Evaluation of Different Approaches for Sinus Membrane Perforation Repair During Sinus Elevation: A Systematic Review and Meta-analysis.

PURPOSE: To evaluate the impact of different approaches to sinus membrane perforation (SMP) repair on bone formation, postoperative complications, and implant loss risk. MATERIALS AND METHODS: Electronic searches on PubMed, Web of Science, Scopus, Embase, and Cochrane Library databases were conducted for publications up to February 2021. All included articles reported SMPs submitted for repair. The proportion of implant loss in repaired SMP sites was calculated using a random-effects model meta-analysis. RESULTS: A total of 130 studies reporting SMP repair protocols were included in the systematic review, with 20 selected for meta-analysis. A total of 1,972 sinuses that were perforated and repaired during sinus elevation using different approaches were included in the qualitative analysis. The resorbable collagen membrane was the most commonly reported treatment. The presence of sinusitis was the most frequently described complication. Regarding bone parameters, the majority of studies described no differences between perforated and repaired sinuses and intact membranes. No difference in the implant loss proportion was observed between sites with repaired SMP compared to undetected SMP. The proportion of implant loss in repaired sinuses membrane sites (independent of the material or implant placement time) was 4% (95% CI: 2.0 to 8.0). In meta-regression analysis, no association was observed between the SMP size and implant loss proportion (P = .86). CONCLUSIONS: The materials and techniques indicated for SMP management seem to securely seal the maxillary sinus, without a negative effect on the ultimate survival of the implants placed in the affected sinuses.

Supraphysiologic Testosterone Administration Impairs Late Osseointegration in Male Rats.

PURPOSE: To evaluate the effect of supraphysiologic administration of testosterone in an early and late model of implant osseointegration in rat tibiae. MATERIALS AND METHODS: A total of 40 rats were randomly allocated into four groups (n = 10/ group), which were divided according to the type of experiment and time of osseointegration: (1) vehicle (14 days), (2) testosterone (14 days), (3) vehicle (42 days), and (4) testosterone (42 days). Testosterone cypionate (7.5 mg/kg) administration started 4 weeks before implant placement, and the injections were performed daily until euthanasia. Machined-surface titanium implants (2.2 mm in diameter and 4 mm high) were placed bilaterally in the tibia of animals 28 days after the first testosterone injection. At days 14 and 42 after implant placement, euthanasia was performed and the tibiae were harvested to perform biomechanical evaluation and histomorphometric analysis of bone-to-implant contact (BIC%) and bone between the threads (BBT%). RESULTS: There was no statistical difference in the removal torque of the implants between the groups treated with the vehicle (control group) or testosterone (P > .05). At 14 days of osseointegration, the BIC% and BBT% did not differ between vehicle or testosterone groups (P > .05), while at 42 days, both the BIC% and BBT% were significantly reduced by testosterone compared to the vehicle group (P < .05). CONCLUSIONS: Testosterone cypionate in supraphysiologic dose impaired late-phase osseointegration in rat tibiae.

Assessing bone formation on hydrophilic and hydrophobic implant surfaces in a murine model treated with bisphosphonates.

OBJECTIVE: To evaluate the osseointegration of implants with hydrophobic (HFB) and hydrophilic (HFL) surfaces in a murine model of high-dose bisphosphonates (BPs). MATERIALS AND METHODS: Sixty-four rats were randomly allocated into four groups: control group with HFB implants (CG-HFB), control group with HFL implants (CG-HFL), BP group with HFB implants (BP-HFB), and BP group with HFL implants (BP-HFL). Animals were euthanized after 15 and 45 days (n=8). The dependent variables assessed were the removal torque (biomechanical analysis), the bone volume around the implants (%BV/TV) (microtomographic analysis), the bone-implant contact (%BIC), the bone between the threads (%BBT) (histomorphometric analysis), and the expression of bone metabolism markers (immunohistochemistry analysis). RESULTS: The CG-HFL and BP-HFL groups presented higher removal torque than the CG-HFB and BP-HFB implants. The %BIC of the CG-HFL surfaces was slightly higher than that of the CG-HFB implants. The BP-HFB and BP-HFL groups presented a higher %BIC than that of the CG-HFB and CG-HFL groups (p<0.001). BP therapy also increased the %BBT at both implant surfaces. Higher levels of ALP were observed in the matrix region of bone tissue on the HFL surfaces than on the HFB surfaces. CONCLUSION: Both surfaces enable osseointegration in rats under BP therapy. CLINICAL RELEVANCE: The study demonstrates that hydrophobic (HFB) and hydrophilic (HFL) implant surfaces can promote osseointegration in rats undergoing bisphosphonate therapy. The HFL surfaces exhibited improved biomechanical performance, higher bone-implant contact, and increased bone volume, suggesting their potential clinical relevance for implant success in individuals on bisphosphonate treatment.

