Effectiveness of ultrasonic activation over glycolic acid on microhardness, cohesive strength, flexural strength, and fracture resistance of the root dentin.

OBJECTIVES: The aim of this study was to evaluate the effectiveness of ultrasonic activation (US) over glycolic acid on microhardness, cohesive strength, flexural strength, and fracture resistance of root dentin, comparing with conventional final irrigation protocols. METHODS: Samples were obtained from 140 extracted bovine teeth and distributed into four test groups: microhardness (50 teeth), cohesive strength (15 teeth), flexural strength (15 teeth), and fracture resistance (60 teeth). In all four tests, specimens were subdivided into five groups, according to final irrigation protocols: G1: distilled water (DW); G2: 17% ethylenediaminetetraacetic acid (EDTA); G3: 17% glycolic acid (GA); G4: 17% EDTA + US; and G5: 17% GA + US. The duration time of each protocol was set in 1 min. After irrigation protocols, the Vickers tester was used to evaluate microhardness and the universal testing machine was used to evaluate the cohesive strength, flexural strength, and fracture resistance of the root dentin. One-way ANOVA test and the Tukey HSD were used for multiple comparison tests in all evaluations (α = 5%). RESULTS: In general, groups 2 (EDTA), 4 (EDTA + US), and 5 (GA + US) promoted the highest reduction of microhardness, being statistically different from other groups (p < 0.05). Cohesive strength, flexural strength, and fracture resistance data revealed that no differences between groups were observed (p > 0.05). CONCLUSIONS: The association of GA and US results in microhardness reduction, with no influence on cohesive strength, flexural strength, and fracture resistance of the root dentin. CLINICAL RELEVANCE: The use of US over GA has no influence on some mechanical properties of root dentin.

Effectiveness of ultrasonic activation associated to glycolic acid on smear layer removal, dentin structure and bond strength to root dentin

This study evaluated the effects of ultrasonic activation (US) associated to glycolic acid (GA) on smear layer, dentin structure and bond strength (BS) of filling/restorative material to root dentin. The roots were used for antimicrobial activity, dentin structure and BS evaluation, being distributed into seven groups, according to irrigation protocols: G1:DW+US; G2:17% EDTA; G3:QMix; G4:17% GA; G5:17% EDTA+US; G6:QMix+US; G7:17% GA+US. Scanning electronic microscopy, transmission electronic microscopy and push-out were performed, with specific statistical analysis for each evaluation. The highest smear layer removal occured in Groups 6 and 7 (p<0.05), and the largest collagen dispersion in Group 7, being similar to Group 2 and 5 (p>0.05). The highest BS of filling and restorative material occurred in Groups 6 and 7, and Groups 5, 6 and 7, respectively, being similars between them (p>0.05). The use of GA+US promoted effective smear layer removal and dentin structure preservation, improving the BS of filling/restorative material to root dentin.

Influence of the apical limit of instrumentation and photodynamic therapy on the postoperative pain of lower molars with asymptomatic apical periodontitis.

INTRODUCTION: The aim of present study was to evaluate the influence of apical limit of instrumentation and PDT on the postoperative pain of lower molars with asymptomatic apical periodontitis. METHODS: Forty patients were included in the present study and were divided into 4 groups (n=10), according to apical limit of instrumentation and use of PDT: instrumentation at 0.0 measurement; instrumentation at 0.0 measurement+PDT; instrumentation 1mm beyond 0.0 measurement; instrumentation 1mm beyond 0.0 measurement+PDT. In the PDT, the root canals were filled with 0.01% methylene blue, remaining for 5 min. The low-intensity laser was used with 100 mW, 660-690 nm wavelength), using intra-canal fibre. Root canals were irradiated for 90 s, delivering total dose of 9 J and energy density of 320 J/cm2. After root canal preparation and PDT protocols, root canals were filled with gutta-percha and AH Plus endodontic sealer, being sealed with composite resin.The evaluation of postoperative pain was performed by visual analog scale after 24, 48, 72 hours and 7 days. Data were analysed by specific statistical tests, at level of 5%. RESULTS: No statistical significant difference was observed among experimental groups in all evaluation periods, as well as in the intragroup analysis over time, regarding postoperative pain and analgesic medication consumption (p>0.05). CONCLUSIONS: Apical limit of instrumentation and PDT have no influence on the postoperative pain of lower molars with asymptomatic apical periodontitis.

