Biomechanical influence of narrow-diameter implants placed at the crestal and subcrestal level in the maxillary anterior region. A 3D finite element analysis.

PURPOSE: To evaluate the tendency of movement, stress distribution, and microstrain of single-unit crowns in simulated cortical and trabecular bone, implants, and prosthetic components of narrow-diameter implants with different lengths placed at the crestal and subcrestal levels in the maxillary anterior region using 3D finite element analysis (FEA). MATERIALS AND METHODS: Six 3D models were simulated using Invesalius 3.0, Rhinoceros 4.0, and SolidWorks software. Each model simulated the right anterior maxillary region including a Morse taper implant of Ø2.9 mm with different lengths (7, 10, and 13 mm) placed at the crestal and subcrestal level and supporting a cement-retained monolithic single crown in the area of tooth 12. The FEA was performed using ANSYS 19.2. The simulated applied force was 178 N at 0°, 30°, and 60°. The results were analyzed using maps of displacement, von Mises (vM) stress, maximum principal stress, and microstrain. RESULTS: Models with implants at the subcrestal level showed greater displacement. vM stress increased in the implant and prosthetic components when implants were placed at the subcrestal level compared with the crestal level; the length of the implants had a low influence on the stress distribution. Higher stress and strain concentrations were observed in the cortical bone of the subcrestal placement, independent of implant length. Non-axial loading influenced the increased stress and strain in all the evaluated structures. CONCLUSIONS: Narrow-diameter implants positioned at the crestal level showed a more favorable biomechanical behavior for simulated cortical bone, implants, and prosthetic components. Implant length had a smaller influence on stress or strain distribution than the other variables.

Dental caries in HIV-infected children and adolescents: A systematic review with meta-analysis.

This study aimed to evaluate and compare the risk of dental caries in between human immunodeficiency virus (HIV)-infected and uninfected children and adolescents. An electronic search was performed on PubMed/MEDLINE, Web-of-Science, Scopus, LILACS, ProQuest, and ClinicalTrials.gov up to May 2022. The critical appraisal checklist developed by the Joanna Briggs Institute was used to evaluate the quality of the included studies. Meta-analysis was performed using the RevMan 5.4. Sixteen studies were included. A total of 3231 participants were evaluated, including 1701 and 1530 HIV-infected and uninfected children and adolescents, respectively. The meta-analysis revealed a higher risk of dental caries for primary dentitions in HIV-infected children and adolescents by decayed, missing, filled tooth (dmft) (SMD:0.34; p = 0.006) and decayed, missing, filled surface (dmfs) scores (SMD:0.37; p = 0.001). Similar results were observed for permanent dentition, with increased dental caries in HIV-infected children and adolescents with DMFT (SMD:0.32; p = 0.003) and DMFS (SMD:1.78; p < 0.0001) scores. Regarding the quality assessment, most of the included studies were moderate or good quality. However, the certainty of the evidence of the outcomes was very low. This systematic review and meta-analysis showed higher caries severity in permanent and deciduous teeth among HIV-infected children and adolescents.

Associated oral manifestations with HIV southeastern Brazilian patients on antiretroviral therapy

Abstract Objectives This study aimed to assess the prevalence of oral lesions in patients living with HIV infection and their association with CD4 count, viral load, and antiretroviral therapy in patients with HIV. Methods A cross-sectional study was conducted on a sample of 161 patients attending the… All the patients were examined for their oral lesions, current CD4 counts, type, and duration of the therapy. Data analyses were carried out using Chi-Square, Student T/Mann-Whitney, and logistic regression tests. Results Oral lesions were observed in 58.39% of patients with HIV. Periodontal disease with 78 (48.45%) or without mobility 79 (49.07%) was observed more frequently, followed by hyperpigmentation of oral mucosa 23 (14.29%), Linear Gingival Erythema (LGE) 15 (9.32%), candidiasis pseudomembranous 14 (8.70%). Oral Hairy Leukoplakia (OHL) was observed only in 3 (1.86%). A relationship between periodontal disease with dental mobility and smoking was found (p = 0.04), as well duration of treatment (p = 1.53e-3) and age (p = 0.02). Hyperpigmentation was related to race (p = 0.01) and smoking (p = 1.30e-6). CD4 count, CD4:CD8 ratio, viral load, or type of treatment were not associated with oral lesions. Logistic regression showed that the duration of treatment has a protective effect on the periodontal disease with dental mobility (OR = 0.28 [−2.27 to −0.25]; p-value = 0.03), independent of age or smoking. To hyperpigmentation, the best model included smoking (OR = 8.47 [1.18-3.10], p = 1.31e-5), without race or type and duration of treatment. Conclusion Among HIV patients undergoing antiretroviral treatment, oral lesions can be observed, predominantly periodontal disease. Pseudomembranous candidiasis and oral hairy leukoplakia were also observed. No relationship was found between associated oral manifestations in HIV patients and the start of the treatment, TCD4+ and TCD8+ cell count, TCD4:TCD8 ratio, or viral load. The data indicate that there is a protective effect of duration of treatment with relation to periodontal disease with mobility and that hyperpigmentation seems to be more related to smoking than type and duration of treatment. Level of evidence Level 3 (OCEBM Levels of Evidence Working Group*. "The Oxford 2011 Levels of Evidence").