Influence of obesity on osseointegration of implants with different surface treatments: A preclinical study.

OBJECTIVE: The aim of the present study was to evaluate the effect of obesity on the osseointegration of implants with hydrophobic and hydrophilic surfaces. MATERIALS AND METHODS: Sixty-four male rats were distributed among four experimental groups: H-HB (Healthy/Hydrophobic): healthy animals with hydrophobic implants; H-HL (Healthy/Hydrophilic): healthy animals with hydrophilic implants; O-HB (Obese/Hydrophobic): animals with induced obesity and hydrophobic implants; O-HL (Obese/Hydrophilic): animals with induced obesity and hydrophilic implants. One hundred and twenty-eight implants were installed in the tibiae of the animals bilaterally (64 on the left tibiae and 64 on the right one) after 75 days of a specific diet (standard or high-fat diet) and euthanasia was performed in the experimental periods of 15 and 45 days after implant placement. Bone formation was assessed by biomechanical analysis (on the left tibiae of each animal), and microtomographic and histomorphometric analyses (on the right tibiae of each animal). Statistical analysis was performed using the Shapiro-Wilk test for normality and ANOVA followed by Tukey test to observe whether there was a significant difference between groups (p < 0.05); the t-test was used to compare the animals' body weight. RESULTS: The biomechanical analysis showed an increase in the removal torque value of animals after 45 days in comparison to after 15 days, with the exception of O-HB groups. The microtomographic analysis demonstrated no significant differences in the mineralized bone tissue volume between the groups. In the histomorphometric analysis, the H-HL/45 day group/period demonstrated higher bone-implant contact, in comparison to H-HL/15 days and the O-HL/45 day group/period showed an increase in bone area between the implant threads, in comparison to O-HL/15 days. CONCLUSION: In conclusion, obesity does not interfere with the osseointegration of hydrophobic and hydrophilic implants.

The use of 3D ceramic block graft compared with autogenous block graft for rehabilitation of the atrophic maxilla: a randomized controlled clinical trial.

BACKGROUND: Dental implant placement may require a bone graft for vertical and horizontal alveolar ridge augmentation. Due to its osteoconduction, osteoinductive, and osteogenesis, autogenous bone graft characteristics are considered the standard gold treatment. However, autografts can promote postoperative morbidity and implicate difficulties concerning the graft adaptation to the recipient's bone since it can eventually avoid gaps. To overcome these issues, this trial will compare the performance of Plenum® Oss 3Dß fit, an alloplastic graft, and a 3D-printed patient-specific graft based on ß-tricalcium phosphate to the autograft procedure. METHODS: This is a split-mouth randomized clinical study designed to evaluate the performance of personalized (patient-specific) bioceramic bone grafts (Plenum® Oss 3Dß fit) for bone augmentation of the atrophic anterior maxilla in comparison to the autogenous bone graft. We hypothesize that the gain and maintenance of the grafted area volume and the quality of the newly formed bone tissue after eight months postoperative with the synthetic patient-specific graft will be superior to the autogenous bone graft. To assess the quantity and the quality of bone neoformation, volumetric and histological analyses will be performed. DISCUSSION: The fabrication of medical devices by additive manufacturing presents advantages over conventional manufacturing processes, mostly related to the precision of geometry and anatomy. Additionally, the osteoconductive proprieties of ß-tricalcium phosphate enable this synthetic bone substitute as an alternative solution over autogenous graft for bone defect reconstruction. Thus, patient-specific bone grafts can potentially improve patient satisfaction, reducing the need for autogenous bone grafts, consequently avoiding implications related to this type of treatment, such as patient morbidity. TRIAL REGISTRATION: This study is registered in REBEC (Registro Brasileiro de Ensaios Clínicos): RBR-76wmm3q; UTN: U1111-1272-7773. Registration date: 14 September 2021.

