Temporomandibular disorder in construction workers associated with ANKK1 and DRD2 genes

Abstract The study aimed to explore the influence of genetic polymorphisms in ANKK1 and DRD2 on the signs and symptoms of temporomandibular disorder (TMD) in construction workers. This cross-sectional study included only male subjects. All construction workers were healthy and over 18 years age. Illiterate workers and functionally illiterate workers were excluded. The diagnosis of TMD was established according to the Research Diagnostic Criteria for TMD (RDC/TMD). Genomic DNA was used to evaluate the genetic polymorphisms ANKK1 (rs1800497) and DRD2 (rs6275; rs6276) using Real-Time PCR. Chi-square or Fisher exact tests were used to evaluate genotypes and allele distribution among the studied phenotypes. The established alpha of this study was 5%. The sample included a total of 115 patients. The age of the patients ranged from 19 to 70 years (mean age 38.2; standard deviation 11.7). Chronic pain (87.7%), disc displacement (38.2%), and joint inflammation (26.9%) were the most frequently observed signs and symptoms. The genetic polymorphism rs6276 in DRD2 was associated with chronic pain (p=0.033). In conclusion, our study suggests that genetic polymorphisms in DRD2 and ANKK1 may influence TMD signs and symptoms in a group of male construction workers.

Resumo O objetivo do estudo foi explorar a influência de polimorfismos genéticos em ANKK1 e DRD2 sobre os sinais e sintomas da disfunção temporomandibular (DTM) em trabalhadores da construção civil. Este estudo transversal incluiu apenas indivíduos do sexo masculino. Todos os trabalhadores da construção civil eram saudáveis ​​e maiores de 18 anos. Foram excluídos os trabalhadores analfabetos e analfabetos funcionais. O diagnóstico de DTM foi estabelecido de acordo com o Research Diagnostic Criteria para DTM (RDC/TMD). O DNA genômico foi usado para avaliar os polimorfismos genéticos ANKK1 (rs1800497) e DRD2 (rs6275; rs6276) usando PCR em tempo real. Testes qui-quadrado ou exato de Fisher foram utilizados para avaliar genótipos e distribuição de alelos entre os fenótipos estudados. O alfa estabelecido deste estudo foi de 5%. A amostra incluiu um total de 115 pacientes. A idade dos pacientes variou de 19 a 70 anos (média de idade 38,2; desvio padrão 11,7). Dor crônica (87,7%), deslocamento de disco (38,2%) e inflamação articular (26,9%) foram os sinais e sintomas mais observados. O polimorfismo genético rs6276 em DRD2 foi associado a dor crônica (p=0,033). Em conclusão, nosso estudo sugere que polimorfismos genéticos em DRD2 e ANKK1 podem influenciar sinais e sintomas de DTM em um grupo de trabalhadores da construção civil do sexo masculino.

Influence of Root Canal Filling Techniques on Sealer Penetration and Bond Strength to Dentin

Abstract The influence of root canal filling techniques on the penetration of AH Plus into dentinal tubules was evaluated using confocal laser scanning microscopy (CLSM) and the impact on the bond strength of the filling material on the root dentin was evaluated using the push-out test. Roots of the maxillary central incisors (n=40) were prepared with ProTaper Universal and assigned to four groups: lateral condensation, vertical compaction, modified Tagger hybrid and single cone. After root canal filling with gutta-percha and AH Plus, along with the addition of 0.01% fluorescein, the roots were cut into 2-mm slices. CLSM was performed on the first slice of each root third, followed by the push-out test. The second slice was analyzed under SEM. ANOVA demonstrated a statistically significant difference between the root canal filling techniques and the root thirds (p<0.05). For percent penetration, Tukey's test showed that the vertical compaction (91.77±13.51), lateral condensation (89.18±10.91) and modified Tagger hybrid (87.53±15.42) presented the highest values, which significantly differed (p<0.05) from those of the single cone (78.19±22.46). For bond strength (MPa), lateral condensation (3.42±0.54) and vertical compaction (3.47±0.53) had the highest values (p<0.05), while the modified Tagger hybrid (2.19±0.41) and single cone (0.54±0.21) had the lowest. In conclusion, the lateral condensation, vertical compaction and Modified Tagger's hybrid techniques resulted in greater penetration and bond strength to the intra-radicular dentin.