Association between sickle cell disease and periodontal disease: A systematic review.

Previous studies have evaluated the association between sickle cell disease (SCD) and periodontal disease; however, their effect on the periodontal parameters remains unclear. This systematic review aimed to investigate whether individuals with sickle cell disease (SCD) increase the risks of periodontal disease more than those without. For the selection of eligible studies, an electronic search was conducted in the MEDLINE/PubMed, Web of Science, Cochrane Library, and Scopus databases. The meta-analysis was based on the inversion of variance using the mean difference (MD) of the continuous outcomes. The quality assessment of included studies was performed using the JBI Critical Appraisal Tools. In total, 13 studies and 2381 participants were included in the qualitative analysis, while 9 studies were considered for the meta-analysis. The meta-analysis indicated that patients with SCD present similar Plaque Index, Clinical Attachment Level, Bleeding on Probing, and Probing Depth when compared to healthy patients (p > .05). However, the Gingival Index was higher for patients with SCD (p = .0002; MD: 0.20). Compared to healthy patients, patients with SCD did not have an increase in periodontal parameters, except for the gingival index. However, further well-designed studies are recommended to reassess the association between SCD and periodontal diseases.

Do dental implants placed in patients with osteoporosis have higher risks of failure and marginal bone loss compared to those in healthy patients? A systematic review with meta-analysis.

PURPOSE: This systematic review and meta-analysis aimed to compare the dental implant survival rate and marginal bone loss between patients with and without osteoporosis. MATERIALS AND METHODS: This systematic review was registered in PROSPERO (CRD42022356377). A systematic search was performed using five databases: MEDLINE/PubMed, Web of Science, Scopus, Embase, and ProQuest for articles published up to July 2022. Additional searches in ClinicalTrials.gov and the reference lists of included studies were performed. The eligibility criteria comprised observational studies with a direct comparison between patients with and without osteoporosis, with a minimum follow-up of 1 year and 10 implants placed in each group, which consider data analysis based on implant level, without restrictions on period or language of publication. The meta-analysis was performed using RevMan 5.4 program. Risk of bias analysis of the included studies was performed using the Newcastle-Ottawa scale (NOS). RESULTS: Twelve studies met the eligibility criteria, totaling 1132 patients with a mean age range from 54 to 76.6 years. Most of the included patients were women (73.6%). A total of 3505 implants were evaluated-983 in patients with osteoporosis and 2522 in patients without osteoporosis. The meta-analysis indicated no difference in implant survival rates between patients with and without osteoporosis (OR, 1.78; 95% confidence interval [CI], 0.86-3.70; P = 0.12). However, significant bone loss was observed around dental implants placed in patients with osteoporosis (SMD, 0.71 mm; 95% CI, 0.06-0.87 mm). The NOS indicated a low risk of bias in the studies included. However, the certainty of the evidence was classified as very low and low for implant survival rates and bone loss, respectively. CONCLUSION: According to the limitations of the present review, the data suggest that dental implants are a viable treatment option for the rehabilitation of patients with osteoporosis. However, clinical care by professionals is necessary to ensure the maintenance of peri-implant bone stability, as these patients may be susceptible to increased bone loss.

