A systematic review and meta-analysis on the effects of phototherapy on postoperative pain in conventional endodontic reintervention.

OBJECTIVES: This systematic review and meta-analysis (SRM) aimed to evaluate the efficacy of laser phototherapy (LPT) on the reduction in postoperative pain (PP) of endodontic origin after conventional/non-surgical reintervention of root canals. METHODS: This SRM was registered with PROSPERO (CRD42021243500) and followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Meta-analysis was conducted using R software with the "META" package, the mean difference (MD) measure of effect was calculated, and the fixed effect model was applied with a 95% confidence interval (CI). The Cochrane collaboration scale was used to assess the risk of bias and the GRADE tool to assess the quality of evidence. RESULTS: Initially, 1028 articles were found, and five articles were included. Most studies were classified as "low" risk of bias. Of the five clinical studies, four showed a significant decrease in PP after endodontic reintervention in the LPT groups compared to the control group, especially in the first four days after the intervention. In symptomatic teeth with multiple roots, LPT led to less PP at 24 h (MD -0.52 [-1.03; -0.02] p = .04). However, no significant difference between the groups was found at 48 and 72 h (p > .05). The certainty of the evidence was classified as low. CONCLUSION: Despite the limitations of this SRM, LPT was shown to be a promising alternative for reducing and controlling PP in conventional endodontic reintervention. CLINICAL SIGNIFICANCE: The use of LPT in endodontic reintervention may be a safe and promising alternative to clinically efficacious agent for use in the management of PP in this procedure.

In vitro study on how photodynamic therapy and calcium hydroxide medication influence adhesive interface properties of glass-fiber posts to intraradicular dentin.

PURPOSE: This in vitro study evaluated the influence of antimicrobial photodynamic therapy (aPDT), using methylene blue (MB) as photosensitizer (PS) and calcium hydroxide (CH) as intracanal medication on adhesive bond strength, sealing, and integrity of the luting interface of glass-fiber posts to different thirds of endodontically treated root canal dentin. MATERIAL AND METHODS: 102 incisors were sorted into 6 groups: a negative control irrigated with deionized water; a positive control irrigated with deionized water and filled with CH; CH + MB 50 mg/L without laser radiation; CH + MB 100 mg/L without laser radiation; CH + MB 50 mg/L radiated by red laser; and CH + MB 100 mg/L radiated by red laser. Push-out bond strength (n = 8), adhesive interface sealing (n = 3), and volume and quantification of voids (n = 6) were assessed using a universal testing machine, confocal laser scanning microscope, and computerized microtomography, respectively. Scanning electron micrographs were obtained from representative samples to qualify the fracture patterns. Push-out bond strength and adhesive interface integrity data were subjected to 2-way ANOVA for repeated measures followed by Tukey's test (α = 0.05). Adhesive interface sealing was evaluated by the inter-examiner Kappa test and submitted to Kruskal-Wallis and Dunns tests (α = 0.05). RESULTS: Assessing the apical region, the positive control and MB100WA + Ca(OH)2 groups showed lower adhesive bond strength compared to the MB100A + Ca(OH)2 group (P < 0.05). The cervical third showed higher bond strength than the apical third for the positive control, MB50WA + Ca(OH)2, MB100WA + Ca(OH)2, and MB50A + Ca(OH)2 groups (P < 0.05). A prevalence of mixed failure was observed in all experimental groups. There were no statistically significant differences in adhesive interface sealing for any of the parameters assessed (P > 0.05). MB100WA + Ca(OH)2 and MB100A + Ca(OH)2 groups promoted a higher volume and quantification of voids compared to the negative control group evaluating the cervical third (P < 0.05). In general, there were no differences in the quantification of voids comparing the intraradicular thirds (P > 0.05), differently to the volume of voids in which, in general, the cervical third promoted higher values compared to the middle and apical thirds (P < 0.05). CONCLUSION: aPDT with methylene blue PS at 50 mg/L associated with calcium hydroxide as intracanal medication demonstrated satisfactory bond strength, sealing, and integrity of the adhesive interface at any intraradicular depth.

Do different adhesives influence the color stability and fluorescence of composite restorations after aging?

Abstract This study aimed to evaluate the influence of dental adhesive color on the chromatic stability and fluorescence intensity of composite resin restorations of different thicknesses. Ninety bovine enamel samples were obtained and restored with resin composite varying thicknesses of restorative material and enamel (1.0 mm enamel and 1.0 mm composite; 1.5 mm enamel and 0.5 mm composite; 0.5 mm enamel and 1.5 mm composite). The restorations were made of composite resin (Opallis E-bleach H) using different types of dental adhesives: Ambar, Ambar APS, and Single Bond Universal (n=10). The samples were subjected to color measurement tests in a spectrophotometer using CIEDE2000 and fluorescence intensity measurements before and after aging in a red wine coloring solution. Data were subjected to analysis of variance (ANOVA) and Tukey's test (α = 0.05). There were no statistically significant changes in color stability or fluorescence intensity for restorations made of different materials or thicknesses (p>0.05). Single Bond Universal showed greater color stability at 0.5 mm thickness (ΔE00 = 4.4 ± 1.6) compared to other thicknesses of the same material (p=0.003), as well as a greater difference in fluorescence intensity after aging at 1.5 mm thickness (-414.9 ± 103.8) compared to other materials (p=0.0002). Overall, it was concluded that the different adhesive systems did not influence the color stability and fluorescence of restorations of different thicknesses.

