Can Implant-Retained Fixed Prostheses Trigger Bone Response in the Posterior Region of Edentulous Mandibles? A 32-Month Cone-Beam Computerized Tomography Study Analyzing Bone Height and Density.

Research has shown that the presence of implants can revert bone resorption and thus contribute to a greater preservation of the residual bone ridge, especially in edentulous mandibles. Bone remodeling has yet to be extensively studied in the context of prosthetic options for edentulous arches. This study aims to evaluate the long-term behavior of bone tissue in the posterior region of edentulous mandibles rehabilitated with implant-retained fixed prostheses using cone-beam computerized tomography (CBCT). Selected individuals were rehabilitated with 5 external hexagon platform implants and an implant-retained fixed prosthesis. The CBCT scans were performed immediately after surgery and after 8, 22, and 32 months (T0, T8, T22, and T32, respectively). Implants were installed between the mental foramen. Subsequently, bone crest height and density were measured in the posterior region of the mandible on the images in 3 distinct areas at 5, 10, and 15 mm from the center of the distal implant axis. Analysis of variance and the Bonferroni post hoc test were used for multiple analyses. The results indicate a statistically significant difference in bone height between T0 and all subsequent times; the bone height at T32 was 8.85% higher than at T0 (P = .05). There was a difference in bone height between all analyzed regions. The bone growth difference between the 5-mm and 15-mm positions was 28.42% after 32 months (P = .00). A significant increase of 5.76% in bone density was observed between T0 and T22 (P = .03). Within the limitations of this study (sample size, follow-up duration), it was demonstrated that the use of implant-retained fixed prostheses in the mandible resulted in qualitative and quantitative bone growth (bone preservation) in the posterior region of the mandible. Further research is needed to identify the validity of our findings for other populations and to determine the duration of the bone-remodeling process in rehabilitated edentulous mandibles.

RANK/RANKL/OPG gene polymorphisms and loss of orthodontic mini-implants.

OBJECTIVE: To investigate the association of genetic polymorphisms (tagSNPs type) of RANK/RANKL/OPG genes with the loss of orthodontic mini-implants (MIs). SETTING AND SAMPLE POPULATION: One hundred and thirty-five patients of both sexes, with mean age of 48.7 ± 10 (20-76 years), were studied. The control group was composed of 104 patients, with no MI lost and functioning for at least 6 months and the case group, of 31 patients with at least one MI lost. MATERIALS AND METHODS: Cells were obtained by mouthwash with 3% glucose solution for 1 minute and scraping the buccal mucosa with sterilized spatula. DNA was extracted from buccal epithelial cells with 10 M ammonium acetate and 1 mM EDTA. Genotyping was performed by the real-time polymerase chain reaction (PCR) technique. Univariate and multivariate analyses were performed (P < .05). RESULTS: No markers were associated with MI loss after Benjamini and Hochberg false discovery rate correction of Univariate tests. In the multivariate analysis, the variables that associated with MI loss were the number of MIs installed (P < .000) and the polymorphism rs8086340 in the RANK gene (P = .018). CONCLUSION: A higher number of MIs installed (P < .000) and polymorphism rs8086340 in the RANK gene (P = .018) were associated with loss of orthodontic MIs after multivariate analysis.

Influence of facial patterns on the masticatory function and quality of life of completely edentulous patients during the transition to implant-retained mandibular overdentures.

STATEMENT OF PROBLEM: Although implant-retained mandibular overdentures (IMOs) provide functional benefits, the influence of the vertical facial pattern (FP) and the anteroposterior skeletal discrepancy (ASD) on the masticatory function and patient-centered outcomes during the transition to IMOs is still uncertain. PURPOSE: The purpose of this interventional clinical study was to evaluate the influence of the FP and ASD on the masticatory function, oral health-related quality of life (OHRQoL), and satisfaction of completely edentulous patients before and after transition to IMOs. MATERIAL AND METHODS: Cephalometric analysis was performed on 42 participants before treatment. Ricketts analysis was used to classify the FP, and the maxillomandibular relationship to the base of the skull determined the ASD. Masticatory performance (MP) and swallowing threshold (ST) test results were evaluated by the multiple sieve method by using artificial test food (Optocal cubes) to determine the median particle size (×50), homogenization index (B), and masticatory efficiency based on sieves 5.6 (ME: 5.6) and 2.8 (ME: 2.8). OHRQoL and satisfaction were evaluated by using the Dental Impact on Daily Living questionnaire. The data were analyzed using mixed-effects linear regression models to estimate the effect of time, FP, ASD, age, and sex on MP, ST, and OHRQoL. RESULTS: The MP, ST, OHRQoL, and satisfaction improved significantly after IMO loading, irrespective of FP and ASD. However, MP outcomes were most negatively affected mainly among dolichofacial (B and ME: 2.8), class II, and class III (×50, B, and ME: 2.8) participants. The ST test showed that class II participants still showed inferior ×50 values and performed a lower number of cycles than class I and class III participants. Women presented reduced masticatory function for all MP and ST outcomes and reported lower coefficients for appearance and general performance domains than men. CONCLUSIONS: The MP test detected more subtle improvements than the ST test, especially in class III participants. The class II participants benefited the least from the IMO installation according to the ST test. The IMO treatment improved the OHRQoL and satisfaction of edentulous patients, irrespective of the FP or ASD.