Associated oral manifestations with HIV southeastern Brazilian patients on antiretroviral therapy.

OBJECTIVES: This study aimed to assess the prevalence of oral lesions in patients living with HIV infection and their association with CD4 count, viral load, and antiretroviral therapy in patients with HIV. METHODS: A cross-sectional study was conducted on a sample of 161 patients attending the… All the patients were examined for their oral lesions, current CD4 counts, type, and duration of the therapy. Data analyses were carried out using Chi-Square, Student T/Mann-Whitney, and logistic regression tests. RESULTS: Oral lesions were observed in 58.39% of patients with HIV. Periodontal disease with 78 (48.45%) or without mobility 79 (49.07%) was observed more frequently, followed by hyperpigmentation of oral mucosa 23 (14.29%), Linear Gingival Erythema (LGE) 15 (9.32%), candidiasis pseudomembranous 14 (8.70%). Oral Hairy Leukoplakia (OHL) was observed only in 3 (1.86%). A relationship between periodontal disease with dental mobility and smoking was found (p=0.04), as well duration of treatment (p=1.53e-3) and age (p=0.02). Hyperpigmentation was related to race (p=0.01) and smoking (p=1.30e-6). CD4 count, CD4:CD8 ratio, viral load, or type of treatment were not associated with oral lesions. Logistic regression showed that the duration of treatment has a protective effect on the periodontal disease with dental mobility (OR = 0.28 [-2.27 to -0.25]; p-value=0.03), independent of age or smoking. To hyperpigmentation, the best model included smoking (OR=8.47 [1.18-3.10], p= 1.31e-5), without race or type and duration of treatment. CONCLUSION: Among HIV patients undergoing antiretroviral treatment, oral lesions can be observed, predominantly periodontal disease. Pseudomembranous candidiasis and oral hairy leukoplakia were also observed. No relationship was found between associated oral manifestations in HIV patients and the start of the treatment, TCD4+ and TCD8+ cell count, TCD4:TCD8 ratio, or viral load. The data indicate that there is a protective effect of duration of treatment with relation to periodontal disease with mobility and that hyperpigmentation seems to be more related to smoking than type and duration of treatment. LEVEL OF EVIDENCE: Level 3 (OCEBM Levels of Evidence Working Group*. "The Oxford 2011 Levels of Evidence").

Is the clinical performance of internal conical connection better than internal non-conical connection for implant-supported restorations? A systematic review with meta-analysis of randomized controlled trials.

PURPOSE: To evaluate bone loss, prosthodontics and biological complications, and implant survival rates of internal conical connections (ICC) compared with internal non-conical connection (INCC) implants. METHODS: The systematic review was registered on PROSPERO (CRD42021237170). Meta-analysis was performed using standardized mean difference (SMD) for bone loss and risk ratio (RR) for implant survival and complication rates. Risk of bias analysis was evaluated using RoB 2.0, whereas the GRADE tool was used to evaluate the certainty of evidence. A systematic search of the PubMed, Web of Science, Embase, Cochrane, and ProQuest databases was performed independently by two reviewers for articles published up to March 2022. The search criteria had no language or publication date restrictions. Handsearching analysis was performed in the reference list of potential articles. RESULTS: Twelve randomized clinical trials, including 678 patients and 1006 implants (ICC [n = 476]; INCC [n = 530]), were included. Meta-analysis revealed that ICC demonstrated a lower risk for marginal bone loss (SMD: -0.80 mm; p = 0.004) and prosthodontics complications (RR: 0.16; p = 0.01) than INCC. However, both internal connections demonstrated no significant difference in implant survival rates (RR: 0.54; p = 0.10) and biological complications (RR: 0.90; p = 0.82). The overall risk of bias revealed some concerns and a low risk of bias for most of the included studies. However, the certainty of evidence of outcomes was considered low to moderate. CONCLUSION: ICC may be considered a more favorable treatment option than INCC owing to greater preservation of peri-implant bone tissue and a lower probability of prosthodontics complications. However, well-conducted studies with long-term follow-up are warranted.

Are implant-supported removable partial dentures a suitable treatment for partially edentulous patients? A systematic review and meta-analysis.