Resumo O objetivo deste estudo foi avaliar a influência da cor do adesivo dental na estabilidade cromática e intensidade de fluorescência das restaurações de resina composta de diferentes espessuras. Foram obtidos noventa amostras de esmalte bovino que foram restaurados com resina composta, variando a espessura do material restaurador e do esmalte (1,0 mm de esmalte e 1,0 mm de compósito; 1,5 mm de esmalte e 0,5 mm de compósito; 0,5 mm de esmalte e 1,5 mm de compósito). As restaurações foram feitas de resina composta (Opallis E-bleach H) utilizando diferentes tipos de adesivos odontológicos: Ambar, Ambar APS, e Single Bond Universal (n=10). As amostras foram submetidas a testes de medição de cor em um espectrofotômetro usando CIEDE2000 e medições de intensidade de fluorescência antes e depois do envelhecimento em uma solução de coloração de vinho tinto. Os dados foram submetidos à análise de variância (ANOVA) e ao teste de Tukey (α = 0,05). Não houve mudanças estatisticamente significativas na estabilidade da cor ou intensidade de fluorescência para restaurações feitas de diferentes materiais ou espessuras (p>0,05). O Single Bond Universal mostrou maior estabilidade de cor a 0,5 mm de espessura (ΔE00 = 4,4 ± 1,6) em comparação com outras espessuras do mesmo material (p=0,03), bem como uma maior diferença na intensidade de fluorescência após o envelhecimento a 1,5 mm de espessura (-414,9 ± 103,8) em comparação com outros materiais (p=0,0002). Em geral, concluiu-se que os diferentes sistemas adesivos não influenciaram a estabilidade de cor e a intensidade de fluorescência das restaurações de diferentes espessuras.

Effects of methylene blue and curcumin photosensitizers on the color stability of endodontically treated intraradicular dentin.

BACKGROUND: Photodynamic therapy with photosensitizers can reduce the microbial load. However, few studies have evaluated the effects of photosensitizers on the color stability of endodontically treated intraradicular dentin. This in vitro study investigated the effects of methylene blue and curcumin photosensitizers used in photodynamic therapy on the color stability of intraradicular dentin. METHODS: Sixty human incisors were divided into three experimental groups according to the photosensitizer solutions used and their concentrations: methylene blue (25 mg/L), curcumin (1000 mg/L), and curcumin (1500 mg/L). The color stability of endodontically treated intraradicular dentin was evaluated using a portable reflectance spectrophotometer before and after the samples been storage in 2 mL of the photosensitizer solutions during 5 min (n = 20). Color stability data were subjected to a normality test, and statistical analysis was performed using the one-way analysis of variance and Tukey least significant difference test (α = 0.05). RESULTS: Samples treated with 25 mg/L methylene blue photosensitizer showed a higher level of color alteration than those stored in 1000 mg/L curcumin (p = .03322). However, there was no significant difference in the color alteration profiles between the samples treated with 25 mg/L methylene blue and 1500 mg/L curcumin (p = .36428). Furthermore, there was no difference in the color alteration profiles between the dentin samples immersed in 1000 mg/L and 1500 mg/L curcumin photosensitizer solutions (p = .45321). CONCLUSIONS: Methylene blue and curcumin photosensitizers influenced the color stability of endodontically treated intraradicular dentin, and this color alteration exceeded the clinical acceptability threshold. Samples treated with 25 mg/L methylene blue showed the highest level of color alteration.

Role of adhesive systems on the luting interfaces thickness of ceramic laminate veneers

Abstract This in vitro study aimed to evaluate the effects of different luting protocols on the thickness of luting interface of ceramic laminate veneers. Thirty-six lithium disilicate blocks (7 × 8 × 0.6 mm) were cemented onto bovine enamel. They were divided into 6 groups based on the luting protocol (no previous photoactivation of the dental adhesive; previous activation of the dental adhesive only on enamel surface; and previous photoactivation of the dental adhesive on both the enamel surface and inner surface of ceramic laminate) and the luting materials used (Single Bond Universal/RelyX Veneer and Tetric N Bond/Variolink Veneer). The luting interface thickness of ceramic laminate veneers was evaluated using a laser scanning confocal microscope (n = 6). The luting interface measurements were analyzed using 2-way ANOVA and the Tukey least significant difference test (α = 0.05). Prior activation of the adhesive on the dental enamel and inside the ceramic laminate exhibited higher luting interface thickness than that with no prior photoactivation of both luting materials (p < 0.05). Specimens cemented with Tetric N Bond/Variolink Veneer, submitted for prior photoactivation of the adhesive on the dental enamel and on both dental enamel and inner surface of ceramic, exhibited lower luting interface thickness than those luted with Single Bond Universal/RelyX Veneer (p < 0.05). The prior photoactivation of dental adhesives influenced the thickness of luting interface in laminate restorations. Tetric N Bond/Variolink Veneer yielded more satisfactory results than Single Bond Universal/RelyX Veneer when the adhesive was light activated.