Avaliação do nível de sujidade de sistemas rotatório e reciprocante após instrumentação e procedimentos de limpeza pré-esterilização / Evaluation of the dirt level of rotary and reciprocating systems after instrumentation and pre-sterilization cleaning procedures

Objetivos: avaliar a sujidade de limas rotatórias e reciprocantes após instrumentação e procedimentos de limpeza pré-esterilização. Materiais e métodos: 24 limas rotatórias e as 24 limas reciprocantes foram divididas, aleatoriamente, em dois grandes grupos. No primeiro grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, em seis subgrupos (SG): SG1 (controle negativo 1/n=1) ­ 1 lima rotatória não submetida à instrumentação; SG2 (controle negativo 2/n=1) ­ 1 lima reciprocante não submetida à instrumentação; SG3 (controle positivo 1/n=1) ­ 1 lima rotatória submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG4 (controle positivo 2/n=1) ­ 1 lima reciprocante submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG5 (grupo teste/n=10) ­ 10 limas rotatórias submetidas à instrumentação e submetidas ao protocolo de lavagem manual; SG6 (grupo teste/ n=10) ­ 10 limas reciprocantes submetidas à instrumentação e submetidas ao protocolo de lavagem manual. No segundo grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, nos mesmos subgrupos, substituindo, nos subgrupos 5 e 6, a lavagem manual pela lavagem em cuba ultrassônica. A análise do nível de sujidade foi realizada por microscopia eletrônica de varredura (MEV), sendo os dados submetidos ao teste de Kruskal-Wallis, com nível de significância de 5%. Resultados: a menor média de sujidade entre os grupos experimentais foi encontrada no SG5 do G1, sem diferença significante em relação aos demais grupos testados (p>0,05). Conclusão: conclui-se que os protocolos de limpeza testados não foram completamente efetivos para a remoção de sujidade das limas endodônticas.(AU)

Objective: to evaluate the dirt of rotary and reciprocating files after instrumentation and pre- -sterilization cleaning procedures. Materials and Methods: 24 rotary files and the 24 reciprocating files were randomly divided into two groups. In the 1st group, 12 rotary files and 12 reciprocating files were randomly divided into six subgroups (SG): SG1 (negative control 1/n=1) ­ 1 rotary file not subjected to instrumentation; SG2 (negative control 2/n=1) ­ 1 reciprocating file not subjected to instrumentation; SG3 (positive control 1/n=1) ­ 1 rotary file submitted to instrumentation and not submitted to any cleaning protocol; SG4 (positive control 2/n=1) ­ 1 reciprocating file submitted to instrumentation and not submitted to any cleaning protocol; SG5 (test group/n=10) ­ 10 rotary files submitted to instrumentation and submitted to the manual cleaning protocol; SG6 (test group/n=10) ­ 10 reciprocating files submitted to instrumentation and submitted to the manual cleaning protocol. In the 2nd group, the 12 rotary files and the 12 reciprocating files were randomly divided into the same subgroups, substituting, in subgroups 5 and 6, manual with ultrasonic bath cleaning. The analysis of dirt levels was performed by scanning electron microscopy (SEM), being the data submitted to the Kruskal-Wallis test, with a significance level of 5%. Results: the lowest average of dirt between the experimental groups was found in SG5 of G1, with no significant difference when compared to the other groups (p>0.05). Conclusion: it could be concluded that the cleaning protocols were not completely effective in removing dirt from endodontic files.(AU)

Influence of a glycolic acid-based final irrigant for photosensitizer removal of photodynamic therapy on the microhardness and colour change of the dentin structure.