STATEMENT OF PROBLEM: A consensus on the clinical performance of implant-supported removable partial dentures (ISRPDs) is lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the clinical performance of ISRPDs in terms of the implant survival rates, marginal bone loss, and patient-reported outcome measures (PROMs). MATERIAL AND METHODS: Four electronic databases (MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane Library) were independently searched by 2 reviewers for articles published up to December 2020. A single-arm meta-analysis was performed to evaluate the implant survival rates and marginal bone loss by using the R program. The Cochrane collaboration tool was used to evaluate the risk of bias of randomized controlled trials (RCTs), and the Newcastle-Ottawa scale for non-RCT studies. RESULTS: Sixteen studies were included, with a total of 334 participants and a mean age of 58 years. The participants received a total of 581 dental implants, 475 conventional and 106 mini-implants. All included studies reported implant survival rate above 90% (range: 92% to 100%). Meta-analysis indicated a high proportion of implant survival rates of 3% (95% confidence interval [CI]: 2% to 5%) and a low mean raw score of marginal bone loss 0.98 mm (CI: 0.61 to 1.36 mm). Compared with conventional RPDs, improved patient quality of life and satisfaction were reported by studies that evaluated ISRPDs. RCT studies exhibited a low risk of bias for most domains, while most non-RCT studies were classified as good quality. CONCLUSIONS: ISRPDs exhibited high implant survival rates and acceptable bone loss with improvement in the quality of life and satisfaction of patients when compared with conventional RPDs. Therefore, they can be considered suitable for the rehabilitation of partially edentulous patients.

Genetic polymorphisms of TNF-α, IL-6, and IL-10 in female elderly patients with chronic temporomandibular disorder pain.

AIM: To verify the association of the TNF-α, IL-6, and IL-10 polymorphisms with chronic temporomandibular disorder pain development in female elderly patients. METHODS: Participants were evaluated according to Diagnostic Criteria for Temporomandibular Disorders. The genomic DNA was extracted from blood according to the Salting Out method followed by a quantification using the NanoDrop spectrophotometer. The -308G/A TNF-α polymorphism analysis was performed by the polymerase chain reaction-restriction fragment length polymorphism technique, the determination of -174G/C IL-6 polymorphism was performed by polymerase chain reaction, and the evaluation of the -1082A/G IL-10 polymorphism was carried out by polymerase chain reaction- allele-specific amplification. Data were analyzed using the BioEstat 5.3 software. RESULTS: The -308G/A TNF-α polymorphism showed a significant difference when genotypes of cases with chronic temporomandibular disorder pain and controls were compared (p = .025). There was a lack of association regarding the -174G/C IL-6 polymorphism (p = .286) however, a positive association between the -1082A/G IL-10 polymorphism with chronic temporomandibular disorder was observed (p = .020). CONCLUSION: The analyzed data of elderly subjects support the possible involvement of the GA genotype of the -308G/A TNF-α and the AA genotype of the -1082A/G IL-10 polymorphisms in the pathogenesis of chronic temporomandibular disorder pain.

Biomechanical analysis of narrow dental implants for maxillary anterior rehabilitation / Análise biomecânica de implantes de diâmetro reduzido para reabilitação da região anterior da maxila

Introdução: O conhecimento da biomecânica de implantes de diâmetro reduzido indica dimensões seguras para uso clínico. Objetivo: O objetivo do presente estudo foi comparar biomecanicamente implantes de diâmetro regular e reduzido para suporte de próteses implantossuportadas unitárias na região anterior da maxila por meio de análise de elementos finitos 3D (3D-FEA). Material e método: Quatro modelos 3D-FEA foram desenvolvidos a partir de recomposição de tomografia computadorizada e dados da literatura: um bloco ósseo na região incisiva lateral superior direita com implante e coroa. M1: 3,75 x 13 mm, M2: 3,75 x 8,5 mm, M3: 2,9 x 13 mm e M4: 2,9 x 8,5 mm. Foi aplicada carga de 178 N nos ângulos 0, 30 e 60 graus em relação ao longo eixo do implante. Foram avaliados mapas de tensão de Von Mises, tensão principal máxima e microdeformação. Resultado: M3 e M4 apresentaram maiores valores de tensão e microdeformação que M1 e M2, principalmente quando foram aplicadas forças inclinadas. Porém, M3 apresentou comportamento biomecânico melhor do que M4. Conclusão: Pode-se concluir que reduzir o diâmetro dos implantes pode prejudicar a biomecânica durante a aplicação de forças, mas a distribuição e intensidade das tensões, bem como os valores de microdeformação podem ser melhorados se o comprimento do implante for aumentado

