Efficacy of Photoinduced Photoacoustic Streaming and Diode Laser Irrigation Techniques on Smear Layer Removal, Sealer Penetration and Push-out Bond Strength.

Introduction: The present study aimed to test the efficiency of photoinduced photoacoustic streaming using 2940 nm Er: YAG laser and 980 nm diode laser agitation on smear layer removal, sealer penetration and push-out bond strength. Methods: Sixty single canaled human permanent teeth were collected for this study. Specimens were grouped into three experimental groups (20 teeth in each group), depending on the activation protocol used for final irrigation: Group I (needle agitation), group II (980nm diode laser agitation) and group III (photon induced photoacoustic streaming (PIPS) using 2940 nm Er: YAG laser. The quantity of irrigant was standardized in all groups to 4 ml. The irrigant was activated for 40 seconds in different groups under continuous flow. Two teeth from each group were used to check the smear layer removal, and then the remaining teeth in each group were randomly divided into three equal experimental subgroups according to methods of evaluation used: subgroup A: Sealing ability evaluated by dye penetration method; subgroup B: SEM for sealer penetration; and subgroup C: Push-out bond strength assessed by the universal test machine. Results: As regards smear layer removal, results showed that the PIPS group had opened dentinal tubules, followed by the diode laser group, while the least cleaning effect was found in the Side-vented needle group. As for Sealing ability and dye penetration, a statistically significant difference was found between all of the three groups, with the Er:YAG laser (PIPS) having the best sealing ability and sealer penetration. Push-out bond strength results showed no statistically significant difference between diode and Er:YAG groups, with a significant difference between each of them and the Side-vented needle group. Conclusion: Using the diode or Er:YAG laser (PIPS) for irrigant activation led to better irrigant penetration and smear layer removal which subsequently led to obvious sealer penetration, better sealing, and strength properties of endodontic treated teeth.

Experimental nano calcium aluminate/tri calcium silicate root repair: Synthesis, physical and mechanical properties compared to mineral trioxide aggregate and Biodentine / Reparo radicular experimental de nano aluminato de cálcio/silicato de tri cálcio: Síntese, propriedades físicas e mecânicas em comparação com agregado de trióxido mineral e Biodentine

Objective: Endodontic perforation is a challenging mishap that should be repaired with a biocompatible material, Mineral trioxide aggregate (MTA) and Biodentine are the most commonly used repair materials. However, these materials are expensive, (MTA) has prolonged setting time and difficult manipulation. The purpose of this study is to prepare the experimental nano calcium-aluminate/tri-calcium-silicate (CA/C3S) material and comparing its physical properties with biodentine and MTA, to evaluate the experimental material eligibility to compete the commercial repair materials. And to perform part two (animal study) that will evaluate the cytotoxicity, the biocompatibility and the efficacy of (CA/C3S) in furcal perforation repair compared to diode laser. Material and Methods: A mixture of calcium carbonate and aluminum oxide was used to formulate calcium aluminate phase (CA), tri-calcium-Silicate phase (C3S) was formulated by firing of calcium carbonate and quartz. The produced powders were investigated by X-ray diffraction, then (CA) and (C3S) mixed with water.(CA/ C3S) compared with MTA and biodentine for setting-time, micro-hardness, dimensional-stability and solubility. Results: Mean setting time of (CA/C3S) was (32.70±0.75min) which is significantly higher than MTA and Biodentine. The Mean microhardness of (CA/C3S) was (56.50±7.41VHN) which has no statical difference with MTA and Biodentine. Solubility results showed weight increase for (CA/C3S) as following (6.29±3.05)and loss of weight for MTA and Biodentine. The percentage of change in dimensions for(CA/C3S) increased as following (0.64±0.78) while decreased for MTA and Biodentine. Conclusion: The experimental (CA/C3S) material showed good microhardness, dimensional stability and acceptable setting time that could be improved in further work (AU)

Objetivo: A perfuração endodôntica é um percalço desafiador que deve ser reparado com um material biocompatível, Agregado de trióxido mineral (MTA) e Biodentina são os materiais de reparo mais comumente usados. No entanto, esses materiais são caros, (MTA) tem tempo de presa prolongado e difícil manipulação. O objetivo deste estudo é preparar o material experimental de nano aluminato de cálcio/silicato tricálcico (CA/C3S) e comparar suas propriedades físicas com biodentina e MTA, para avaliar a elegibilidade do material experimental para competir com os materiais de reparo comerciais. E realizar a segunda parte (estudo animal) que avaliará a citotoxicidade, a biocompatibilidade e a eficácia do (CA/C3S) no reparo de perfuração de furca em comparação ao laser de diodo.Material e Métodos: Uma mistura de carbonato de cálcio e óxido de alumínio foi usada para formular a fase de aluminato de cálcio (CA), a fase tri-cálcio-silicato (C3S) foi formulada por queima de carbonato de cálcio e quartzo. Os pós produzidos foram investigados por difração de raios X, em seguida (CA) e (C3S) misturados com água. (CA/ C3S) comparados com MTA e biodentina para tempo de presa, microdureza, estabilidade dimensional e solubilidade. Resultados: O tempo médio de presa de (CA/C3S) foi (32,70±0,75min) que é significativamente maior que MTA e Biodentine. A microdureza média de (CA/C3S) foi (56,50±7,41VHN) que não tem diferença estática com MTA e Biodentine. Os resultados de solubilidade mostraram aumento de peso para (CA/C3S) conforme a seguir (6,29±3,05) e perda de peso para MTA e Biodentine. A porcentagem de mudança nas dimensões para (CA/C3S) aumentou como segue (0,64±0,78), enquanto diminuiu para MTA e Biodentine. Conclusão: O material experimental (CA/C3S) apresentou boa microdureza, estabilidade dimensional e aceitável tempo de presa, que pode ser melhorado em trabalhos futuros (AU)

Influence of photobiomodulation and vitamin D on osteoblastic differentiation of human periodontal ligament stem cells and bone-like tissue formation through enzymatic activity and gene expression.