Retrospective, cross-sectional study on immediately loaded implant-supported mandibular fixed complete-arch prostheses fabricated with the passive fit cementation technique.

STATEMENT OF PROBLEM: Mandibular fixed complete-arch dental prostheses on dental implants have been benefiting patients for a long time, but problems with passive fitting between the metallic framework of the prostheses and the implants might influence its long-term success. PURPOSE: The purpose of this cross-sectional study of immediately loaded mandibular fixed complete-arch dental prostheses was to evaluate the survival and success rates of prostheses, the survival rates of dental implants, the occurrence of complications in the prostheses and implants, participant satisfaction, and the association between cantilever length and prosthesis complications. MATERIAL AND METHODS: Data were collected from the participants' records. The exposure variables were participant related (sex and age) and treatment related (number of implants and length of cantilever). The outcome variables were the survival and success of the prostheses and implants, complications, and participant satisfaction. The Fisher or chi-square tests was used for the association between 2 qualitative variables (α=.05). RESULTS: Two hundred ninety consecutive participants (1429 implants) with a mean follow-up time of 4.4 years were included. The survival rate for the prostheses was 98.6 and the success rate was 96.6%. The implant survival rate was 99.6%. Sixty-seven participants experienced a prosthetic complication, the most common being tooth fracture. Only 2.45% (n=35) of the implants were associated with screw loosening. Of the total number of participants, 86.9% were completely satisfied with their treatment. The length of the cantilever (up to 25 mm) was not associated with complications (P>.05). CONCLUSIONS: Implant-supported mandibular fixed complete-arch dental prostheses fabricated with a passive fit technique provide successful treatment for patients with edentulism. The success and survival rates of implants and prostheses were high. Only straightforward complications were observed. Cantilever length was not associated with complications.

Maximum Bite Force of Edentulous Patients before and after Dental Implant Rehabilitation: Long-Term Follow-Up and Facial Type Influence.

PURPOSE: (1) To evaluate patients' long-term maximum bite force (MBF) after rehabilitation with mandibular implant-supported prosthesis, (2) to assess the influence of facial pattern in MBF, and (3) to evaluate the relation between the dominant chewing side and MBF. MATERIALS AND METHODS: Twenty-nine patients were selected. Pre- (T0) and immediate post-rehabilitation (T1) data of MBF were collected. In a follow-up visit 3 to 5 years after rehabilitation (T2), 24 patients participated. The patients were asked about dominant chewing side, and facial pattern was obtained by the initial lateral radiographs. RESULTS: There was statistically significant increase in MBF in T1 - T0 = 5.4 ± 4.3 kgf, T2 - T1 = 5.5 ± 6.0 kgf. There was no statistically significant difference in MBF considering facial type, brachyfacial (T0 = 4.4, T1 = 10.7, T2 = 17.6 kgf), mesofacial (T0 = 4.1, T1 = 9.7, T2 = 16.5 kgf), and dolichofacial (T0 = 3.4, T1 = 7.9, T2 = 12.6 kgf). CONCLUSIONS: There was no statistically significant relation between MBF and the dominant chewing side. It can be concluded that mandibular rehabilitation with dental implants improves MBF independent of the facial pattern and dominant chewing side.

Morse Taper Implants Immediately Loaded in Fresh Extraction Sockets: A Prospective Cohort Study.

