Impact of low-level laser therapy on the quality of life of patients with xerostomia undergoing head and neck radiotherapy: a systematic review.

PURPOSE: To carry out a systematic review to assess whether low-level laser therapy can improve the quality of life of patients with xerostomia undergoing head and neck radiotherapy. METHODS: A systematic search was performed through Embase, Medline/PubMed, Cochrane, Scopus, Web of Science, nonpeer-reviewed clinicaltrials.gov and LILACS. The strategy included clinical studies were selected that prospectively followed or evaluated the quality of life by directly comparing the use of low-level laser therapy for xerostomia induced by head and neck radiotherapy with alternative therapies without the use of a laser. The risk of bias in the studies was assessed by RoB 2.0 and Robins I. RESULTS: After all application of the predetermined criteria, four studies were included, dated between the years 2014 and 2023. Three studies described as randomized clinical trials were included, one of which was a randomized pilot study and only one was a prospective clinical trial. A total of 126 patients were evaluated, all four studies used the infrared wavelength, with two studies using the combination with the red wavelength. It was observed that low-level laser therapy can change the sensation of dry mouth, improving patients' quality of life. In addition, changes related to increased stimulated and unstimulated salivary flow were also identified. CONCLUSION: The use of low-level laser therapy has promising results on xerostomia, consequently improving the quality of life of patients undergoing radiotherapy in the head and neck region.

Efficacy of photobiomodulation in the treatment of avulsed teeth: A systematic review of animal studies.

The objective of this systematic review was to evaluate the effectiveness of photobiomodulation therapy (PBM) in managing avulsed teeth. This systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (i.e., "PRISMA") statement 2020 and was registered in the International Prospective Register of Systematic Reviews (i.e., PROSPERO) with number CRD42022362198. The participants, intervention, comparison, outcomes, and study design (i.e., PICOS) for the present study considered the following question: "Does the use of laser PBM in the treatment of teeth with avulsion influence tissue repair performance?" A literature search was performed in PubMed/MEDLINE, Embase, Web of Science, Cochrane Library, and ProQuest databases until January 2023. The SYRCLE's RoB tool (Systematic Review Center for Laboratory Animal Experimentation) for animal studies were used for quality assessment. A total of 7 in vivo studies published between 2011 and 2018 were included in this systematic review for qualitative analysis. All studies used Wistar rats, totaling 368 specimens that simulated tooth avulsion trauma. The effect of photodynamic therapy in the treatment of avulsed teeth was positive in 5 studies (significant increase in tissue repair) and negative in 2 studies, in which both studies with negative results kept teeth in saline solution before reimplantation and showed the longest time and power of laser application. PBM appears to be effective for tissue repair in the treatment of avulsed teeth, depending on the means of conservation of the avulsed tooth and the laser application protocol.

Efficacy of acellular xenogeneic dermal matrix graft in the treatment of multiple gingival recessions: systematic review and meta-analysis.

OBJECTIVE: This study aimed to compare the efficacy of acellular xenogeneic dermal matrix graft (AXDM) compared to connective tissue graft (CTG) in treating multiple gingival recessions. MATERIALS AND METHODS: A systematic search of electronic databases was conducted to identify randomized clinical trials (RCTs) that compared AXDM and CTG. The selected studies were subjected to bias risk assessment, data extraction, and meta-analyses. Parameters such as gingival recession height, width, mean percentage of root coverage, and complete root coverage were analyzed. RESULTS: Seven RCTs involving 146 patients were included. The meta-analyses indicated that CTG was statistically superior to AXDM in reducing gingival recession height at the final follow-up (mean difference: -0.104 mm, 95% confidence interval [CI]: -0.180-0.028, p = 0.008) and width at the final follow-up (mean difference: -0.285 mm, 95% CI: -0.541-0.030, p = 0.029). CTG also demonstrated a significantly higher mean percentage of root coverage at the 6-month follow-up (difference in means: -2.761 mm, 95% CI: -4.932-0.590, p = 0.013) and a higher percentage of complete root coverage at the 6-month follow-up (odds Ratio [OR]: 0.598, 95% CI: 0.4-0.892, p = 0.012) compared to AXDM. However, there was no significant difference in the number of teeth with complete root coverage between CTG and AXDM (OR: 1.610, 95% CI: 0.983-2.636, p = 0.058) and aesthetic outcomes (mean difference: 0.148, 95% CI: -0.277-0.573, p = 0.494). CONCLUSIONS: CTG is more effective than AXDM in treating multiple gingival recessions. This is evidenced by significant reductions in gingival recession height and width, a higher mean percentage of root coverage, and a greater percentage of complete root coverage at the 6-month follow-up. CLINICAL RELEVANCE: In some clinical situations an alternative to CTG is required for the treatment of multiple gingival recessions. AXDM, despite presenting clinical outcomes that are not as satisfactory as CTG, can be used for this purpose.