Introduction: Narrow diameter implants biomechanics knowledge indicates safe dimensions for clinical use. Objective: Purpose of the present study was biomechanically to compare regular and narrow diameter implants to support single implant-supported prosthesis in the anterior region of the maxilla by 3D finite element analysis (3D-FEA). Material and method: Four 3D-FEA models were developed form CT scan recompositing and literature data: a bone block in the right upper lateral incisive region with implant and crown. M1: 3.75 x 13 mm, M2: 3.75 x 8.5 mm, M3: 2.9 x 13 mm and M4: 2.9 x 8.5 mm. It was applied load was of 178 N at 0, 30 and 60 degrees in relation to implant long axis. Von Mises stress, maximum principal stress and microdeformation maps were evaluated. Result: M3 and M4 did show higher tension and higher microdeformation values than M1 and M2, especially when inclined forces were applied. However, M3 presented enhanced biomechanical behavior than M4. Conclusion: It can be concluded that reduce the diameter of the implants can disadvantage to the biomechanics during the application of forces, but the distribution and intensity of the stresses, as well as the micro deformation values can be improved if the length of the implant is increased

Stress distribution in lower second molar mesialization using mini-implants: a pilot study using 3D finite element analysis / Distribuição de tensões na mesialização do segundo molar inferior usando mini-implantes: um estudo piloto usando análise de elementos finitos 3D

Objective: to analyze the stress distribution in a 3D model that simulates second molar mesialization using two different types of mini-implants. Material and Methods: a mandible bone model was obtained by recomposing a computed tomography performed by a software program. The cortical and trabecular bone, a lower second molar, periodontal ligament, orthodontic tube, resin cement and the mini-implants were designed and modeled using the Rhinoceros 4.0 software program. The characteristics of self-drilling orthodontic mini-implants were: one with 7 mm length, 1 mm transmucosal neck section and 1.6 mm diameter and another with 5 mm length and 1.5 mm diameter. A total of 235.161 and 224.505 elements were used for the mesh. These models were inserted into the bone block and then subjected to loads of 200 cN (centinewton). The results were calculated and analyzed by the Ansys 17.0 software program for qualitative verification through displacement and maximum principal stress maps. Results: it was possible to observe that the periodontal ligament presented low displacement and stress values. However, the physiological values presented are among those capable to provide orthodontic movement, with compression and tensile area visualization staggered between 0.1 and -0.1 MPa (megapascal). Conclusion: within the limitations of the study, the mini-implants tested showed similar results where the load on the tooth allowed dental displacement (molar mesialization), with a tendency to rotate it, theoretically allowing the second molar to take the location of the first molar. (AU)

Objetivo: analisar a distribuição de tensões em um modelo 3D que simula a mesialização do segundo molar usando dois tipos diferentes de mini-implantes. Material e Métodos: um modelo de osso mandibular foi obtido por recomposição de uma tomografia computadorizada realizada por um software. O osso cortical e trabecular, um segundo molar inferior, ligamento periodontal, tubo ortodôntico, cimento resinoso e os mini-implantes foram projetados e modelados no software Rhinoceros 4.0. As características dos mini-implantes ortodônticos auto perfurantes foram: um com 7 mm de comprimento, 1 mm de secção transmucosa e 1,6 mm de diâmetro e outro com 5 mm de comprimento e 1,5 mm de diâmetro. Para a malha, foram utilizados 235.161 e 224.505 elementos. Esses modelos foram inseridos no bloco ósseo e então submetidos a cargas de 200 cN (centinewton). Os resultados foram calculados e analisados pelo software Ansys 17.0 para verificação qualitativa por meio de mapas de deslocamento e tensões máximas principais. Resultados: foi possível observar que o ligamento periodontal apresentou baixos valores de deslocamento e tensões. Porém, os valores fisiológicos apresentados são capazes de proporcionar movimentação ortodôntica, com visualização da área de compressão e tração escalonada entre 0,1 e -0,1 MPa (megapascal). Conclusão: dentro das limitações do estudo, os mini-implantes testados apresentaram resultados semelhantes onde a carga sobre o dente permitiu o deslocamento dentário (mesialização do molar), com tendência a girá-lo, permitindo teoricamente que o segundo molar ocupe do lugar do primeiro molar (AU)

Survival and prosthetic complications of monolithic ceramic implant-supported single crowns and fixed partial dentures: A systematic review with meta-analysis.