Evaluation of Implants with Different Macrostructures in Type I Bone-Pre-Clinical Study in Rabbits.

The objective of this study was to assess the primary stability and the osseointegration process in implants with different macrostructures (Cylindrical vs. Hybrid Conical) in rabbit tibiae. Twenty-four (24) rabbits were used, divided into 3 experimental periods (2, 4 and 8 weeks) with 8 animals each. Each animal bilaterally received 2 implants from each group in the tibial metaphysis: Cylindrical Implant (CI) and Hybrid Conical Implant (HCI). All implants were assessed for insertion torque. After the experimental periods, one of the implants in each group was submitted to the removal counter-torque test and descriptive histological analysis while the other implant was used for microtomographic and histometric analysis (%Bone-Implant Contact). HCI implants showed higher insertion torque (32.93 ± 10.61 Ncm vs. 27.99 ± 7.80 Ncm) and higher % of bone-implant contact in the 8-week period (79.08 ± 11.31% vs. 59.72 ± 11.29%) than CI implants. However, CI implants showed higher values of removal counter-torque than HCI implants in the 8-week period (91.05 ± 9.32 Ncm vs. 68.62 ± 13.70 Ncm). There were no differences between groups regarding microtomographic data. It can be concluded that HCI implants showed greater insertion torque and bone-implant contact in relation to CI implants in the period of 8 weeks when installed in cortical bone of rabbits.

Use of alveolar distraction osteogenesis for anterior maxillary defect reconstruction.

Alveolar osteogenic distraction (AOD) is a biological process through which new bone formation occurs between bone segments that are gradually separated by incremental traction. This case report described the oral rehabilitation with dental implants of a patient with a vertical bone defect in the maxillary anterior region using the AOD technique. The patient presented with absence of the teeth 22, 21, 11, and 12 associated with a vertical bone defect. The AOD was performed using a supported osteodistractor device surgically installed with subsequent daily activations. After 21 days, the ideal positioning of bone fragment was confirmed and activation was ceased. Five months after the initial surgery, two dental implants were installed in the region of teeth 12 and 22. An FP3 metal-ceramic prosthesis was installed offering satisfactory esthetic results. In conclusion, the use of AOD to increase the alveolar ridge was effective and ensured rehabilitation with dental implants.

Comparison of the Primary and Secondary Stability of Implants with Anodized Surfaces and Implants Treated by Acids: A Split-Mouth Randomized Controlled Clinical Trial.

PURPOSE: The objective of this randomized controlled clinical split-mouth trial was to compare anodized implant surfaces and implant surfaces modified by acid etching in terms of primary and secondary stability. MATERIALS AND METHODS: Forty-six implants were placed bilaterally in the posterior mandibles of 23 patients. Each patient received one implant with a surface treated by acid (AC) and the other with an anodized implant surface (ANO). The selection of the side where the implant was placed was chosen randomly by lot. The implants were evaluated with respect to insertion torque within the surgical bed and primary and secondary stability by testing the implant stability quotient (ISQ) at five different times (immediate postoperative period and 21, 30, 60, and 180 days after surgery). The paired t test was used to compare the two groups, and ANOVA Repeated Measures complemented by the Tukey posttest were used for longitudinal analysis of the implants in each group. All tests were applied with a confidence level of 95% (P < .05). RESULTS: No statistically significant difference was detected between the AC and ANO groups regarding insertion torque. ISQ analysis revealed that the AC group showed statistically higher values than the ANO group at the 21-day period (P < .05); however, no other statistically significant differences were detected at the other times. CONCLUSION: The different surfaces were similar in terms of primary and secondary stability of implants placed in the posterior mandible.