Efficacy of denture cleansers on Candida albicans adhesion and their effects on the properties of conventional, milled CAD/CAM, and 3D-printed denture bases.

OBJECTIVES: Evaluate the efficacy of denture cleaners on the adhesion of Candida albicans and their effects on the surface, optical, and mechanical properties of resins for conventional, milled, and 3D-printed denture bases. MATERIALS AND METHODS: A total of 240 resin samples were made, 120 for testing Candida albicans adhesion, optical stabilities (ΔE00), roughness (Ra), hydrophilicity (°), surface free energy (Owens-Wendt) and 120 samples for testing Candida albicans adhesion, surface microhardness (Knoop), flexural strength and modulus of elasticity in a three-point test, in which they were divided into 3 groups of denture resin (n = 40) and subdivided into 5 cleaners of dentures (n = 8). Data were evaluated by two-way ANOVA and Tukey's test for multiple comparisons (α = 0.05). RESULTS: Denture cleaners with an alkaline solution and dilute acid composition were those that showed the greatest effectiveness in reducing Candida albicans (P < 0.001), however 1% NaOCl significantly affected the properties of the resins (P < 0.05). Denture 3D-printed showed that the surface microhardness was significantly lower for all cleansers (P < 0.05). CONCLUSIONS: Listerine demonstrated superior efficacy in reducing Candida albicans with minimal effect on denture properties, whereas 1% NaOCl had a significant negative impact on the properties. The mechanical properties were significantly lower in 3D-printed resin than in other resins for all denture cleansers. CLINICAL RELEVANCE: Denture base materials are being sold to adapt to the CAD/CAM system, increasing the number of users of dentures manufactured with this system. Despite this, there is little investigation into denture cleaners regarding the adhesion capacity of microorganisms and the optical, surface and mechanical properties of dentures, thus requiring further investigation.

Influence of ceramic crown design (translucent monolithic zirconia vs. bilayered) of implant-supported single crowns after mechanical cycling.

OBJECTIVES: This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant-supported single crowns with external connections under mechanical cycling. MATERIALS AND METHODS: Fifty specimens were divided into groups: (1) metal-ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB). Specimens underwent mechanical cycling (5 × 106 cycles; 150 N) evaluating fatigue resistance (number of failures) and those that failed were subsequently subjected to fractographic analyses (stereomicroscope and scanning electron microscope) to evaluate failure location and area, and maximum fracture load was also measured. RESULTS: The failure-related survival rate (100%) and maximum fracture resistance of the MZrB were significantly higher than those of MC and Zr (50%; p < 0.05). There were no significant differences in the failure rate and fracture resistance when a CoCr base abutment was used or not in the translucent monolithic Zr groups (p > 0.05;MZrB vs. MZr). Failure location, with MC crowns' fractures, noted at the screw area (p = 0.043), while all-ceramic crowns were mostly in the cuspid and to failure area, the Zr group had the largest mean (15.55 ± 9.17 mm2) among the groups, significant difference only when compared with MC (1.62 ± 0.81 mm2) (p = 0.025). CONCLUSIONS: Translucent monolithic zirconia crowns exhibited significantly higher fatigue and fracture resistance compared with conventional MC and bilayered crowns. CLINICAL SIGNIFICANCE: The appropriate choice of material and manufacturing technique is crucial for predicting the higher clinical performance of single crowns. Enhanced mechanical resistance in terms of fatigue and fracture resistance can be achieved by replacing MC and bilayered restorations with computer-aided design and computer-aided manufacturing monolithic zirconia.