STATEMENT OF PROBLEM: Monolithic ceramic implant-supported restorations have been used to rehabilitate partially edentulous patients. However, knowledge of the survival and prosthetic complications of single crowns (SCs) and fixed partial dentures (FPDs) is limited. PURPOSE: The purpose of this systematic review with meta-analysis was to evaluate the clinical performance of monolithic ceramic implant-supported SCs and FPDs in terms of survival and prosthetic complication rates. MATERIAL AND METHODS: The systematic review was registered on the prospective register of systematic reviews (PROSPERO) (CRD42017078568). Five electronic databases were independently searched by 2 authors for articles published until May 2022. In addition, a hand search was performed in the nonpeer-reviewed literature, specific journals, and reference lists of included articles. A single-arm meta-analysis was performed by using the R program. The risk of bias and quality were assessed using the Cochrane risk of bias tools and the Newcastle-Ottawa scale. RESULTS: Twenty-eight studies were included in the quantitative synthesis. A total of 1298 monolithic ceramic implant-supported restorations (1116 SCs and 182 FPDs) were evaluated in 1193 participants, with a median observation time of 24 months (range: 12 to 72 months). Meta-analysis indicated the proportion of failures and prosthetic complication rates of 2% (95% confidence interval [CI]: 1% to 4%) for SCs. No difference was observed for monolithic zirconia and lithium disilicate SCs. In the FPDs, only monolithic zirconia was considered, with 1 failure reported totaling the proportion of failures of 0% (0% to 1%) and complication rates of 4% (0% to 12%). The most complications reported for both types of restorations were screw loosening, debonding, and minor chipping and were considered repairable. The included studies showed a low risk of bias and good quality. CONCLUSIONS: The use of monolithic ceramic implant-supported SCs, independent of ceramic material, and monolithic zirconia implant-supported FPDs should be considered an effective and safe treatment option because of favorable short-term survival and low prosthetic complications. However, additional well-conducted studies with a longer-term follow-up and direct comparison between veneered restorations are recommended to reassess clinical performance.

Impact of tilted implants for implant-supported fixed partial dentures: A systematic review with meta-analysis.

STATEMENT OF PROBLEM: The use of tilted implants has been considered a suitable option for completely edentulous patients. However, consensus on their clinical performance is lacking, specifically for partial rehabilitation. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the marginal bone loss and implant survival rate of tilted implants compared with those of axial implants for implant-supported fixed partial dentures (ISFPDs). MATERIAL AND METHODS: A systematic search of the MEDLINE/PubMed, Web of Science, Embase, Cochrane, and ProQuest databases and reference lists for articles published until May 2022 was performed by 2 independent reviewers without language or publication date restrictions. A meta-analysis was performed using the RevMan version 5.4 program. Quality assessments were performed using the Newcastle-Ottawa scale. RESULTS: Nine studies were included, totaling 258 participants and 604 implants (269 tilted implants and 335 axial implants). No significant differences were found between the tilted and axial implants for the implant survival rate (P=.81; risk ratio: 1.14). However, higher marginal bone loss values were observed for tilted implants (P=.001; mean difference: 0.12 mm). No significant heterogeneity was observed in either analysis. CONCLUSIONS: No significant relationship was found between tilted and axial implants for ISFPD rehabilitation. However, tilted implants presented greater risks of marginal bone loss than axial implants.

Migraine associated with tinnitus and hearing loss in adults: a systematic review.