Resumo Avaliou-se a influência da técnica obturadora na penetração do cimento AH Plus nos túbulos dentinários, por meio de microscopia confocal de varredura a laser (MCVL), e o impacto na resistência de união do material obturador à dentina, por meio do teste de push out. Raízes de incisivos centrais superiores (n=40) foram preparadas com ProTaper Universal e distribuídas em 4 grupos: Condensação lateral, Compactação vertical, Híbrida de Tagger Modificada e Cone único. Após obturação com guta percha e AH Plus acrescido de fluoresceína 0,01%, as raízes foram seccionadas em slices de 2,0 mm. O primeiro slice de cada terço foi submetido à MCVL e, posteriormente, ao teste de push out. O segundo slice foi analisado em MEV. ANOVA demonstrou diferença estatisticamente significante para as técnicas obturadoras e terços radiculares (p<0,05). Para o percentual de penetração, Tukey evidenciou que compactação vertical (91,77±13,51), Condensação lateral (89,18±10,91) e Híbrida de Tagger Modificada (87,53±15,42) apresentaram os maiores valores, estatisticamente diferentes (p<0,05) da Cone único (78,19±22,46). Na resistência de união (MPa), Condensação lateral (3,42±0,54) e Compactação vertical (3,47±0,53) obtiveram os maiores valores, diferentes (p<0,05) da Híbrida de Tagger Modificada (2,19±0,41) e da Cone único (0,54±0,21), que teve os menores valores. Concluiu-se que as técnicas obturadoras Condensação lateral, Compactação vertical e Híbrida de Tagger Modificada propiciaram maior penetração e resistência de união à dentina intrarradicular.

Silanated Surface Treatment: Effects on the Bond Strength to Lithium Disilicate Glass-Ceramic

Abstract: The aim of this study was to evaluate the effect of silanization protocols on the bond strength of two resin cements to a lithium disilicate glass-ceramic. Thirty-two ceramic discs were assigned to 2 groups (n=16): G1 - dual-cured resin cement and G2 - light-cured resin cement. Four subgroups were evaluated according to the used silanization protocol. The glass-ceramic was etched with 10% hydrofluoric acid for 20 s and silane was applied for 1 min, as follows: CTL - according to the manufacturer's instructions; HA - dried with hot air; NWA - washed and dried with water and air at room temperature; HWA - washed and dried with hot water and hot air. Thereafter, adhesive was applied and light-cured for 20 s. Silicon molds were used to prepare resin cement cylinders (1x1 mm) on the ceramic surface. The specimens were stored in deionized water at 37 °C for 48 h and subjected to a micro-shear test. The data were submitted to statistical analysis (?#61537;=0.05). Group G1 showed higher bond strengths than G2, except for the CTL and NWA subgroups. Differences as function of the silanization protocol were only observed in G1: HWA (25.13±6.83)≥HA (22.95±7.78)≥CTL(17.44±7.24) ≥NWA(14.63±8.76). For G2 there was no difference among the subgroups. In conclusion, the silanization protocol affected the resin cement/ceramic bond strengths, depending on the material. Washing/drying with hot water and/or hot air increased only the bond strength of the dual-cured resin cement.

Resumo: O objetivo do estudo foi avaliar o efeito da técnica de silanização na resistência de união de cimentos resinosos a uma vitrocerâmica. Trinta e dois discos de vitrocerâmica foram distribuídos em 2 grupos (n=16) (G1: cimento dual e G2: cimento fotoativado) e subdivididos em 4 grupos de acordo com a técnica de silanização. A vitrocerâmica foi condicionada com ácido fluorídrico a 10% por 20 s e o silano aplicado por 1 min de acordo com os subgrupos: CTL: de acordo com as instruções do fabricante, HA: secagem do silano com ar quente, NWA: lavagem e secagem com água e ar a temperatura ambiente, HWA: lavagem e secagem com água e ar quente. Após, o sistema adesivo foi aplicado e polimerizado por 20 s, e cilindros (1 x 1 mm) foram confeccionados com os cimentos sobre a superfície da cerâmica. Os espécimes foram armazenados em água destilada por 48 h e submetidos ao ensaio de microcisalhamento. Os dados foram submetidos à análise estatística (?#61537;=0,05). O grupo G1 apresentou maiores valores de resistência do que G2, exceto no subgrupo CTL e NWA. Houve diferença na técnica de silanização apenas para G1: HWA (25,13±6,83)≥ HA (22,95±7,78)≥ CTL (17,44±7,24)≥ NWA (14,63±8,76). Para G2 não houve diferença entre os subgrupos. Conclui-se que a técnica de silanização interferiu na resistência de união cimento/cerâmica dependendo do material utilizado. A lavagem e secagem com água e ar aquecidos promoveu maior valor de resistência apenas para o cimento dual.