Clinical performance and patient-related outcome measures of digitally fabricated complete dentures: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: The demand to streamline workflow while increasing patient comfort and satisfaction in the manufacturing of removable complete dentures (CDs) is growing, and computer-aided design and computer-aided manufacturing (CAD-CAM) technology has gained prominence. However, a systematic review and meta-analysis of the clinical performance and patient-related outcome measures (PROMs) of digitally fabricated complete dentures is lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to determine whether digitally fabricated CDs improve the clinical performance and PROMs compared with conventionally fabricated CDs. MATERIAL AND METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was registered at the International Prospective Register of Systematic Reviews (CRD42023433909). This review aimed to address the question "Do digitally fabricated CDs improve clinical performance and PROMs compared with conventional CDs?" Two independent authors conducted electronic searches up to September 2023. Denture base retention and patient satisfaction were analyzed through the continuous outcome evaluated by mean difference and standard deviation, with 95% confidence intervals. The risk of bias in each study was assessed using the Risk of Bias In Non-randomized Studies of Interventions and the Risk of Bias based on the Cochrane risk of bias tool for randomized trials. The certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation. RESULTS: A total of 1505 articles were found during the search, and 16 were included in this review. The main outcomes were grouped into clinical performance (retention, adaptation or fit, clinician's denture quality assessment, masticatory efficiency, and occlusal force) and PROMs (patient satisfaction, oral health related quality of life, final choice, and willingness-to-pay). In terms of denture base retention, between conventional CDs and printed CDs analyzes, conventional CDs exhibited better retention (P=.02), but no significant difference was found between the conventional CDs and milled CDs (P=.20). In terms of patient satisfaction, no statistically significant difference was found between the manufacturing methods of digitally fabricated CDs (printed CD, P=.55; milled CD, P=.08). CONCLUSIONS: Digitally fabricated CDs showed similar or better clinical performance than conventional CDs, and different types of digital manufacturing processes for complete dentures did not influence PROMs.

Are CAD-CAM milled glass fiber posts better than prefabricated or custom glass fiber posts for endodontically treated teeth? A systematic review with meta-analysis.

STATEMENT OF PROBLEM: Prefabricated and custom glass fiber posts have been successfully used to reconstruct endodontically treated teeth. However, the performance of computer-aided design and computer-aided manufacture (CAD-CAM) milled glass fiber posts is unclear. PURPOSE: The purpose of this systematic review with meta-analysis was to compare the fracture and bond strength and cement layer thickness of CAD-CAM milled glass fiber posts with prefabricated or custom glass fiber posts. MATERIAL AND METHODS: The protocol was registered in the Open Science Framework (http://osf.io/65jm7). Two reviewers searched the PubMed/MEDLINE, Web of Science, Embase, Scopus, and ProQuest databases for articles up to September 2023. In addition, the reference lists were hand searched. A meta-analysis was performed by using the RevMan 5.4 program. The risk of bias was assessed using the RoBDEMAT tool. RESULTS: After screening, a total of 18 studies were included. The CAD-CAM milled glass fiber posts showed higher fracture strength (P=.02; Standardized Mean Difference [SMD]: 0.57; 95% Confidence Interval [CI]: 0.07 to 1.07), bond strength (P=.010; SMD: 1.07; 95% CI: 0.26 to 1.89), and lower cement layer thickness (P=.009; SMD: -2.94; 95% CI: -5.15 to -0.73) when compared with prefabricated glass fiber posts. However, fracture strength (P=.53; SMD: 0.38; 95% CI: -0.79 to 1.54) and bond strength (P=.90; SMD: -0.05; 95% CI: -0.81 to 0.72) were statistically similar between CAD-CAM milled and custom glass fiber posts. Significant and substantial heterogeneity was observed in all meta-analyzes (P<.01; I>60%). The studies sufficiently reported most domains related to bias, except for randomization of samples, sample size rationale and reporting and operator blinding. CONCLUSIONS: CAD-CAM milled and custom glass fiber posts provide an effective and safe option for restoring endodontically treated teeth, especially for weakened teeth or enlarged root canals. However, further well-designed clinical research is recommended to strengthen these findings.

Evaluation of Masticatory Function, Satisfaction, and Quality of Life Among Users of Complete Dentures Relined with Resilient Materials: A Systematic Review.

PURPOSE: To evaluate whether complete dentures (CDs) relined with long-term resilient liners (LTRLs) favor better masticatory function, satisfaction, and quality of life among completely edentulous patients compared to conventional CDs. MATERIALS AND METHODS: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and was registered in PROSPERO (the International Prospective Register of Systematic Reviews; CRD42021258700). The population, intervention, comparison, and outcome (PICO) purpose was to determine whether CDs relined with LTRLs favor better masticatory function, satisfaction, and quality of life among completely edentulous patients when compared to CDs. Searches were performed in the PubMed/MEDLINE, Embase, Scopus, Lilacs, BBO, and OpenGrey databases. Manual searches were also performed to identify additional primary studies. RESULTS: Overall, 3,953 articles were found. After removing duplicates, reading the articles, and applying the inclusion and exclusion criteria, 15 articles were selected for qualitative analysis, totaling 422 patients with follow-up periods ranging from 1 week to 3 years. Among these, 8 studies assessed masticatory function using different methods, 2 assessed satisfaction, 1 assessed quality of life, and 4 assessed more than one outcome. Through qualitative analysis, LTRLs showed satisfactory results in most studies when compared to CDs in relation to masticatory function, satisfaction, and quality of life. CONCLUSIONS: LTRLs favor better masticatory function, satisfaction, and quality of life among completely edentulous patients compared to CDs.