BACKGROUND: (1)Human periodontal ligament stem cells (HPDLSCs) are a unique population of mesenchymal stem cells (MSCs). Recently, the positive effects of photobiomodulation on the regulation of MSCs proliferation and osteogenic differentiation have gained significant attention. This study aimed to assess the effects of photobiomodulation and vitamin D (as an anabolic factor) on HPDLSCs for bone regeneration. METHODS: (2)HPDLSCs were collected, isolated, and characterized and then divided into six groups: groups I and II, control and (10-7 Mol) vitamin D, respectively; group III, irradiation at 1 J/cm2 of 808-nm diode laser; group IV, irradiation at 1 J/cm2 and culture with vitamin D; group V, irradiation at 2 J/cm2, and group VI, irradiation at 2 J/cm2 and culture with vitamin D. Cell viability assay was measured through MTT assay and cell growth curve. Alkaline phosphatase (ALP) enzyme activity and mRNA levels of RUNX2, collagen 1 (Col-1), ALP, and osteonectin were also assessed. RESULTS: (3)Photobiomodulation at 1 and 2 J/cm2 combined with vitamin D significantly promoted HPDLSC proliferation (in MTT assay and cell growth curve results) and osteogenic differentiation (through the gene expression of RUNX2, Col-1, ALP, and osteonectin levels (p < 0.05). CONCLUSION: (4)Laser irradiation at 2 J/cm2 combined with vitamin D3 enhanced osteoblast differentiation and proliferation of cultured HPDLSCs and thus could further substitute bone grafting.

Efficacy of diode laser and sonic agitation of Chlorhexidine and Silver-nanoparticles in infected root canals / Eficácia do laser de diodo e agitação sônica de clorexidina e nanopartículas de prata em canais radiculares infectados

Objective: To assess the efficacy of agitation of chlorohexidine (CHX) and Silver nanoparticles "AgNps" with 810nm diode laser or sonic endoactivator compared to side ­vented needle on infected root canals with Enterococcus "E" Faecalis biofilms. Material and Methods: Sixty-five extracted human premolars with single oval canals were instrumented by protaper system up to F3. Biofilms of E. faecalis were generated based on a previously established protocol. Two teeth were used to check the biofilm formation, then the remaining Teeth were randomly divided into three equal experimental groups according to agitation techniques used: group 1 (810 nm diode laser with 1 watt) , group 2 (sonic endoactivator) and group 3 (Side vented needle). Each group was further divided into three equal subgroups according to the irrigant solution into; subgroup A: chlorohexidine, subgroup B: silver nanoparticles and subgroup C: distilled water: Confocal laser scanning microscopy "CLSM" was used to assess bacterial viability. Data were analyzed by appropriate statistical analyses with P = 0.05. Results: Regarding the activation method, all groups had a significantly high percentage of dead bacteria (P < 0.05). However, Laser was significantly the highest and Endoactivator the least (P < = 0.001). Diode laser agitation of AgNps irrigant showed the highest reduction percentage of bacteria (78.1%) with a significant difference with both CHX and water irrigation, Conclusion: Under the condition of the present study; results reinforced that laser activation is a useful adjunct, 810 nm diode laser agitation of AgNps or chlorhexidine was more effective in disinfection of oval root canals than endoactivator and side vented needle techniques. (AU)

Objetivo: Avaliar a eficácia da agitação de clorohexidina (CHX) e nanopartículas de prata (AgNps) , com laser de diodo de 810 nm ou endoativador sônico, em comparação à agulha de ventilação lateral, em canais radiculares infectados com biofilmes de Enterococcus "E"; Faecalis. Material e Métodos: Sessenta e cinco pré-molares humanos com um único canal oval, extraídos, foram instrumentados pelo sistema protaper até F3. Os biofilmes de E. faecalis foram gerados com base em um protocolo previamente estabelecido. Foram utilizados dois dentes para verificar a formação do biofilme, e os dentes restantes foram divididos aleatoriamente em três grupos experimentais iguais, de acordo com as técnicas de agitação utilizadas: grupo 1 (laser de diodo 810 nm com 1 watt), grupo 2 (endoativador sônico) e grupo 3 (Agulha com ventilação lateral). Cada grupo foi dividido em três subgrupos iguais, de acordo com a solução irrigante; subgrupo A: clorohexidina, subgrupo B: nanopartículas de prata e subgrupo C: água destilada: A microscopia confocal de varredura a laser foi usada para avaliar a viabilidade bacteriana. Os dados foram analisados por análises estatísticas apropriadas com P = 0,05. Resultados: Em relação ao método de ativação, todos osgrupos apresentaram percentual significativamente alto de bactérias mortas (P < 0.05). No entanto, para o laser foi significativamente o mais alto e, para oendoativador, o menos alto (P < = 0.001). A agitação com laser de diodo doirrigante AgNps apresentou a maior porcentagem de redução de bactérias (78,1%), com diferença significativa tanto para irrigação com CHX quanto comágua. Conclusão: Sob as condições do presente estudo; os resultadosreforçaram que a ativação a laser é um complemento útil, a agitação por laserde diodo de 810 nm de AgNps ou clorexidina foi mais eficaz na desinfecção dos canais radiculares ovais do que as técnicas de endoativador e agulha com ventilação lateral. (AU)