Performance of RaCe Instrumentation System in Curved Root Canals: A Comprehensive Analysis by Three Study Methods

In this study, curved maxillary molar root canals were instrumented with RaCe rotary system to evaluate: 1. the occurrence of canal transportation using a radiographic platform; 2. the action of the instruments on the dentin walls, centering ability and canal enlargement by analysis of digital images; and the percentage of regular dentin surfaces and debris within the canal by histological analysis. Ten mesiobuccal roots of extracted human maxillary molars were embedded in acrylic resin and sectioned at the middle and apical thirds. Root canal shaping was performed using the RaCe rotary system at 250 rpm and 1 Ncm torque. Each instrument set was used five times according to a crown-down technique in the following sequence: 40/0.10, 35/0.08, 25/0.06, 25/0.04, 25/0.02 (working length - WL), 30/0.02 (WL) and 35/0.02 (WL). Each instrument was inserted until resistance was felt and then pulled back, followed by brushing movements towards all canal walls. Each specimen was assessed by three study methods: radiographic platform, digitized image assessment and histological analysis. The radiographic platform showed lack of apical transportation. No statistically significant difference (Wilcoxon test, p>0.05) was found between the middle and apical thirds regarding instrument action on dentin walls, centering ability, area of root canal enlargement, percentage of regular dentin surfaces and debris within the root canal. It may be concluded that RaCe system is a suitable method for the preparation of curved root canals, regarding the maintenance of root canal original path, action on dentin walls, canal enlargement and removal of debris from the root canal lumen.

O objetivo do presente estudo foi verificar a presença de desvio apical por meio da plataforma radiográfica, avaliar a ação dos instrumentos, centralização do preparo e ampliação por meio de imagens digitais do canal e calcular a porcentagem de superfícies regulares e presença de debris por meio da análise histológica. Dez raízes mésiovestibulares de molares superiores extraídos foram incluídos em blocos de resina e seccionados no terço médio e apical. O preparo do canal foi feito empregando o sistema RaCe, a 250 rpm e torque de 1 Ncm. Cada sistema rotatório foi usado 5 vezes no sentido coroa-ápice na seguinte sequência: 40/0.10, 35/0.08, 25/0.06, 25/0.04, 25/0.02 (comprimento de trabalho - CT), 30/0/02 (CT) e 35/0/02 (CT). Cada amostra foi avaliada por 3 métodos de estudo: plataforma radiográfica, imagem digital e análise histológica. A plataforma radiográfica mostrou ausência de transporte apical. Em relação à ação dos instrumentos sobre as paredes dentinárias, centralização do preparo, ampliação, porcentagem de superfícies regulares e presença de debris, o teste estatístico de Wilcoxon não mostrou diferença significativa entre os terços apical e médio. O sistema RaCe se mostrou adequado para o preparo de canais radiculares curvos em relação à manutenção do trajeto original do canal, ação sobre as paredes dentinárias, ampliação e remoção de debris da luz do canal radicular.

Staining susceptibility of methacrylate and silorane-based materials: influence of resin type and storage time

Introduction: The color stability of composite resins is a fundamental factor in their clinical behavior. Objective: To evaluate the color stability of composite resins of different colors exposed to a cola-based soft drink after different storage periods. Additionally, three methacrylate-based materials and one silorane-based material were evaluated. Material and methods: Specimens of three methacrylate-based materials (Opallis EA3, DA3 and T-Neutral; Filtek Supreme XT A3E, A3D and CT; 4 Seasons A3 Enamel, A3 Dentin and High Value) and one silorane-based material (Filtek P90 A3) were prepared, light-cured for 40 s, and manually polished with Sof-Lex discs. Samples were stored for 1 h, 24 h or 7 days. The color was evaluated by CIE-Lab system before and after immersion for 10 min in a cola-based soft drink. Color variation (ΔE) was calculated from individual values of L*, a* and b*, being considered imperceptible when < 1, clinically acceptable when ≤ 3.3, and clinically inacceptable when higher than 3.3. Data were evaluated by two-way Anova and Dunnett's T3 tests (α = 0.05). Results: There were differences among the resins (p < 0.001), with an interaction effect being also observed (p < 0.001). Storage time was not significant (p = 0.246). P90 showed a ΔE smaller than one unit at all studied times. Supreme XT CT and 4 Seasons High Value showed higher ΔE, but not above the critical value of 3.3. The only material that showed ΔE higher than 3.3 was Opallis DA3 after 1 h of storage. Conclusion: The silorane-based composite resin showed smaller ΔE at the times studied.