PURPOSE: To evaluate survival rate and bone response around immediate loaded Morse taper implants installed in fresh sockets on the anterior area of the maxilla. MATERIAL AND METHODS: The sample comprised 16 patients in whom 16 single implants were installed. All the teeth were extracted in a flapless surgery. Radiographic and tomographic evaluations were performed immediately after surgery (T1) and after 12 months (T2). The variables studied were height of the buccal wall (HBW), buccal wall width (BW) at 3 levels, and proximal bone height at 2 different areas: the alveolar crest level (CLH) and at the point where bone tissue meets the implant surface (BIS). RESULTS: Statistically significant differences were observed. The buccal plate showed bone loss in height (HBW = -0.50 ± 0.42 mm) and in width (BW-1 = -0.71 ± 0.48 mm; BW-2 = -0.48 ± 0.34 mm; BW-3 = -0.48 ± 0.34 mm). In the proximal areas, there was also bone loss in height (CLH-M = -0.85 ± 0.89 mm; BIS-M = -0.91 ± 0.70 mm; CLH-D = -0.64 ± 0.57 mm; and BIS-D = -0.68 ± 0.62 mm). CONCLUSION: There was 100% survival rate after a 12-month period, but bone loss was observed in all evaluated areas.

Immediate Loading of Edentulous Mandible With Prefabricated Bars: A Long-Term Study of 7 Years.

PURPOSE: To present clinical data from a 7-year follow-up study of edentulous mandibles rehabilitated according to an immediate loading protocol with prefabricated bars. MATERIALS AND METHODS: Forty-four implants were inserted in 11 patients and were evaluated by means of resonance frequency analysis (RFA) and clinical and radiographic examination. RESULTS: Ten patients returned for the 7-year evaluation and presented no implant loss. The stability measurements were performed immediately after implant placement (T0 = 64.5 ± 6.6 ISQ) and 1 year (T1 = mean 66.8 ± 4.2 ISQ), and 7 years (T7 = mean 62.8 ± 5.4) after being in function. The analysis of the RFA values showed a statistically significant decrease in implant stability after 7 years in function, although the final values are considered adequate for treatment success. Panoramic x-ray examination showed bone loss greater than the first thread in 10 implants. CONCLUSION: According to the obtained data, it can be concluded that immediate loading according to this protocol with prefabricated bars is a valid treatment option for edentulous patients providing sufficient long-term success.

Bone behavior in atrophic edentulous mandibles after rehabilitation with immediate loaded implant: a short-term radiographic and tomographic study.

PURPOSE: To evaluate bone response in the posterior area of edentulous mandibles rehabilitated with fixed prosthesis supported on dental implants considering baseline severity of mandibular atrophy. MATERIAL AND METHODS: The sample included 15 patients in whom 5 implants were inserted between the mental foramens. The prosthesis followed a cantilever extension from 15 to 20 mm. They were divided into 2 groups (severe and moderate) according to the degree of the atrophy presented. Panoramic x-ray and computerized tomography were obtained immediately after rehabilitation (T0) and after 8 months (T8). Linear measurements of the alveolar bone height at the posterior area of the mandible, 5, 10, and 15 mm from the long axis of the most distal implants, were recorded. Density measurements were also achieved at the same sites. RESULTS: A slight bone increase in both groups was observed but with no statistically significant difference according to the baseline degree of atrophy. CONCLUSIONS: There was slight qualitative and quantitative bone improvement in the posterior area of the mandibles with the use of immediately loaded implant-supported fixed prostheses during the observed period. These results suggest that long-term follow-up is very important to understand bone behavior after rehabilitation.

Effects of pilot holes on longitudinal miniscrew stability and bony adaptation.

INTRODUCTION: The purposes of this study were to longitudinally evaluate the effects of pilot holes on miniscrew implant (MSI) stability and to determine whether the effects can be attributed to the quality or the quantity of bone surrounding the MSI. METHODS: Using a randomized split-mouth design in 6 skeletally mature female foxhound-mix dogs, 17 MSIs (1.6 mm outer diameter) placed with pilot holes (1.1 mm) were compared with 17 identical MSIs placed without pilot holes. Implant stability quotient measurements of MSI stability were taken weekly for 7 weeks. Using microcomputed tomography with an isotropic resolution of 6 µm, bone volume fractions were measured for 3 layers of bone (6-24, 24-42, and 42-60 µm) surrounding the MSIs. RESULTS: At placement, the MSIs with pilot holes showed significantly (P <0.05) higher implant stability quotient values than did the MSIs placed without pilot holes (48.3 vs 47.5). Over time, the implant stability quotient values decreased significantly more for the MSIs placed with pilot holes than for those placed without pilot holes. After 7 weeks, the most coronal aspect of the 6- to 24-µm layer of cortical bone and the most coronal aspects of all 3 layers of trabecular bone showed significantly larger bone volume fractions for the MSIs placed without pilot holes than for those placed with pilot holes. CONCLUSIONS: MSIs placed with pilot holes show greater primary stability, but greater decreases in stability over time, due primarily to having less trabecular bone surrounding them.

