data on membrane perforation occurrences in each group were collected; qualitative variables were described using frequency, expressed as percentages. The Chi-square test was used to analyze the success of the graft types and the survival rate of the implants as a function of the grafted material and the residual bone height. The Kaplan-Meier survival analysis was used to calculate the survival rate of bone grafts and implants according to the classifications adopted in this retrospective study.

Results

The success rate of grafts and implants was 98.3% and 97.2%, respectively. There was no statistically significant difference in the success rate among the different bone substitutes (p = 0.140). Only 8 grafts (1.7%) and 21 implants (2.8%) failed. There was a greater success rate for both grafts (96.5%) and implants (97.4%) when the bone height was ≥4 mm. The success rate in the 49 sinuses in which the membrane was perforated was 97.96% for the grafts and 96.2% for the implants. The follow-up periods after rehabilitation ranged from 3 months to 13 years.

Conclusions

Within the limitations of the data analyzed in this retrospective study, maxillary sinus lift was a viable surgical technique that enabled implant placement with a predictable long-term success rate, regardless of the type of material used. The presence of membrane perforation did not interfere with the success rate obtained for grafts and implants.

Radiographic Evaluation of Bone Remodeling after Additively Manufactured Subperiosteal Jaw Implantation (AMSJI) in the Maxilla: A One-Year Follow-Up Study

Additively manufactured subperiosteal jaw implants (AMSJI) are patient-specific, 3D-printed, titanium implants that provide an alternative solution for patients with severe maxillary bone atrophy. The aim of this study was to evaluate the bony remodeling of the maxillary crest and supporting bone using AMSJI. Fifteen patients with a Cawood–Howell Class V or greater degree of maxillary atrophy were evaluated using (cone beam) computed tomography scans at set intervals: one month (T1) and twelve months (T2) after definitive masticatory loading of bilateral AMSJI implants in the maxilla. The postoperative images were segmented and superimposed on the preoperative images. Fixed evaluation points were determined in advance, and surface comparison was carried out to calculate and visualize the effects of AMSJI^TM on the surrounding bone. A total mean negative bone remodeling of 0.26 mm (SD 0.65 mm) was seen over six reference points on the crest. Minor bone loss (mean 0.088 mm resorption, SD 0.29 mm) was seen at the supporting bone at the wings and basal frame. We conclude that reconstruction of the severely atrophic maxilla with the AMSJI results in minimal effect on supporting bone. Reduced stress shielding with a biomechanically tuned subperiosteal implant does not induce radiographically significant crestal bone atrophy.

Distal Displacement of Maxillary Sinus Anterior Wall Versus Conventional Sinus Lift with Lateral Access: A 3-Year Retrospective Computerized Tomography Study

Background: The present study is designed to compare the outcomes of two sinus augmentation procedures: distal displacement of the anterior wall versus standard sinus lifting and grafting with a lateral window approach. Methods: In the displacement group, a localized surgical fracture of the sinus floor achieved through an electromagnetic device results in the distal displacement of the anterior wall. In the filling group, sinus lifting (with lateral access) and grafting with particulate xenogeneic bone substitute was performed. Bone volume beneath the maxillary sinus was investigated with computerized tomography after baseline and postoperative data superimposition. Clinical and radiological outcomes over three years had been evaluated. Results: Forty-three dental implants were selected. The two sinus lift procedures significantly increased the bone volume (p-value ≤ 0.0017) in the displacement group from 1.17 ± 0.34 to 1.53 ± 0.39 cc, with a final bone gain of +0.36 ± 0.17 cc, and in the filling group from 1.24 ± 0.41 to 1.94 ± 0.68 cc, with a bone augmentation of +0.71 ± 0.31 cc. No events of dental implant bulging into the maxillary sinus occurred. Two implants failed early on in the filling group, attesting the 3-year survival rate of 92.6% (CI95%: 82.7–100%). Marginal bone loss at the distal aspect was 1.66 ± 0.72 and 1.25 ± 0.78 mm, respectively, for the displacement and filling groups, with a significant difference (p-value = 0.0497). Conclusion: Results showed a significant and effective bone gain around dental implants at a 3-year survey for both sinus augmented by backward displacement of the anterior wall (+34%) and sinus lifting and grafting with a lateral window approach (+57%).

A retrospective study of implants placed following 1-stage or 2-stage maxillary sinus floor augmentation by the lateral window technique performed on residual bone of <4 mm: Results up to 10 years of follow-up

BACKGROUND

The purpose of this study was to compare the survival rates of implants placed following 1-stage or 2-stage maxillary sinus floor augmentation by the lateral window technique (SFALW) performed on residual bone of <4 mm.

METHODS

This study was conducted based on dental records and radiographs obtained from patients who received SFALW from March 2006 to June 2014, being followed up between March 2006 and December 2017. They were divided into 1-stage and 2-stage groups according to the SFALW performed. Statistical analysis was performed to evaluate whether a significant difference existed between 1-stage and 2-stage SFALW in terms of survival rates. Multivariable logistic regression analysis was used to examine the influence of multiple variables on implant failure.