Effects of Overnight Denture Cleaners on Surface and Optical Properties of Conventional, CAD/CAM Milled, and 3D Printed Dentures.

OBJECTIVE: Evaluate the roughness and color stability of different types of resins used to immerse denture bases in various denture cleansers overnight. METODOLOGY: A total of 150 resin samples were made, which were divided into 3 groups of denture resin (conventional thermally activated, milled and 3D printed) (n= 50) and subdivided into 5 denture cleaners (Distilled water, Corega Tabs, Efferdent, NaOCl 1.0%, Listerine Cool Hint) (n= 10). The roughness properties (Ra) and chromatic difference (ΔE00) were evaluated during 90 days and 180 days of overnight cleaning. Data were evaluated by two-way ANOVA and Tukey's test for multiple comparisons (P<.05). RESULTS: Listerine had significantly higher Ra and ΔE values (P<.001) compared to other solutions, being significant in conventional resin at 180 days (P<.001). CONCLUSIONS: The use of Listerine as an overnight cleaner presents greater damage to the optical and surface properties of denture base resins, mainly with conventional resin, with 1% NaOCl being a valid option in relation to cost-benefit.

Are exercises with or without occlusal splints more effective in the reduction of pain in patients with temporomandibular disorders of myogenic origin? A systematic review

Abstract Temporomandibular disorders (TMD) is a term used to describe a set of clinical conditions that may compromise the temporomandibular joint (TMJ) and masticatory muscles and/or associated structures, considered the most frequent cause of orofacial pain of non-dental origin. In recent years, many forms of physical therapy have been used in the treatment of TMD to reduce pain and improve the range of mandibular movement present in this impairment. Among these resources are kinesiotherapy (exercise), electrothermal and manual therapy, acupuncture, training posture, mobilizations, and biofeedback. Objectives To determine if exercises with or without occlusal splints are effective in reducing pain in patients with temporomandibular disorders (TMD) of myogenic origin. Methodology This systematic review was registered in the International Prospective Register of Systematic Reviews (CRD 42019134244). Controlled trials published in PubMed, Scopus, and Cochrane Library following PRISMA guidelines up to April 2022 were randomized and included. The population above 18 years, which evaluated the effectiveness of exercise with or without occlusal splints in reducing pain in patients with TMD of myogenic origin, diagnosed through the Research Diagnostic Criteria for Temporomandibular Disorders, was also included. There was no restriction on the period of publication. Cochrane risk of bias analysis was performed. Results Of the five included articles, all showed a reduction of pain, but without significant differences between the interventions performed. Additionally, studies that evaluated the quality of life and mandibular movements showed a reduction in pain, but no significant differences between therapies. Conclusion The analyzed studies showed no difference in the improvement of pain, quality of life, and mandibular movements between the groups that performed only exercises or the associated treatments.

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

Abstract 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.

Three-Dimensional Finite Element Analysis of Varying Diameter and Connection Type in Implants with High Crown-Implant Ratio

Abstract The aim of this study was to evaluate the effect of varying the diameter, connection type and loading on stress distribution in the cortical bone for implants with a high crown-implant ratio. Six 3D models were simulated with the InVesalius, Rhinoceros 3D 4.0 and SolidWorks 2011 software programs. Models were composed of bone from the posterior mandibular region; they included an implant of 8.5 mm length, diameter Ø 3.75 mm or Ø 5.00 mm and connection types such as external hexagon (EH), internal hexagon (IH) and Morse taper (MT). Models were processed using the Femap 11.2 and NeiNastran 11.0 programs and by using an axial force of 200 N and oblique force of 100 N. Results were recorded in terms of the maximum principal stress. Oblique loading showed high stress in the cortical bone compared to that shown by axial loading. The results showed that implants with a wide diameter showed more favorable stress distribution in the cortical bone region than regular diameter, regardless of the connection type. Morse taper implants showed better stress distribution compared to other connection types, especially in the oblique loading. Thus, oblique loading showed higher stress concentration in cortical bone tissue when compared with axial loading. Wide diameter implant was favorable for improved stress distribution in the cortical bone region, while Morse taper implants showed lower stress concentration than other connections.