Local application of zoledronate enhances miniscrew implant stability in dogs.

INTRODUCTION: The primary purposes of this study were to evaluate how locally delivered zoledronate affects the longitudinal stability of miniscrew implants (MSIs) and the healing of bone around MSIs. METHODS: Using a randomized split-mouth design, 60 unloaded MSIs (5 × 1.6 mm) were placed in skeletally mature male foxhound-mixed breed dogs. The MSIs were randomly assigned to bilateral pairs of pilot holes (1.1 mm) that had been injected with either bisphosphonate zoledronate (n = 30, experimental group) or buffered saline solution (n = 30, control group). MSI stability was evaluated weekly for 8 weeks using resonance frequency analyses (Osstell Mentor; Integration Diagnostics, Göteborg, Sweden). Microcomputed tomography (6-µm voxel size) was used to determine the bone volume fractions of 3 layers of bone (6-24, 24-42, and 42-60 µm) surrounding the MSIs. RESULTS: Resonance frequency analysis showed that the control MSIs were significantly (P <0.05) less stable than the experimental MSIs. Although there was little or no change in stability over time for the MSIs treated with zoledronate, the stability of the control MSIs decreased during the first 4 weeks, increased through week 6, and then decreased again. The 6- to 24-µm layer closest to the MSIs, on both the experimental and the control sides, showed significantly (P <0.05) less bone than did the 24- to 42-µm and the 42- to 60-µm layers. After 8 weeks, there was significantly more cortical bone surrounding the control than the experimental MSIs. In contrast, there was significantly more trabecular bone surrounding the experimental than the control MSIs. CONCLUSIONS: One small locally delivered dose of zoledronate maintained the stability of MSIs over time, primarily because of greater amounts of trabecular bone surrounding the MSIs. Even though zoledronate enhanced the stability of MSIs in dogs, it should not be used clinically until further studies confirm its safe use in patients.

Benefits of rehabilitation with implants in masticatory function: is patient perception of change in accordance with the real improvement?

This study aimed to compare the index of satisfaction and masticatory function of edentulous patients before and after rehabilitation and to evaluate if patients' perception of the changes in their oral health status is in agreement with the results of masticatory performance test. Fourteen edentulous patients were rehabilitated with lower implant-supported fixed prosthesis and upper removable dentures. Index of satisfaction and masticatory capacity (subjective analysis) and performance test (objective analysis) were evaluated before and 20 days and 8 months after rehabilitation. The patients were asked to respond a yes/no masticatory capacity questionnaire and to rate their oral satisfaction on a 0 to 10 Visual Analogue Scale (VAS). Masticatory performance test comprised the ability of the individual to pulverize an artificial test food (Optocal), after 20 and 40 masticatory strokes. When baseline answers were compared to answers 8 months after treatment, all questions, excepting the ones that considered pain and social disability, were statistically different. Wilcoxon test was used to compare index of satisfaction before and after treatment. All answers showed statistically significant differences, excluding the one that referred to ease of cleaning the prostheses. Considering the masticatory performance test, Student t test (normally distributed) and Wilcoxon test (non-normally distributed) were used to test the null hypothesis that the weight of the particles of the test food left in sieves were equal in all times of evaluation. In the larger sieve with 20 cycles, statistically significant differences were observed between baseline and 8 months, 20 days and 8 months. With 40 strokes, baseline and 20 days, baseline and 8 months and 20 days and 8 months showed significant differences. It was concluded that oral rehabilitation leads to better masticatory function in edentulous patients and there is a coincidence between patient perception and real improvement on masticatory function.

Attachment-retained gingival prosthesis for implant-supported fixed dental prosthesis in the maxilla: a clinical report.

