High-intensity laser application in Orthodontics

ABSTRACT Introduction: In dental practice, low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated to orthodontic treatment. Objective: The aim of this study is to discuss HILT applications in orthodontic treatment. Methods: This study describes the use of HILT in surgical treatments such as gingivectomy, ulotomy, ulectomy, fiberotomy, labial and lingual frenectomies, as well as hard tissue and other dental restorative materials applications. Conclusion: Despite the many applications for lasers in Orthodontics, they are still underused by Brazilian practitioners. However, it is quite likely that this demand will increase over the next years - following the trend in the USA, where laser therapies are more widely used.

High-intensity laser application in Orthodontics.

INTRODUCTION: In dental practice, low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated to orthodontic treatment. OBJECTIVE: The aim of this study is to discuss HILT applications in orthodontic treatment. METHODS: This study describes the use of HILT in surgical treatments such as gingivectomy, ulotomy, ulectomy, fiberotomy, labial and lingual frenectomies, as well as hard tissue and other dental restorative materials applications. CONCLUSION: Despite the many applications for lasers in Orthodontics, they are still underused by Brazilian practitioners. However, it is quite likely that this demand will increase over the next years - following the trend in the USA, where laser therapies are more widely used.

Effects of laser vs ultrasound on bone healing after distraction osteogenesis: A histomorphometric analysis.

OBJECTIVE: To assess the effects of low-level laser irradiation vs ultrasound irradiation on bone healing after distraction osteogenesis. MATERIALS AND METHODS: Distraction osteogenesis was performed with rapid maxillary expansion devices (Hyrax-Morelli, Sorocaba, São Paulo Brazil) in 24 rabbits (Oryctolagus cuniculus). After a 2-day latency period, the distraction devices were activated for 10 days at a rate of 1 mm/d. Four groups of six animals were treated as follows: (1) control, (2) laser irradiation on the right side, (3) ultrasound irradiation on the right side, and (4) laser irradiation on the right side and ultrasound on the left side. Histomorphometric analysis was used to assess the bone healing area. Analysis of variance was used to perform the statistical analyses. RESULTS: The influence of low-intensity laser associated with ultrasound irradiation on bone healing was statistically significant. The analyses showed the greatest amount of bone healing in the jaws of animals in group 4, which received treatment with both ultrasound and laser. CONCLUSION: This study concluded that bone healing is accelerated with the application of laser irradiation. The greatest effects were observed with combined ultrasound and laser treatment.

Assessment of exogenous pigmentation in colourless elastic ligatures.

INTRODUCTION: The aim of this study was to evaluate colour alteration of transparent elastic ligatures submitted to exogenous pigmentation. METHODS: Forty test specimens were divided into eight groups corresponding to one commercial brand with five test specimens in each group. The test specimens were immersed into coffee and black tea solutions with the purpose of assessing colour alteration using a portable digital spectrophotometer (Vita Easyshade Compact). The surfaces of the ligatures under scanning electron microscope (SEM) at ×30, ×150 and ×20,000 magnification were evaluated with the purpose of observing the differences in porosity of the ligatures. The Kolmogorov-Smirnov test for normality was applied followed by the one-way analysis of variance (one-way ANOVA) and the level of significance adopted was 95%. RESULTS: All the groups showed modified initial colour that was perceptible to the human eye. The brand that showed greater colour alteration, in comparison with its initial colour, was the American® pearl elastic ligature and the ligatures that presented the smallest colour variation were the Ortho-Organizer®. The surface evaluations of the ligatures showed differences with regard to the topography evidencing more porosity in the ligatures that showed greater staining. CONCLUSION: The group that changed colour significantly was the one that presented the highest porosity, and the brand that was the least altered was the one that showed the lowest porosity.

Laser versus ultrasound on bone density recuperation after distraction osteogenesis-a cone-beam computer tomographic analysis.

PURPOSE: To assess the effects of low-level laser versus ultrasound irradiation on bone mineral density after distraction osteogenesis using cone-beam computed tomographic analysis in an experimental study. MATERIALS AND METHODS: Distraction osteogenesis was performed with rapid maxillary expansion devices (Hyrax-Morelli, Sorocaba-São Paulo-Brazil). After a 2-day latency period, the distraction devices were activated for 10 days at a rate of 1 mm/day. Four groups of 6 animals were distributed as follows: 1) control, 2) laser irradiation on the right side, 3) ultrasound irradiation on the right side, and 4) laser irradiation on the right side and ultrasound on the left side. Cone-beam computed tomography was used to determine bone mineral density by measuring the recovery (percentage). Analysis of variance and the Tukey test (P = .05) were used for statistical analyses. RESULTS: The influences of low-intensity laser and ultrasound irradiation on bone mineral density were statistically significant. The analyses showed greater bone mineral density recuperation in the mandibular side with the ultrasound application. CONCLUSIONS: The results of this study suggest an acceleration of bone mineral density after laser and ultrasound irradiation. Ultrasound irradiation showed the greatest effects and the laser power positively influenced the recuperation of the bone density on the side opposite its application, causing a cross reaction or even exacerbating the inherent action of ultrasound irradiation.

Bonding brackets to porcelain--in vitro study.

The aim of this research was to verify, in vitro, the effect of various porcelain surface treatment on the shear strength of orthodontic brackets bonded to porcelain and the mode of fracture after debonding. Eighty-eight samples of metallic supported feldspathic porcelain were randomly divided into four groups according to their surface preparation as follows: the porcelain was maintained intact (GI), roughened with a diamond bur (GII), etched with 10% hydrofluoric acid (GIII), or sandblasted with aluminum oxide (GIV). The specimens were treated with silane (Scotchprime) and brackets were bonded with Concise. Each sample was subjected to a shear load at a crosshead speed of 1 mm/min and a recording was made at the point of failure. Bond strengths, adequate to withstand the application of orthodontic forces, were achieved in all groups. The Kruskal-Wallis statistical test showed no significant differences in bond strength between the groups (p > 0.05). However, many more porcelain fractures occurred on deglazed porcelain. This study indicates that with the appropriate material selection, the silane/composite procedure alone may be adequate for bonding.