OBJECTIVE: To describe evidence of migraine-associated tinnitus and hearing loss. DESIGN: This study was registered in PROSPERO and followed the PRISMA guidelines. The inclusion criteria were observational studies with subjects aged ≥18 years, in which the association between migraine and tinnitus and/or hearing loss was evaluated. Reviews, case reports, commentaries, letters to the editor, and studies that included individuals with some diseases were excluded. STUDY SAMPLE: The search yielded 698 articles from electronic databases. Six studies were eligible for this review with 26,166 participants. RESULTS: Most studies have shown an association between migraine and tinnitus, and between migraine and hearing loss. Studies have concluded that migraine presented high odds ratio, and hazard ratio for tinnitus. Another study found a strong association between these conditions (p < 0.001), and two investigations detected the presence of migraine in 10.1 and 22.5% of tinnitus patients. Migraine presented high odds ratio and hazard ratio for hearing loss. Additionally, the studies included were of good quality, adhering to most of the requirements on the JBI Critical Appraisal Checklist. However, a limitation of this review is the small number of studies included. CONCLUSIONS: Associations between migraine, tinnitus, and hearing loss were observed in the included studies.

The thermoplastic techniques or single-cone technique on the quality of root canal filling with tricalcium silicate-based sealer: An integrative review.

Background: The filling of the root canal system (RCS) is an important step in endodontic treatment and aims to obtain a three-dimensional sealing of the root canal spaces to prevent bacterial contamination. For this, the selection of an appropriate sealer must be performed synchronously with the choice of the root canal filling technique. This study aims, through an integrative review, to evaluate the quality of root canal filling by comparing thermoplastic and single-cone (SC) techniques. Material and Methods: The Medline/PubMed, Scopus, Web of Science and Virtual Health Library (VHL) databases were used to find articles published until November 2021. The eligibility criteria comprised articles that evaluating the quality of root canal filling comparing thermoplastic techniques with the SC technique using tricalcium silicate-based sealer. Studies that evaluated primary teeth, endodontic retreatment or perforations, different outcomes, and studies that considered artificial teeth or different sealer and material for obturation of different techniques were excluded. For articles that were not available for access, an additional contact with authors were considered. A total of 1699 articles were found. After duplicate removal, the title and abstract of 828 articles were screened. Sixteen articles were considered for full-text analysis, but only ten articles met the eligibility criteria. Data extracted from the studies were discussed and tabulated to allow the comparison of desired factors. Results: Concerning the formation of gaps/voids, the thermoplastic techniques showed better results than the SC technique in 3 articles. On the other hand, 2 articles reported no statistical difference between the tested techniques. In addition, about the penetration of tricalcium silicate-based sealer in the dentinal tubules, of the 5 articles selected, in 4 there was no significant difference between the tested techniques and only one study showed better penetration of the sealer when using thermoplastic techniques. Conclusions: The thermoplastic technique was better in most selected studies regarding gaps and voids, but regarding the penetration of the sealer into the tubules, both techniques were effective. Key words:Root canal filling, thermoplastic techniques, tricalcium silicate.

Effectiveness and safety of rotary and reciprocating kinematics for retreatment of curved root canals: a systematic review of in vitro studies.

Objectives: This systematic review (register-osf.io/wg7ba) compared the efficacy and safety of rotary and reciprocating kinematics in the removal of filling material from curved root canals. Materials and Methods: Only in vitro studies evaluating both kinematics during retreatment were included. A systematic search (PubMed/MEDLINE, Scopus, and other databases, until January 2021), data extraction, and risk of bias analysis (Joanna Briggs Institute checklist) were performed. Efficacy in filling removal was the primary outcome. Results: The search resulted in 2,795 studies, of which 15 were included. Efficacy was measured in terms of the remaining filling material and the time required for this. Nine studies evaluated filling material removal, of which 7 found no significant differences between rotary and reciprocating kinematics. Regarding the time for filling removal, 5 studies showed no difference between both kinematics, 2 studies showed faster results with rotary systems, and other 2 showed the opposite. No significant differences were found in apical transportation, centering ability, instrument failure, dentin removed and extruded debris. A low risk of bias was observed. Conclusions: This review suggests that the choice of rotary or reciprocating kinematics does not influence the efficacy of filling removal from curved root canals. Further studies are needed to compare the kinematics safety in curved root canals.

Polymorphisms of the serotonin receptors genes in patients with bruxism: a systematic review.