The rehabilitation of edentulous maxillae is a complex procedure due to the involvement of esthetic and functional requirements. A trial maxillary denture can be used to identify the need for adequate upper lip support when replacing removable complete dentures by implant-fixed dental prostheses. This clinical report describes the outcome of the rehabilitation of an edentulous atrophic maxilla with unfavorable maxillomandibular relationship and deficient upper lip support. A trial denture was fabricated and used to diagnose the need for a prosthesis capable of restoring the upper lip support. The reduced upper lip support was also confirmed by a lateral cephalogram. The patient was rehabilitated by an implant-fixed dental prosthesis associated with an attachment-retained gingival prosthesis. The case presented shows that when loss of upper lip support is detected and the patient does not wish to undergo further surgical reconstruction procedure, the retention of a gingival prosthesis using a ball attachment is a satisfactory treatment option.

Lower molar uprighting with miniscrew anchorage: direct and indirect anchorage.

Lower molar uprighting has been increasingly indicated in clinical orthodontics, mainly because of adult patients with rehabilitation needs. The aim of this study was to determine the success rate of miniscrew use for lower molar uprighting and to compare the use of direct and indirect anchorage. One hundred and eighty-one miniscrews were inserted in 102 rehabilitation patients, with a mean age of 42.24 years. In 71 patients, indirect anchorage was used (116 miniscrews); in the other 31 patients, direct anchorage was employed (65 miniscrews). The choice of direct or indirect anchorage was determined by the orthodontist according to the force system that would be used for the movement and the bone availability. The overall success rate for miniscrews was 90. 05%; 18 miniscrews failed, including 15 that were used as indirect anchorage and 3 that were used as direct anchorage. Considering the results of this study, it can be concluded that both direct and indirect anchorage can be successfully used for molar uprighting.

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.

A prospective follow-up study of 44 mandibular immediately loaded implants using resonance frequency analysis: preliminary 1-year results.

PURPOSE: This clinical study aimed to evaluate initial, 4-months, and 1-year stability of immediately loaded dental implants inserted according to a protocol of lower rehabilitation with prefabricated bars. MATERIALS AND METHODS: The sample was composed of 11 edentulous patients. In each patient, 4 interforaminal implants were inserted. Immediately after implant installation, resonance frequency analysis (RFA) for each fixation was registered as well as after 4 months and 1 year with the prosthetic bar removed as it is a screwed system. RESULTS: The clinical implant survival rate was 100%. The RFA showed an increase in stability after 4 months from 64.09 +/- 6.48 to 64.31 +/- 4.96 and 1 year, 67.11 +/- 4.37. The analysis of variance showed a statistically significant result (P = 0.015) among implant stability quotient values for the different periods evaluated. Tukey test results showed statistically significant differences between 1-year results and the initial periods but there was no statistically significant difference between initial and 4-month results (P > 0.05). CONCLUSION: These preliminary 1-year results indicate that immediate loading of mandibular dental implants using the studied prefabricated bars protocol is a reliable treatment as it is in accordance with the results described in the literature for other similar techniques.

Bone response after immediate placement of implants in the anterior maxilla: a systematic review.

PURPOSE: The objective of this systematic review was to assess the three-dimensional changes in bone tissue after immediate installation of a single implant in a fresh extraction socket in the anterior maxilla. METHODS: After defining a strategy, an electronic search was carried out using the databases PubMed, Embase, LILACS, Web of Science, Cochrane, and Scopus. In addition, the gray literature was also researched using Google Scholar and ProQuest. Two reviewers independently screened for eligible studies, assessed the methodological quality, and extracted the data. The inclusion criteria were observational studies and experimental studies that assessed bone response after the immediate installation of a single implant in a fresh extraction socket, immediately loaded or not, in the region between the maxillary canines. Studies were included in any language, with no publication date restrictions and with a minimum of 6 months of follow-up after the surgical procedure. RESULTS: From a total of 3272 articles, only 12 studies met the inclusion criteria and were selected for the review. Bone remodeling after immediate installation of a dental implant was assessed using standardized periapical radiographs and cone beam computed tomography (CBCT). CONCLUSION: It can be concluded that bone remodeling occurs after tooth extraction and immediate implant installation.

Upper molar intrusion in rehabilitation patients with the aid of microscrews.

BACKGROUND: Overeruption of an upper molar following loss of the opposing tooth is a common clinical finding. Rehabilitation can be difficult when the interocclusal space is reduced. AIM: To intrude an overerupted upper first molar and replace the missing lower first molar. METHODS: Buccal and palatal microscrews and a transpalatal bar were placed. The palatal miniscrew loosened shortly after implantation and was not replaced. A short length of elastomeric chain from the buccal miniscrew applied 30 g of force to the overerupted molar. The elastomeric chain was replaced every four weeks. RESULTS: Sufficient intrusion of the upper molar was obtained in 4 months. CONCLUSION: A single buccal microscrew and transpalatal arch can be used to intrude an overerupted upper molar.