INTRODUCTION: This study aimed to evaluate the influence of glycolic acid-based final irrigant for photosensitizer removal of photodynamic therapy on the microhardness and colour change of the dentin structure. METHODS: Eighty extracted single-rooted human incisors were used. Sample preparation and root split resulted in 160 samples, 80 samples being used for microhardness and 80 samples for colour change evaluation. In the first, PDT protocol was performed and 80 samples were randomly divided into 4 groups (n = 20), according to the final irrigation protocol: distilled water (DW); 17 % ethylenediaminetetraacetic acid (EDTA); QMix; 17 % glycolic acid (GA). Microhardness was evaluated using the Vicker tester, before and after, PDT and final irrigation protocols, calculating the percentage of microhardness reduction. In the second evaluation, PDT and final irrigation protocols were performed in the same way. Colour change was evaluated using digital spectrophotometer before and after these protocols, calculating the ΔE colour change using the CIELAB system (L*a*b* values). Specific statistical analysis was performed for both evaluations (α = 5%). RESULTS: The highest percentage of microhardness reduction was observed in 17 % EDTA, QMix and 17 % GA groups, with no significant difference among them (p > 0.05). Furthermore, none of these protocols was effective in photosensitizer removal, and all final irrigation protocols were statically similar to control group (p > 0.05). CONCLUSIONS: GA promotes microhardness reduction and also contributes to the colourization of dentin structure during the photosensitizer removal process, followingPDT .

Impacto da cirurgia ortognática na qualidade de vida em pacientes com diferentes deformidades orofaciais: revisão de literatura / Impact of orthognathic surgery on quality of life in patients with different orofacial deformities: literature review

Objetivos: analisar, por meio de revisão de literatura, o impacto da cirurgia ortognática na qualidade de vida de pacientes com diferentes deformidades orofaciais e identificar a concepção e a percepção dos pacientes em relação às correções de deformidades faciais de um quadro prévio ao procedimento até o momento da avaliação. Metodologia: foi realizado um levantamento da literatura nas bases de dados PubMed e Medline, utilizando os seguintes termos de busca: "ortognática", "distúrbios temporomandibulares", "qualidade de vida" e "psicossocial". Os artigos foram escolhidos nas línguas portuguesa e inglesa, dentre aqueles publicados entre os anos de 1990 a 2019. Considerações finais: a correção das deformidades esqueléticas faciais e das irregularidades dentárias associadas pela cirurgia ortognática apresenta um impacto positivo na qualidade de vida dos pacientes pela melhora harmônica dos ossos esqueléticos faciais, resultando em uma estética facial favorável e em um aprimoramento das funções do sistema estomatognático.(AU)

Objectives: to analyze, through literature review, the impact of orthognathic surgery on the quality of life of patients with different orofacial deformities and to identify the patients' conception and perception about corrections of facial deformities prior to the procedure until the moment of evaluation. Methods: a literature review was performed using the PubMed and Medline databases using the following search terms: "orthognathic", "temporomandibular disorders", "quality of life" and "psychosocial". The articles were chosen in Portuguese and English between 1990 and 2019. Final considerations: correction of facial skeletal deformities and associated dental irregularities, by orthognathic surgery, have a positive impact on patients' quality of life through the harmonious improvement of skeletal facial bones, resulting in a favorable facial esthetics and an improvement of the functions of the stomatognathic system.(AU)

Association of calcium hypochlorite, reciprocating instrumentation and photodynamic therapy: Antimicrobial analysis and effects on root dentin structure.

INTRODUCTION: This study aimed to evaluate the antimicrobial action of calcium hypochlorite(Ca[OCl]2) and sodium hypochlorite (NaOCl) with reciprocating instrumentation and photodynamic therapy(PDT), and its influence on root dentin structure. METHODS: One hundred and ten human teeth were used to antimicrobial evaluation, inoculated with Enterococcus faecalis and divided into 11 groups (n = 10): G1 - distilled water(control); G2-1 % NaOCl; G3-5.25 % NaOCl; G4-1 % Ca(OCl)2; G5-5.25 % Ca(OCl)2; G6-PDT; G7-distilled water + PDT; G8-1 % NaOCl + PDT; G9-5.25 % NaOCl + PDT; G10-1 % Ca(OCl)2+PDT; G11-5.25 % Ca(OCl)2+PDT. In all groups, except G6, the root canals were instrumented with #R50 Reciproc file in the working length in association with tested chemical auxiliary substance. The counting of colony forming units (CFUs) was performed to calculate the bacterial percentage reduction of each group. Following, 55 bovine teeth were used to microhardness evaluation and divided into the same 11 groups (n = 5), with no instrumentation and immersion in the tested protocols. The modification of root dentin microhardness was evaluated by using the Vicker tester. Finally, 33 bovine teeth were used to organic components evaluation and divided into the same 11 groups (n = 3), with no instrumentation and immersion in the tested protocols. The modification of organic components of root dentin was evaluated by light microscopy. Specific statistical analysis was performed for each evaluation. RESULTS: The higher bacterial reduction was observed in groups 3,4,5,8,9,10 and 11, with no statistical difference between them (p > 0.05). The higher microhardness reduction was observed in groups 8,9,10 e 11, with no statistical difference between them (p > 0.05). The highest modification on organic components was observed in groups 3,5,9 and 11, with no statistical difference between them (p > 0.05). CONCLUSIONS: The association of Ca(OCl)2, reciprocating instrumentation and PDT promotes effective antimicrobial action. Moreover, lower modification was induced in microhardness and organic components of root dentin, by using Ca(OCl)2 in low concentration associated to PDT.