Resumo O objetivo deste estudo foi avaliar o efeito da variação do diâmetro e dos tipos de conexão na distribuição do estresse no osso cortical para implantes com a proporção coroa-implante. Seis modelos 3D foram simulados com os programas InVesalius, Rhinoceros 3D 4.0 e SolidWorks 2011. Os modelos foram compostos de osso da região mandibular posterior. Foram incluídos implantes de 8,5 mm de comprimento, diâmetro Ø 3,75 mm ou Ø 5,00 mm, e tipos de conexão como hexágono externo (EH), hexágono interno (IH) e cone Morse (MT). Os modelos foram processados usando os programas Femap 11.2 e NeiNastran 11.0 e usando uma força axial de 200 N e força oblíqua de 100 N. Os resultados foram registrados em termos da tensão principal máxima. O carregamento oblíquo mostrou alta tensão no osso cortical em comparação com a carga axial. Os resultados mostraram que os implantes com maior diâmetro apresentaram distribuição de tensões mais favorável, independentemente do tipo de conexão, enquanto que os implantes cone Morse apresentaram melhores distribuição de tensões comparado aos outros tipos de conexão, especialmente no carregamento oblíquo. Assim, os implantes de maior diâmetro foram mais favoráveis para distribuição das tensões na região de tecido ósseo cortical, enquanto que os implantes cone Morse apresentam menores concentrações de tensões do que as outras conexões.

Short implants versus longer implants with maxillary sinus lift. A systematic review and meta-analysis

Abstract This study compared the survival rate of dental implants, amount of marginal bone loss, and rates of complications (biological and prosthetic) between short implants and long implants placed after maxillary sinus augmentation. This systematic review has been registered at PROSPERO under the number (CRD42017073929). Two reviewers searched the PubMed/MEDLINE, Embase, LILACS, and Cochrane Library databases. Eligibility criteria included randomized controlled trials, comparisons between short implants and long implants placed after maxillary sinus augmentation in the same study, and follow-up for >6 months. The Cochrane Collaboration's tool for assessing the risk of bias in randomized trials was used to assess the quality and risk of bias of the included studies. The search identified 1366 references. After applying the inclusion criteria, 11 trials including 420 patients who received 911 dental implants were considered eligible. No significant difference was observed in the survival rate [p = 0.86; risk ratio (RR): 1.08; 95% confidence interval (CI): 0.46-2.52] or in the amount of marginal bone loss (p = 0.08; RR: −0.05; 95%CI: −0.10 to 0.01). However, higher rates of biological complications for long implants associated with maxillary sinus augmentation were observed (p < 0.00001; RR: 0.21; 95%CI: 0.10-0.41), whereas a higher prosthetic complication rate for short implants was noted (p = 0.010; RR: 3.15; 95%CI: 1.32-7.51). Short implant placement is an effective alternative because of fewer biological complications and similar survival and marginal bone loss than long implant placement with maxillary sinus augmentation. However, the risk of mechanical complications associated with the prostheses fitted on short implants should be considered.

Complications with PMMA compared with other materials used in cranioplasty: a systematic review and meta-analysis

Abstract Polymethyl methacrylate (PMMA) has been considered a suitable material for cranioplasty. However, no consensus has been reached concerning the best material for cranioplasty with regard to minimizing complications. Thus, this systematic review and meta-analysis aimed to compare the complication rates of PMMA with those of autologous bone and titanium mesh. This review was registered with PROSPERO (CRD42016042725). Systematic searches were conducted on PubMed/MEDLINE, Scopus, and Web of Science. The focus question was, "Do PMMA prostheses used in cranioplasty have complications rates similar to those of autologous bone and titanium mesh?" A meta-analysis of complication rates was performed on the basis of dichotomous outcomes assessed by risk ratio (RR) with corresponding 95% confidence intervals (CI). From 1014 data sources, 11 articles were selected according to eligibility criteria. These articles involved 1,256 individuals and 1,278 cranioplasties using autologous bone (n = 408), PMMA (n = 379), or titanium (n = 151). The follow-up period ranged from 63 days to 54.3 months. No difference was observed between the complication rates of PMMA and autologous bone (p = 0.94; RR, 0.98; 95%CI, 0.54-1.75) or between PMMA and titanium (p = 0.38; RR, 1.59; 95%CI, 0.57-4.48). Sub-analysis of the reasons for craniotomy (trauma/non-trauma) was conducted, which revealed no significant difference (p = 0.91; RR, 0.95; 95%CI, 0.37-2.42). The meta-analysis indicated that the use of PMMA yields complication rates that are near those of autologous bone and titanium mesh.