This study aimed to investigate if SNP rs6313, SNP rs2770304, SNP rs4941573, and SNP rs1923884 of the 5-HT2A receptor gene and SNP rs6295 of the 5-HT1A receptor gene are associated with bruxism etiology. METHODOLOGY: This systematic review was registered in PROSPERO (CRD42018094561). A search was conducted for articles published in or before May 2021. To qualify for eligibility in this review, the studies had to be case-controls, cohort or cross-sectional. The inclusion criteria were the articles with a group of patients with bruxism and a control group in which the presence of these SNPs was evaluated. The exclusion criteria were the investigations of other polymorphisms, the studies that did not consider a control group for comparison, case reports, and reviews. The NOS and JBI were used to evaluate the methodological quality of studies. RESULTS: We conducted this study with databases, such as Web of Science, Scopus, Embase, PubMed/MEDLINE, and ProQuest. We considered four studies eligible. A total of 672 participants were included,187 with sleep bruxism, 105 with awake bruxism, 89 with sleep and awake bruxism, and 291 controls. One study found a strong association between the SNPs rs6313, rs2770304 and rs4941573 of the 5-HT2A receptor gene and sleep bruxism. In one study, we considered the C allele of the SNP rs2770304 a risk factor for sleep bruxism. We found no significant results of other SNPs in sleep bruxers compared to controls. We found no positive association concerning the SNPs and groups of awake bruxism and sleep and awake bruxism. CONCLUSION: The different results regarding the SNPs in sleep bruxers could be explained by the genetic distinction between Chilean, Mexican, Japanese, and Polish population. More clinical trials and prospective studies must be conducted with larger sample size and in different ethnicities to confirm the results of this review.

Biomechanical Evaluation of Different Implant-Abutment Connections, Retention Systems, and Restorative Materials in the Implant-Supported Single Crowns Using 3D Finite Element Analysis.

This is an in silico study aimed to evaluate the biomechanical influence of different implant-abutment interfaces (external hexagon and Morse taper implants), retention systems (cement and screw retained), and restorative crowns (metal-ceramic and monolithic) using 3-dimensional finite element analysis (3D-FEA). Eight 3D models were simulated for the maxillary first molar area using InVesalius, Rhinoceros, and SolidWorks and processed using Femap and NEi Nastran software. Axial and oblique forces of 200 and 100 N, respectively, were applied on the occlusal surface of the prostheses. Microstrain and von Mises stress maps were used to evaluate the deformation (cortical bone tissue) and stress (implants/fixation screws/crowns), respectively, for each model. For both loadings, Morse taper implants had lower microstrain values than the external hexagon implants. The retention system did not affect microstrain on the cortical bone tissue under both loadings. However, the cemented prosthesis displayed higher stress with the fixation screw than the external hexagon implants. No difference was observed between the metal-ceramic and zirconia monolithic crowns in terms of microstrain and stress distribution on the cortical bone, implants, or components. Morse taper implants can be considered as a good alternative for dental implant rehabilitation because they demonstrated better biomechanical behavior for the bone and fixation screw as compared to external hexagon implants. Cement-retained prosthesis increased the stress on the fixation screw of the external hexagon implants, thereby increasing the risk of screw loosening/fracture in the posterior maxillary area. The use of metal-ceramic or monolithic crowns did not affect the biomechanical behavior of the evaluated structures.

Melatonin as an adjunctive treatment on dental procedures: A systematic review.

The systematic review tried to answer the following question: Does the melatonin administered systemically or topically ameliorate patients involved with oral health conditions or dental procedures? The systematic review has been registered in the PROSPERO (2021CRD42021095959). Eligibility criteria included only randomized controlled clinical trials (RCTs) with at least 10 participants that compared patients that received melatonin as a treatment before and/or after their oral intervention topically or systemically, with control patients. A search was performed in PubMed/MEDLINE, Web of Science, Cochrane Library, and Academic Google databases for articles up to February 2021. The Cochrane risk-of-bias tool for randomized clinical trials was used and revealed that the studies included presented low risk of bias for the majority of criteria assessed. It was selected 25 articles, of which only six did not demonstrate positive effects and three presented null effects with the use of melatonin. Melatonin has improved the inflammatory response in periodontal disease, dental surgeries, and mucositis of head and neck oncologic irradiated patients. In addition, it showed anxiolytic potential in patients that were submitted to dental procedures. In conclusion, melatonin favored the treatment of oral changes when used topically and systemically.