Effect of Er,Cr:YSGG laser application in the treatment of experimental periodontitis.

The purpose of this study was to evaluate the influence of an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in the absence or presence of manual scaling and root planning (SRP) for the treatment of induced periodontitis in rats. Ligatures were placed in the subgingival region of the maxillary first molar. After a 7-day period, the ligatures were removed, and 40 rats were randomly divided into four groups (G), as follows: (GI) no treatment, (GII) scaling and root planning (SRP) with curettes, (GIII) Er,Cr:YSGG laser irradiation and (GIV) SRP with curettes followed by Er,Cr:YSGG laser irradiation. Seven and 30 days after the treatment, the animals were sacrificed and histologic, histometric and immunohistochemistry analyses were performed. All groups showed similar histopathological characteristics during the evaluation period. The histometric analysis was confirmed using Bonferroni and paired t tests. At 7 and 30 days, groups II, III and IV exhibited greater bone formation in the furcation area when compared to group I (p < 0.0001; p < 0.05). During the 7-day period, the groups irradiated with the laser (III and IV) showed a statistically larger new bone area than the group treated with SRP (II) (p < 0.01). Immunohistochemistry analysis revealed that the control group exhibited a higher expression of tartrate-resistant acid phosphatase (TRAP) and the receptor activator of nuclear factor κΒ ligand (RANKL) when compared to groups II, III and IV (p < 0.05). All treatments were able to reduce the inflammatory processes, consequently enabling the repair of periodontal tissues. The results achieved with the application of the Er,Cr:YSGG laser suggest that this laser can stimulate greater bone formation, especially over a shorter period of time.

Epidemiological aspects of rheumatoid arthritis patients affected by oral bisphosphonate-related osteonecrosis of the jaws.

This literature review aims to evaluate the epidemiologic profile of patients with rheumatoid arthritis (RA) that developed a bisphosphonate-related osteonecrosis that affect the jaws (BRONJ), including demographic aspects, as well as clinical and therapeutic issues. A search of PUBMED/MEDLINE, Scopus, and Cochrane databases from January 2003 to September 2011 was conducted with the objective of identifying publications that contained case reports regarding oral BRONJ in RA patients. Patients with RA who develop oral BRONJ are usually women above 60 years taking steroids and long-term alendronate. Most of them have osteoporosis, and lesions, triggered by dental procedures, are usually detected at stage II in the mandible. Although there is no accepted treatment protocol, these patients seem to have better outcomes with conservative approaches that include antibiotic therapy, chlorhexidine, and drug discontinuation.

Influence of implant connection type on the biomechanical environment of immediately placed implants - CT-based nonlinear, three-dimensional finite element analysis.

PURPOSE: The purpose of the present study was to evaluate the biomechanical environment of immediately placed implants, before and after osseointegration, by comparing three different implant-abutment connection types. MATERIALS AND METHODS: A computer tomography-based finite element model of an upper central incisor extraction socket was constructed containing implants with either external hex, internal hex, or Morse-taper connection. Frictional contact elements were used in the bone, implant, abutment, and abutment screw interfaces in the immediately placed simulations. In osseointegrated simulations, the repair of bone alveolar defect and a glued bone-to-implant interface were assumed. By analysis of variance, the influence was assessed of connection type, clinical situation, and loading magnitude on the peak equivalent strain in the bone, peak von Mises stress in the abutment screw, bone-to-implant relative displacement, and abutment gap. RESULTS: The loading magnitudes had a significant contribution, regardless of the assessed variable. However, the critical clinical situation of an immediately placed implant itself was the main factor affecting the peak equivalent strain in the bone and bone-to-implant displacement. The largest influence of the connection type in this protocol was seen on the peak equivalent stress in the abutment screw. On the other hand, a higher influence of the various connection types on bone stress/strain could be noted in osseointegrated simulations. CONCLUSIONS: The implant-abutment connection design did not significantly influence the biomechanical environment of immediately placed implants. Avoiding implant overloading and ensuring a sufficient initial intraosseous stability are the most relevant parameters for the promotion of a safe biomechanical environment in this protocol.