Influence of antimicrobial photodynamic therapy on the bond strength of endodontic sealers to intraradicular dentin: A systematic review and meta-analysis.

BACKGROUND: The objective of this systematic review and meta-analysis (SRMA) was to investigate the influence of antimicrobial photodynamic therapy (aPDT) on the bond strength of endodontic sealers to intraradicular dentin. METHODS: This SRMA followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered in the International Prospective Registry of Systematic Reviews (PROSPERO) (CRD42022319856). A population, intervention, control, and outcome (PICO) question was formulated: "Does antimicrobial photodynamic therapy decrease the bond strength of root canal sealers?". A literature search was performed in PubMed/MEDLINE, Embase, Web of Science, Scopus, Cochrane Library, and ProQuest databases until July 2022. Joanna Briggs Institute Critical Assessment Guidelines for Quasi-Experimental Studies were used for quality assessment. The meta-analysis was based on the inverse variance (IV) method (p<0.05). RESULTS: Out of an initial 345 articles, 8 in vitro studies were included, published between 2013 and 2022. The studies were qualitatively analyzed; two studies showed a positive effect, two studies a negative effect, and the other studies showed no effect on bond strength of endodontic sealers to intraradicular dentin. Seven of the studies were included in the SRMA, which indicated that there was no significant difference in bond strength when using aPDT (P = 0.90; MD: -0.03; 95% CI: -0.46 to -0.41). There was a high level of evidence for each meta-analysis outcome. CONCLUSION: It can be concluded that the use of aPDT as a method of root canal disinfection does not negatively influence the bond strength of endodontic sealers in the root canal.

Influence of anti-allergic drugs used systemically on the process of root resorption during delayed tooth replantation: A study in rats.

BACKGROUND/AIM: Anti-allergic drugs can inhibit the hard tissue resorption process, and due to similarities between root resorption and bone mechanisms, it can be inferred that these drugs may also control root resorption. The aim of this study was to analyze the effects of anti-allergic drugs used systemically on the process of root resorption following delayed tooth replantation. MATERIALS AND METHODS: Thirty-two maxillary right incisors of rats were extracted and subsequently replanted. Rats were divided into four groups according to the anti-allergic drug administered: the rats in groups DEX, Q, and MO were treated systemically with dexamethasone phosphate, quercetin, and montelukast, respectively, and no systemic medication was administered to rats in group C. After 60 days, the animals were euthanized, and the specimens were processed for histomorphometric and immunohistochemical analyses. Statistical significance was set at P < .05. RESULTS: There were no significant differences between the groups in terms of inflammatory resorption, replacement resorption, or presence of tartrate-resistant acid phosphatase. In terms of events occurring in the periodontal ligament space, there was a difference between groups Q and MO due to the presence of dental ankylosis and inflammatory connective tissue (P < .05). A difference in inflammatory cells was also observed through CD45 immunolabeling between the DEX and Q groups when compared to the C group (P < .05). CONCLUSION: The systemic administration of anti-allergic drugs did not have an effect on the process of root resorption following delayed tooth replantation.

Influência da terapia fotodinâmica na resistência de união do cimento obturador à dentina intrarradicular e na morfologia da interface adesiva / Influence of photodynamic therapy on the bond strength of an MTA based root canal sealer to intraradicular dentin and morphology of the adhesive interface

Introdução: A terapia fotodinâmica (TFD) é utilizada como coadjuvante ao tratamento endodôntico para potencializar a redução microbiana no sistema de canais radiculares. No entanto, a literatura carece de estudos sobre as consequências da TFD na resistência de união do cimento obturador à dentina intrarradicular. O objetivo deste estudo foi avaliar a influência da TFD com azul de metileno na resistência de união do cimento obturador (MTA Fillapex) utilizando o teste de push-out, analisar o padrão de fratura das amostras representativas por microscopia eletrônica de varredura (MEV) e a morfologia da interface adesiva intrarradicular pela microscopia confocal de fluorescência (MCF). Material e Métodos: Cinquenta e cinco dentes bovinos foram utilizados para simular o tratamento endodôntico. O preparo biomecânico foi realizado em todos os canais radiculares e os espécimes foram distribuídos em 5 grupos: controle (água deionizada); azul de metileno 50 mg/L (AM50SL); azul de metileno 100 mg/L (AM100SL); azul de metileno 50 mg/L + laser vermelho 660nm (AM50L) (TFD); e de azul de metileno 100 mg/L + laser vermelho 660nm (AM100L) (TFD). A resistência de união do cimento obturador à dentina foi mensurada usando uma máquina de teste universal (n=8) e as amostra representativas analisadas em MEV. A morfologia da interface adesiva intrarradicular foi analisada pela MCF. Os dados de resistência de união foram submetidos ao teste de KruskalWallis para comparação entre grupos e ao teste de Friedman para comparação entre terços (α=.05). Resultados: Houve diferença estatística significante para o grupo azul de metileno 100 mg/L + laser vermelho 660nm (TFD) quando comparando os terços radiculares, onde o terço apical apresentou maiores valores de resistência de união em relação ao terço médio (P=.0302). Nos demais grupos e terços não houve diferença estatística significante (P>.05). Quanto a morfologia da interface adesiva foi possível observar uma menor penetração do cimento obturador no grupo AM100L. Conclusão: Pode-se concluir que o uso de TFD com o fotossensibilizador azul de metileno na concentração de 50 mg/L não alterou negativamente a resistência de união do cimento obturador MTA Fillapex na dentina intrarradicular(AU)

Introduction: Photodynamic therapy (PDT) is used as an adjunct to endodontic treatment to enhance microbial reduction in the root canal system. However, studies are lacking on the consequences of the application of the application of PDT on the bond strength of the root canal sealer. Therefore, the objective of this study was to evaluate the influence of photodynamic therapy with methylene blue on the bond strength the root canal sealer using a push-out test, to analyze the fracture pattern of representative samples using scanning electron microscopy (SEM) and the morphology of the adhesive interface of the intraradicular dentin using Confocal Laser Scanning Microscopy (CLSM). Material and Methods: Fifty-five bovine teeth were used to simulate experimental endodontic treatments. Biomechanical instrumentation was performed for all root canals, and the teeth were distributed into 5 groups: control deionized water; methylene blue 50 mg/L (MB50WL); methylene blue 100 mg/L (MB100WL); methylene blue 50 mg/L + red laser 660nm (MB50L) (PDT); and methylene blue 100 mg/L + red laser 660nm (MB100L) (PDT). The push-out bond strength of the root sealer to dentin was measured using a universal testing machine (n=8), representative scanning electron microscopy images were obtained. Images of the morphology of the adhesive interface were obtained using CLSM (n=3). Bond strength data were submitted to the non-parametric Kruskal-Wallis test for comparison between groups and the Friedman test for comparison between thirds (α=.05). Results: Comparing the root thirds, for the methylene blue group with the higher concentration activated by Red Laser, there was significant difference, the apical third presented higher values of bond strength in relation to the middle third (P=.0302). In the other groups and thirds there was no statistically significant difference (P>.05). As for the morphology of the adhesive interface, it was possible to observe a lower penetration of the sealer in the MB100L group. Conclusion: The application of PDT with the photosensitizer methylene blue at a concentration of 50 mg/L, regardless of the activation by red laser, did not alter negatively the bond strength of the MTA Fillapex sealer to intraradicular dentin(AU)