Photobiomodulation and Inorganic Bovine Bone in Guided Bone Regeneration: Histomorphometric Analysis in Rats.

The objective of this study was to evaluate the efficacy of photobiomodulation in the bone regeneration of critical-sized defects (CSD) filled with inorganic bovine bone associated or not with collagen membranes. The study has been conducted on 40 critical defects in the calvaria of male rats, divided into four experimental groups (n = 10): (1) DBBM (deproteinized bovine bone mineral); (2) GBR (DBBM+collagen membrane); (3) DBBM+P (DBBM+photobiomodulation); and (4) GBR+P (GBR+photobiomodulation). At 30 days postoperative, the animals were euthanized, and after the tissue had been processed, histological, histometric, and statistical analyses were performed. The analyses have taken into account newly formed bone area (NBA), linear bone extension (LBE), and residual particle area (RPA) as variables. The Kruskal-Wallis test has been performed, followed by the Dwass-Steel-Critchlow-Fligner test for comparison between groups (p < 0.05). When the DBBM+P group was compared to the DBBM group, it was possible to observe significant statistical differences in all the variables analyzed (p < 0.05). The application of photobiomodulation in guided bone regeneration (GBR+P) has shown a decrease in the median value for the RPA variable (26.8) when compared to the GBR group (32.4), with a significant statistical difference; however, for NBA and LBE, the therapy has not provided significant results.

Evaluation of Different Photobiomodulation Therapy Protocols as Adjuncts in the Healing of Bone Defects Grafted with Inorganic Bovine Bone.

PURPOSE: This study evaluated the effect of two photobiomodulation therapy protocols on bone regeneration in criticalsize bone defects grafted with inorganic bovine bone. MATERIALS AND METHODS: A critical-size defect was created in 30 adult male rat calvaria, which were divided equally and randomly into three experimental groups (n = 10): (1) DBBM (deproteinized bovine bone mineral); (2) DBBM + PBMT 4 J (4 J; photobiomodulation therapy; GaAlAs, 730 nm, 100 mW, 140 J/cm2); and (3) DBBM + PBMT 6 J (6 J; GaAlAs, 730 nm, 100 mW, 210 J/cm2). Animals were euthanized after 30 days. The neoformed bone area (NBA), linear bone extension (LBE), and area of the remaining particles (ARP) were evaluated. The data were subjected to nonparametric Kolmogorov-Smirnov test and ANOVA, followed by Tukey post hoc test to identify differences between the groups (P < .05). RESULTS: The 6 J group showed the highest average NBA (48.57% ± 28.22%) and demonstrated a statistically significant difference in NBA and LBE. A higher mean ARP was found in the DBBM group (38.73 ± 6.95) than in the groups irradiated by photobiomodulation therapy, with statistically significant differences (P < .05). CONCLUSION: The 6 J protocol showed the best results, promoting greater bone formation with greater resorption of residual particles.

Fotobiomodulação sistêmica transdérmica: uma revisão de literatura / Transdermal systemic photobiomodulation: a literature review

A fotobiomodulação sistêmica (FBM-S) consiste em uma técnica que utiliza o laser de baixa intensidade no espectro vermelho da luz para irradiação sistêmica. Seus benefícios incluem efeito analgésico, antioxidante sistêmico e anti-inflamatório, ativação de células imunológicas, melhora na cicatrização, vasodilatação e aumento da microcirculação. A técnica original, que utiliza cateter e fibra óptica para irradiação sistêmica, é uma técnica invasiva, por isso a fotobiomodulação sistêmica transdérmica foi desenvolvida como uma alternativa. Assim, o objetivo dessa revisão de literatura é discutir os efeitos, aplicações, protocolos e efeitos colaterais desta terapia modificada. Para tanto, foi realizada uma busca na literatura nas bases de dados Pubmed, Bireme, Embase, Scopus, Science Direct, Web of Science e CENTRAL, sem restrição de idioma no período entre 2010 e 2021. Encontraram-se seis estudos sendo um na área da Odontologia. Os resultados desses estudos sugerem que a FBS-S pode ser utilizada para o tratamento de condições sistêmicas. Em Odontologia, no entanto, a literatura ainda é escassa e mais estudos clínicos randomizados controlados são necessários para comprovar seus efeitos e estabelecer um protocolo clínico para sua utilização.

Systemic photobiomodulation (PBM-S) is a technique that uses low-level laser in the red spectrum of light for systemic irradiation. Its benefits include analgesic, systemic antioxi-dant, and anti-inflammatory effect, activation of immune cells, improved healing, vasodilation, and increased microcirculation. The original technique, which uses catheter and optical fibers for systemic irradiation is an invasive technique. Thus, the transdermal systemic photobiomodulation was developed as an alternative. The purpose of this literature review is to discuss the effects, applications, protocols, and side effects of this modified therapy. A literature search was carried out on Pubmed, Bireme, Embase, Scopus, Science Direct, Web of Science, and CENTRAL databases, with no language restriction in the period be-tween 2010 and 2021. Six studies were found, one in the area of Dentistry. The results of these studies suggest that PBM-S can be used for the treatment of systemic conditions. In Dentistry, however, the literature is still scarce and more randomized controlled clinical trials are needed to prove its effects and establish a protocol for its use.

Evaluation of photobiomodulation therapy associated with guided bone regeneration in critical size defects. In vivo study.