Influence of final irrigation protocols and type of resin cement on bond strength of glass fiber posts in root dentin previously treated with photodynamic therapy.

INTRODUCTION: This study aimed to evaluate the influence of final irrigation protocols and type of resin cement on the bond strength of glass fiber posts (GFPs) in root dentin previously treated with photodynamic therapy (PDT). METHODS: One hundred root canals were prepared up to #4 Gates Glidden drill to receive the GFPs. All samples were subjected to PDT, and randomly divided into five groups (n = 20) according to final irrigation protocol: distilled water + ultrasonic activation [US]; 17% EDTA; QMix; 17% EDTA + US; and QMix + US. Each group was randomly divided into 2 subgroups (n = 10) according to the type of resin cement used for cementation of GFPs: Rely-X ARC dual-resin; or Rely-X U200 (#M, St Paul, MN, USA) self-adhesive resin cement. Bond strength was evaluated using the push-out test. Failure patterns were observed under an optical microscope. Bond strengths were compared using two-way ANOVA, followed by the Tukey post-hoc test; failure modes were compared using the chi-squared test (α = 5%). RESULTS: The use of US over final irrigants improved the bond strength of GFPs, regardless of resin cement used (p < 0.05). The type of resin cement did not influence the bond strength of GFPs (p < 0.05). There was a higher predominance of cohesive failure in all groups, regardless of resin cement tested (p < 0.05). CONCLUSIONS: The use of US on final irrigation improved the bond strength of GFPs, while the type of resin cement (dual or self-adhesive) did not influence the bond strength of GFPs in root dentin previously treated with PDT.

Influence of final irrigation protocols and endodontic sealer on bond strength of root filling material with root dentin previously treated with photodynamic therapy.

INTRODUCTION: The aim of this study was to evaluate the influence of final irrigation protocols and endodontic sealer on bond strength of root filling material on root dentin previously treated with photodynamic therapy (PDT). METHODS: One hundred root canals were prepared up to #F3 file of Pro-Taper system to receive the root filling material. All samples were submitted to PDT and randomly divided into five groups (n = 20) according to final irrigation protocols: Group 1-distilled water + ultrasonic activation (US); Group 2-17% EDTA; Group 3-QMix; Group 4-17% EDTA + US; Group 5-QMix + US. Each group was randomly divided into two subgroups (n = 10), according to the endodontic sealer used for cementation of gutta-percha points: AH Plus or MTA Fillapex. The bond strength was evaluated by a push-out test. The patterns of failure were observed under optical microscopy. The bond strength was evaluated using a two-way Anova followed by the Tukey post-hoc test, and the failure mode was evaluated using the chi-square test (α = 5%). RESULTS: The use of 17% EDTA and QMix associated or not to US improved the bond strength of root filling material with either endodontic sealer (p < 0.05). AH Plus showed higher bond strength than MTA Fillapex (p < 0.05). There was a higher predominance of cohesive failure in all groups, regardless of the tested final irrigation protocols and endodontic sealer (p < 0.05). CONCLUSIONS: The use of 17% EDTA and QMix, regardless of association with US, and the use of AH Plus improve the bond strength of the root filling material on root dentin previously treated with PDT.