Assessing the effects of hydrogen peroxide bleaching agent on the shear bond strength of orthodontic brackets.

BACKGROUND: Tooth bleaching is, today, one of the most widespread cosmetic treatments in dental practice,  so it is important to determine whether it can interfere with orthodontic bonding or not. AIM: The aim of this study was to assess the in vitro effects of 35% hydrogen peroxide bleaching agent on the shear bond strength of orthodontic brackets. MATERIALS AND METHODS: Forty-five upper bicuspids were divided into three groups (n = 15). In the control Group (C), the brackets were bonded without previous bleaching treatment. Group 1 (G1) was treated with 35% hydrogen peroxide bleaching agent 24 h before bracket bonding. Group 2 was also bleached, and the brackets were bonded after 30 days. The shear bond strength of the brackets was measured using an EMIC machine, and the results were analyzed by ANOVA. RESULTS: There were no statistically significant differences between the three groups (P > 0.05), with Group C showing a mean bond strength of 9.72 ± 2.63 MPa, G1 of 8.09 ± 2.63 MPa, and G2 of 11.15 ± 4.42 MPa. CONCLUSION: It was possible to conclude that 35% hydrogen peroxide bleaching agent does not affect the shear strength of orthodontic brackets bonded 24 h and 30 days after bleaching.

Simplifying the Treatment of Bone Atrophy in the Posterior Regions: Combination of Zygomatic and Wide-Short Implants-A Case Report with 2 Years of Follow-Up.

The rehabilitation of maxillary and mandibular bone atrophy represents one of the main challenges of modern oral implantology because it requires a variety of procedures, which not only differ technically, but also differ in their results. In the face of limitations such as deficiencies in the height and thickness of the alveolar structure, prosthetic rehabilitation has sought to avoid large bone reconstruction through bone grafting; this clinical behavior has become a treatment system based on evidence from clinical scientific research. In the treatment of atrophic maxilla, the use of zygomatic implants has been safely applied as a result of extreme technical rigor and mastery of this surgical skill. For cases of posterior mandibular atrophy, short implants with a large diameter and a combination of short and long implants have been recommended to improve biomechanical resistance. These surgical alternatives have demonstrated a success rate similar to that of oral rehabilitation with the placing of conventional implants, allowing the adoption of immediate loading protocol, a decrease in morbidity, simplification and speed of the treatment, and cost reduction. This case report presents complete oral rehabilitation in a patient with bilateral bone atrophy in the posterior regions of the maxilla and mandible with the goal of developing and increasing posterior occlusal stability during immediate loading.

Risk factors associated with the failure of miniscrews - A ten-year cross sectional study.

The aims of this study were to identify (1) patient-related factors (sex, age, craniofacial pattern and smoking habit), (2) miniscrews implants (MSI)-related factors (length and diameter) and (3) location-related factors [bone (maxilla or mandible) and area (buccal, lingual and alveolar ridge)] that may be associated with MSI loss of stability. A total of 1356 MSI were installed in 570 patients (423 females and 147 males) with mean age of 42.7 during a 10-year period and were clinically evaluated once a month until the end of the proposed movement. Length (5, 7, 9 and 11 mm) and diameter (1.3, 1.4 and 1.6 mm) of the MSI were selected according to insertion site. The evidence of clinical mobility during treatment or fracture during insertion was considered as failure. A total success rate of 89.1% was observed. There was no statistically significant difference in loss of stability when considering age, sex, craniofacial pattern or smoking habit. Considering diameter, there was no statistically significant difference (p = 0.645), but the shorter miniscrews (5 mm) showed higher failure rates (p < 0.001) than the longer ones. There were more loses (p < 0.001) in the mandible than in the maxilla, but the area (buccal, lingual or alveolar ridge) did not interfere in the results (p = 0,421). It can be concluded that MSIs are effective for skeletal anchorage in orthodontics. Patient-related factors, such as sex, age, smoking habit and craniofacial pattern, did not affect MSI success. However, the use of shorter MSIs (5 mm) was inversely proportional to failure probability, and loss of stability was greater in the mandible.