Análise das tensões em diferentes conexões de implante/ abutment / Stress analysis in different implant/abutment connections

O objetivo deste estudo foi comparar, por meio de uma análise fotoelástica, as tensões geradas na região peri-implantar dos implantes com diferentes conexões protéticas. Foram confeccionados 4 modelos em resina fotoelástica com implante unitário e coroa em alturas padronizadas. Mod 1: Hexágono Externo; Mod 2: Hexágono Interno; Mod 3: Cone-Morse e Mod 4: Corpo-único. Foi aplicada uma carga de 100N, tanto axial quanto obliquamente (45°) por meio da máquina de ensaio universal. O carregamento foi realizado em pontos fixos padronizados na superfície oclusal. Os resultados foram registrados fotograficamente por meio de uma câmera digital e analisados de forma qualitativa com auxílio do Adobe Photoshop. Tanto no carregamento axial quanto no carregamento oblíquo, observou-se que o implante de corpo-único apresentou a maior quantidade de franjas, ao contrário dos implantes de conexão interna. A diferença encontrada entre os modelos, quando da variação do sentido da carga, ocorreu devido ao fato de na carga oblíqua haver um maior número de franjas, e essas se concentram não só na região apical mas também do lado oposto à aplicação da carga, na região cervical. Concluiu-se que os implantes de conexão interna apresentaram a situação biomecânica mais favorável e os implantes de corpo-único apresentaram a maior concentração de tensões... (AU)

The aim of this study was to compare, by means of aphotoelastic analysis, the stresses generatedin the periimplantar regionof different implant/abutment connections. 4 modelswere fabricatedinphotoelastic resinwithsingle dental implantandstandardheight crowns. Mod 1: External Hexagon; Mod 2: Internal Hexagon; Mod 3: Morse-Taper and Mod4: One-Piece. It were applieda 100N axial and oblique (45°) loading by means of a universal testing machine. The loadwas appliedat standardized points on the occlusal surface. The results were recordedphotographicallyusinga digital camera andanalyzed qualitativelywiththeaid of the AdobePhotoshop software. Both inaxial and in the oblique loading, it was observed that one-piece implantshowed the highest number of fringes, apart from the internal connection implants. The differencebetween the models,whenthedirection of the load was changed, occurred duetotheoblique loading that caused greaternumber of fringes concentrated not onlyin the apical region, but also in the opposite side of the load application in the cervical region. It was concluded thattheinternal connection implants presented themost favorablebiomechanical situationand the one-piece implant presented the higheststress concentration... (AU)

Influence of diameter and intraradicular post in the stress distribution. Finite element analysis / Influência do diâmetro e do retentor intrarradicular na distribuição de tensões. Análise pelo método dos elementos finitos

Introduction: The biomechanical behavior of endodontically treated teeth depending on the selected restorative material and tooth situation to be restored. Objective: To analyze by the two-dimensional finite element method the biomechanical behavior of different diameters in intraradicular posts and teeth with coronal remaining of 2mm. Material and method: Six models were made with three types of posts, as follows: Glass fiber post, carbon fiber post, and cast metal post, both with diameter # 1 (1.1 mm in diameter) and # 2 (1.3 mm of diameter). The modeling was performed using the Rhinoceros 4.0 program. The FEMAP 10.2 and NEiNastran 9.2 programs were used to develop finite element models. The loading used was 100N for axial and oblique forces. The results were visualized using the von Mises stress map. The statistical analysis was made using analysis of variance (ANOVA) and Tukey post-test, with a significance level of 5%. Result: The oblique loading stress values were higher than the axial loading (p< 0.001) for both situations. The glass fiber post showed the lowest concentrations of stress on both loads (p< 0.001). The carbon fiber post presented significant difference compared to the cast metal post, only in the oblique load (p=0.007). The diameter did not increase the stress of the evaluated posts (p=0.302). Conclusion: The fiber posts were more favorable for restoration of endodontically treated teeth; the increase of diameter did not influence the increase of tension; the oblique load was more harmful for both posts and tooth structure.

Introdução: O comportamento biomecânico de dentes tratados endodonticamente é variável conforme o material restaurador selecionado e situação do dente a ser restaurado. Objetivo: Analisar por meio do método dos elementos finitos bidimensional o comportamento biomecânico de diferentes retentores intrarradiculares e diâmetros em dentes com 2mm de remanescente coronário. Material e método: Foram confeccionados seis modelos com três tipo de retentores: pino de fibra de vidro, pino de fibra de carbono e núcleo metálico fundido, ambos com diâmetro #1 (1,1mm de diâmetro) e #2 (1,3mm de diâmetro). A modelagem foi realizada através do programa Rhinoceros 4.0, e em seguida nos programas FEMAP 10.2 e NeiNastran 9.2 para desenvolvimento d os modelos de elementos finitos. Nos carregamentos foram utilizadas forças de 100N axial e oblíquo. Os resultados foram visualizados pelo mapa de tensão von Mises, e pela análise de variância (ANOVA) e pós-teste Tukey, com nível de significância à 5%. Resultado: O carregamento oblíquo apresentou maiores valores de tensões (p< 0,001). O pino de fibra de vidro apresentou menores concentrações de tensões em ambos os carregamentos (p< 0,001). O pino de fibra de carbono apresentou diferença significativa em relação ao núcleo metálico somente no carregamento oblíquo (p=0,007). O diâmetro não influenciou para o aumento de tensões dos retentores avaliados (p=0,302). Conclusão: Os pinos de fibras são mais favoráveis para restaurações de dentes tratados endodonticamente; O aumento do diâmetro não influenciou no aumento de tensões; A carga oblíqua é mais prejudicial à tanto para o retentor quanto para a estrutura dentária.