The repair of bone defects raises the interest of investigators in several health specialties. Grafting techniques with bone substitutes and laser therapies have been investigated to replace autogenous bone and accelerate the bone healing process. Objective To evaluate the effect of photobiomodulation therapy (PBMT) associated with guided bone regeneration (GBR) in critical size defects. Material and Methods The study was conducted on 80 male rats (Rattus norvegicus albinus, Wistar) submitted to surgical creation of a critical size defect on the calvaria, divided into eight study groups: group C (control - only blood clot); group M (collagen membrane); group PBMT (photobiomodulation therapy); group AB (autogenous bone); group AB+PBMT; group AB+M; group PBMT+M; group AB+PBMT+M. The animals were killed 30 days postoperatively. After tissue processing, bone regeneration was evaluated by histomorphometric analysis and statistical analyses were performed (Tukey test, p<0.05). Results All groups had greater area of newly formed bone compared to group C (9.96±4.49%). The group PBMT+M (achieved the greater quantity of new bone (64.09±7.62%), followed by groups PBMT (47.67±8.66%), M (47.43±15.73%), AB+PBMT (39.15±16.72%) and AB+PBMT+M (35.82±7.68%). After group C, the groups AB (25.10±16.59%) and AB+M (22.72±13.83%) had the smallest quantities of newly formed bone. The area of remaining particles did not have statistically significant difference between groups AB+M (14.93±8.92%) and AB+PBMT+M (14.76±6.58%). Conclusion The PBMT utilization may be effective for bone repair, when associated with bone regeneration techniques.

Evaluation of photobiomodulation therapy associated with guided bone regeneration in critical size defects. In vivo study

Abstract The repair of bone defects raises the interest of investigators in several health specialties. Grafting techniques with bone substitutes and laser therapies have been investigated to replace autogenous bone and accelerate the bone healing process. Objective To evaluate the effect of photobiomodulation therapy (PBMT) associated with guided bone regeneration (GBR) in critical size defects. Material and Methods The study was conducted on 80 male rats (Rattus norvegicus albinus, Wistar) submitted to surgical creation of a critical size defect on the calvaria, divided into eight study groups: group C (control - only blood clot); group M (collagen membrane); group PBMT (photobiomodulation therapy); group AB (autogenous bone); group AB+PBMT; group AB+M; group PBMT+M; group AB+PBMT+M. The animals were killed 30 days postoperatively. After tissue processing, bone regeneration was evaluated by histomorphometric analysis and statistical analyses were performed (Tukey test, p<0.05). Results All groups had greater area of newly formed bone compared to group C (9.96±4.49%). The group PBMT+M (achieved the greater quantity of new bone (64.09±7.62%), followed by groups PBMT (47.67±8.66%), M (47.43±15.73%), AB+PBMT (39.15±16.72%) and AB+PBMT+M (35.82±7.68%). After group C, the groups AB (25.10±16.59%) and AB+M (22.72±13.83%) had the smallest quantities of newly formed bone. The area of remaining particles did not have statistically significant difference between groups AB+M (14.93±8.92%) and AB+PBMT+M (14.76±6.58%). Conclusion The PBMT utilization may be effective for bone repair, when associated with bone regeneration techniques.

Effect of different salivary exposure times on the rehardening of acid-softened enamel.

This in situ study assessed the effect of different times of salivary exposure on the rehardening of acid-softened enamel. Bovine enamel blocks were subjected in vitro to a short-term acidic exposure by immersion in 0.05 M (pH 2.5) citric acid for 30 s, resulting in surface softening. Then, 40 selected eroded enamel blocks were randomly assigned to 10 volunteers. Intraoral palatal appliances containing 4 enamel blocks were constructed for each volunteer, who wore the appliance for 12 nonconsecutive hours: initial 30 min, followed by an additional 30, and then by an additional 1 hour. For the last additional 10 hours the appliances were used at night, during the volunteers' sleep. Surface hardness was analyzed in the same blocks at baseline, after erosion and after each period of salivary exposure, enabling percentage of surface hardness recovery calculation (%SHR). The data were tested using repeated measures ANOVA and Tukey's test (α = 0.05). Increasing periods of salivary action promoted a progressive increase in the surface hardness (p < 0.001). However a similar degree of enamel rehardening (p = 0.641) was observed between 2 hours (49.9%) and 12 hours (53.3%) of salivary exposure. Two hours of salivary exposure seems to be appropriate for partial rehardening of the softened enamel surface. The use of the intraoral appliance during sleep did not improve the enamel rehardening after erosion.

Effect of different salivary exposure times on the rehardening of acid-softened enamel

Abstract This in situ study assessed the effect of different times of salivary exposure on the rehardening of acid-softened enamel. Bovine enamel blocks were subjected in vitro to a short-term acidic exposure by immersion in 0.05 M (pH 2.5) citric acid for 30 s, resulting in surface softening. Then, 40 selected eroded enamel blocks were randomly assigned to 10 volunteers. Intraoral palatal appliances containing 4 enamel blocks were constructed for each volunteer, who wore the appliance for 12 nonconsecutive hours: initial 30 min, followed by an additional 30, and then by an additional 1 hour. For the last additional 10 hours the appliances were used at night, during the volunteers' sleep. Surface hardness was analyzed in the same blocks at baseline, after erosion and after each period of salivary exposure, enabling percentage of surface hardness recovery calculation (%SHR). The data were tested using repeated measures ANOVA and Tukey's test (α = 0.05). Increasing periods of salivary action promoted a progressive increase in the surface hardness (p < 0.001). However a similar degree of enamel rehardening (p = 0.641) was observed between 2 hours (49.9%) and 12 hours (53.3%) of salivary exposure. Two hours of salivary exposure seems to be appropriate for partial rehardening of the softened enamel surface. The use of the intraoral appliance during sleep did not improve the enamel rehardening after erosion.