RESULTS

A total of 395 implants (156 implants in the 1-stage group, 239 implants in the 2-stage group) in 167 patients fulfilled the inclusion criteria. Among them, 13 implants (five implants in the 1-stage group, eight implants in the 2-stage group) failed. No significant difference was found in the 10-year cumulative survival rate of implants between the 1-stage group and the 2-stage group (96.8% and 92.5%, respectively, P = 0.656). Multivariable logistic regression analysis demonstrated that implant failure was significantly influenced by implant length and functional time following prosthetic loading.

CONCLUSIONS

The 10-year cumulative survival rates showed no statistically significant difference between implants following 1-stage and 2-stage maxillary SFALW performed on residual bone height of <4 mm.

The use of mineralized bone allograft as a single grafting material in maxillary sinus lifting with severely atrophied alveolar ridge (1-3 mm) and immediately inserted dental implants. A 3- up to 8-year retrospective study

OBJECTIVE

The primary aim of our study was to evaluate the efficacy of mineralized bone allograft alone in sinus floor augmentation with simultaneous implant placement in cases with severe atrophy of the residual maxillary bone (bone height < 4 mm).

METHODS

Thirty-five dental implants were placed in 29 patients who underwent sinus augmentation via traditional lateral window technique from 2008 to 2013. Patients with residual alveolar height between 1 and 3 mm at the site of implantation were included in the study. The height of residual bone was initially estimated by plain panoramic X-ray and reevaluated intraoperatively by precise micrometric measurement at the site of implantation. Implants of 13 mm height and 3.5 or 4.3 mm in diameter were inserted simultaneously. Mineralized bone allograft was used alone to augment the sinus floor.

RESULTS

No wound dehiscence was recorded. In one case there was a postoperative site infection which subsided with antibiotics without implant failure. One implant migrated during the postoperative period to the maxillary sinus and was removed. One implant failed. The remaining 33 implants were successfully loaded. Follow-up ranged from 3 to 8 years.

CONCLUSIONS

Maxillary sinus lift in severely absorbed alveolar ridges with simultaneous implant placement could be safely performed using mineralized allograft alone, rendering the procedure less invasive and less time-consuming.

Long-Term Implant Survival After 100 Maxillary Sinus Augmentations Using Plasma Rich in Growth Factors

PURPOSE

To identify determinants of long-term implant survival after sinus augmentation procedure (SAP) using a combination of plasma rich in growth factors (PRGF) and graft material.

MATERIALS AND METHODS

Patients were included in this retrospective study if they underwent SAP through a lateral wall approach using PRGF in combination with mainly xenograft, and received implants restored for at least 1 year. Sociodemographic, behavioral and implant characteristics (clinical factors, implant details, surgical details, prosthesis details, and complications) were analyzed.

RESULTS

Sixty-seven patients received 217 implants in 100 augmented sinuses. The mean follow-up was 7.2 years. Overall, 22 implants failed in 15 patients (90% cumulative implant survival). Multivariable models showed greater implant survival with implants placed with ≥5 mm of residual crestal bone height (RBH) compared with those placed with <3 mm of RBH. There was also an improvement in survival comparing implant lengths. In addition, immediate loading of implants significantly increased the risk of implant failure.

CONCLUSION

The use of PRGFs for maxillary sinus grafting may be an effective and safe treatment option for the rehabilitation of atrophic edentulous posterior maxillae. However, randomized clinical trials are needed to confirm these findings.

Subantral Augmentation with a 1/1 Alloplastic and Autologous Material Mixture. Histological Characteristics and Dimensional Stability of the Newly Formed Bone

Background and aim.

The maxillary sinus augmentation procedure is the most frequent method used to prepare the posterior maxillary area, with bone deficit, for the placement of dental implants. For this purpose, several types of materials have been used as bone grafts, each of these materials having a number of advantages and disadvantages. The present study is aimed at evaluating the histological and volumetric properties of an alloplastic and autologous material mixture.

Patients and methods.

The study included 7 selected patients who underwent subantral bone augmentation with a 1/1 autologous and alloplastic material mixture. Subsequently, at the time of dental implant placement, biological samples were taken from the bone augmentation area and were histologically analyzed. The subantral bone resorption rate was also evaluated in parallel.

Results.

Histological examination evidenced the presence of residual amorphous material in the bone augmentation area. The mean bone resorption rate was 15.15%. The presence of a high bone resorption rate was correlated with the presence of a smaller residual amorphous material amount in the subantral bone augmentation area.

Conclusions.

The association of autologous and alloplastic material for subantral bone augmentation improves the characteristics of the two material types.

Angulated implants: an alternative to bone augmentation and sinus lift procedure: systematic review

Rehabilitation of completely edentulous patients with implant becomes challenging due to reduced amount of bone available and pneumatisation of maxillary sinus or both. To successfully treat such patients, prior to implant placement, patient has to undergo invasive procedures like sinus lift and/or bone augmentation which is not possible many time due to many reasons. This article focuses on an alternative treatment procedure in which two posterior implants are placed at an angle and two anterior implants are placed axially thereby eliminating the need for sinus lift or bone augmentation procedures. This article broadly discusses this "All on Four" concept in all aspects, its effects on bone, prosthesis survival, forces acting etc along with various related studies.