Systemic Trans- and Postoperative Evaluations of Patients Undergoing Dental Implant Surgery

OBJECTIVE: The aims of this study were to examine the trans- and postoperative systemic characteristics of patients undergoing dental implant surgery and to investigate the relationship between pre- and post- surgery anxiety levels. MATERIAL AND METHODS: Thirty-nine patients were analyzed in 3 call centers to determine anxiety levels, pain levels, and preoperative and postoperative histories using the State-Trait (STAI) questionnaire. RESULTS: A total of 93 dental implants were installed, with a success rate of 100%. The most frequently reported systemic disease was hypertension. There was a significantly higher rate of effective clamping (torque) to the mandibular bone than to the maxillary bone. The association between postoperative surgical complications and longer operative time was not significant, but there was a significant correlation between the alteration of mouth opening and daily routine activities and a significant decrease in anxiety levels between the day of surgery and the postoperative time point (p =0.006). CONCLUSION: A longer surgical time was associated with surgery-related complications and with a higher anxiety index on the preoperative evaluation.

Resina infiltrativa para tratamento de lesão de mancha branca: revisão de literatura / Resin infiltration for treatment of white spot lesion in adolescents: review

Resina infiltrativa é um material de baixa viscosidade para determinados tratamentos não invasivos, assim o objetivo desse estudo foi realizar uma revisão sistemática da literatura científica de pesquisas clínicas que abordaram o uso deste material restaurador dentário. A busca eletrônica foi realizada por 2 autores independentes utilizando o Pubmed, Scopus e BIREME, abrangendo o período de julho de 2009 e agosto de 2014 e somente na língua inglesa. , com os seguintes descritores: “dental caries”, “white spot”, “resin infiltration”, “dental caries treatment”. Foram obtidos 461 resumos, os quais foram lidos por dois revisores individualmente. Obtiveram-se 161 pesquisas no PUBMED, 168 na Scopus e por fim 121 na BIREME. Porém, apenas 14 artigos foram considerados nesta revisão, de acordo com os critérios de inclusão estabelecidos de acordo com PICOS. Consideraram-se os seguintes aspectos: pacientes com lesões de mancha branca em dentição decídua e/ou permanente, aplicação da resina infiltrativa, aplicação de vernizes fluoretados, gel fluoretado, associação das técnicas, ou tratamentos isolados, entre os procedimentos anteriores em pacientes que apresentavam lesões de mancha branca nas faces proximais ou vestibulares dos elementos dentais, ou avaliação da eficácia isolada da resina infiltrativa, taxa de sucesso, longevidade das técnicas utilizadas e o mascaramento da lesão de mancha branca (alteração de cor). A resina infiltrativa demonstrou ser bem sucedida, principalmente nos primeiros seis meses das avaliações clínicas e parece ser eficaz quanto ao poder de mascaramento das lesões de mancha branca, além de limitar o avanço das lesões de cárie

Infiltrative resin is a low viscosity material for certain non-invasive treatments, so the aim of this study was to perform a systematic review of scientific literature clinical research that addressed the use of this dental restorative material. For the literature search used the site Pubmed, Scopus and BIREME in the period from July 2009 to August 2014, with the following descriptors: “dental caries”, “white spot”, “resin infiltration,” “dental caries treatment”. That were obtained 461 abstracts, which were read by two reviewers individually. There was obtained 161 searches in PubMed, 168 in Scopus and finally 121 in BIREME. However, only 14 articles were considered in this review, according to the inclusion criteria established in accordance with PEAKS. The following aspects were considered: patients with white spot lesions in deciduous dentition and / or permanent application of resin infiltration, application of fluoride varnish, fluoride gel, association techniques, or single treatments, between the above procedures in patients with white spot lesions on the proximal surfaces or vestibular dental elements, or assessment of efficacy alone infiltrative resin, success rate, longevity of the techniques used and the masking of white spot lesions (color change). The infiltrative resin proved to be successful, especially in the first six months of clinical evaluations and appears to be effective as to the power of blinding white spot lesions and limiting the advance of caries lesions

Effect of the Parafunctional Occlusal Loading and Crown Height on Stress Distribution

The aim of this study was to assess, by the three-dimensional finite element method, the influence of crown-to-implant ratio and parafunctional occlusal loading on stress distribution in single external hexagon implant-supported prosthesis. Computer-aided design software was used to confection three models. Each model was composed of a block bone and an external hexagon implant (5x10.0 mm) with screw-retained implant prostheses, varying the height crown: 10, 12.5 and 15 mm. Finite element analysis software was used to generate the finite element mesh and to establish the loading and boundary conditions. Normal (200 N axial and 100 N oblique load) and parafunctional forces (1,000 N axial and 500 N oblique load) were applied. The results were visualized by von Mises and maximum principal stress. In comparison with the normal occlusal force, the parafunctional occlusal force induced an increase in stress concentration and magnitude on implant (platform and first threads) and screw (neck). The cortical bone showed the highest tensile stress under parafunctional force (oblique load). The stress concentration increased as the crown height increased. It was concluded that: increasing the C/I increased stress concentration in both implant components and cortical bone; parafunctional loading increased between 4-5 times the value of stresses in bone tissue compared with functional loading; the type of loading variation factor is more influential than the crown-to-implant factor.

O objetivo deste estudo foi avaliar, através do método dos elementos finitos tridimensionais, a influência do carregamento oclusal parafuncional e da altura da coroa na distribuição das tensões em próteses unitárias implantossuportadas de hexágono externo. Foram confeccionados três modelos com o auxílio de programas de desenho assistido. Cada modelo foi composto por um bloco ósseo da região molar mandibular, por um implante de tipo hexágono externo (5x10,0 mm) e por coroa com diferentes alturas: 10, 12,5 e 15 mm. Os modelos foram exportados para o programa de elementos finitos NEiNastran 9.0, para geração das malhas e estabelecer as condições de contorno. Aplicou-se uma carga funcional (200 N axial e 100 N oblíqua), bem como uma carga parafuncional (1.000 N axial e 500 N oblíqua). Os resultados foram visualizados por meio de mapas de Tensão de von Mises e mapas de Tensão Máxima Principal. O carregamento parafuncional induziu um aumento da área de distribuição e da magnitude das tensões no implante (plataforma e primeiras roscas) e parafuso (pescoço) em comparação com o carregamento funcional. A cortical óssea apresentou maiores áreas de tensão por tração sob carregamento parafuncional oblíquo. A concentração de tensões aumentou à medida que aumentou a altura da coroa. O aumento da altura da coroa induziu um aumento na concentração de tensões, tanto nos componentes do implante, quanto na cortical óssea; o carregamento parafuncional induziu um aumento entre 4-5 vezes da magnitude das tensões no tecido ósseo; o tipo de carregamento apresenta-se como um fator de variação mais influente do que a proporção coroa/implante.

A importância da geometria dos implantes para o planejamento em reabilitação oral: revisão de literatura / The importance of implants geometry for planning in oral rehabilitation: literature review

O desenho da estrutura do implante ainda é um questionamento por parte dos profissionais, visto que suas variações pode influenciar para a distribuição de tensões de maneira mais favorável ao longo do tecido ósseo. Assim, o objetivo deste estudo foi realizar uma revisão de literatura abordando o tema geometria dos implantes osseointegráveis estabelecendo respostas que procure fundamentar as reabilitações orais de acordo com as variações dos implantes que existem no mercado. Foi realizada uma busca detalhada no periódico PubMed/Medline e Bireme, com os descritores: “dental implants cylinder”; “dental implants thread”; “dental implants geometry”, até maio de 2014. A busca resultou em um total de 798 artigos, sendo realizado uma análise dos títulos e resumos, selecionando 18 artigos e realizado a complementação com um 1 livro da área, que avaliaram a influência das diferentes geometrias dos implantes, procurando comparar as diferentes formas de geometria e roscas para posterior discussão e conclusões. Dessa forma, conclui-se que os implantes rosqueáveis são mais utilizados, devido as suas vantagens em relação a dissipação de tensões e estabilidade primária. As variações dos diferentes tipos de roscas existentes apresentam influência para a dissipação das tensões

The design of implant structure is still a questioning to the professionals, while their variations can to influence of stress distribution favorably to bone. Therefore, the aim of study was to review addressing the topic of osseointegrated implants design establishing answers for the patient oral rehabilitation, according variations existing on the market. It was conducted a detailed search strategy by the PubMed/ Medline and Bireme, it was used as descriptors: “dental implants cylinder”; “dental implants thread”; “dental implants geometry”, until May 2014. From 798 articles, after review were selected 18 articles and 1 specific area book. The results were divided to compare design of implant and threads for further discussion and conclusions. Thus, conclude that the threads implants are best used because of its advantages with respect to the stress distribution and stability primary. The variations of the differents types of threads, have influence for stress distribution