Effects of diode laser therapy for the management of peri-implantitis

Abstract

Purpose of Study The efficacy of diode laser treatment for peri-implantitis remains poorly defined. Surface change, heat increase, and bacterial control following irradiation of titanium implants by diode lasers need to be investigated. The purpose of this study was to evaluate the effectiveness and safety of diode laser on peri-implantitis through laboratory and biological experiments. Materials and Methods A diode laser of 808nm wavelength which could output on both continuous and pulse modes was used. Titanium implant of sandblast large grit and acid-etching (SLA) surface was placed on cow bone, and the laser temperature was measured by connecting a sensor on the mesial, distal, buccal and lingual sides. Peri-implantitis was induced by placing SLA-treated titanium screw(SLA-TS) ligated with floss silk on the palate of a 7-weeks-old Sprague Dawley rat. The experimental groups were untreated group, SLA-treated titanium screw implant group, peri-implantitis induction group, diode laser treatment on induced peri-implantitis group. The groups were observed via scanning electron microscope (SEM) and the bacterial count was measured. The level of oral bacterial growth was examined through polymerase chain reaction (PCR). Three premolars were extracted from the mandible of an adult, male beagle, and pretreated implant was placed on the extraction area after a 3 months recovery period. The experimental groups were group with unpretreated implant surface and bone defect site unfilled with Bio-Oss®, group with unpretreated implant surface but bone defect site filled with Bio-Oss®, group pretreated with laser then filled with Bio-Oss®, group pretreated with 0.5% chlorhexidine and filled with Bio-Oss®, group pretreated with iBrush® and filled with Bio-Oss®. The groups were observed and measured by index measurement on implant stability, microtomography and histomorphometry with undecalcified ground sections. Results When the temperature was measured on the cow bone, 808nm diode laser showed an increase by an average of 3.1℃. When PCR was observed after diode laser treatment on the peri-implantitis SD rat model, bacterial reduction by the diode laser treatment was confirmed on the 4th day. As a result of bacterial counting, the number of bacteria decreased effectively in the groups treated with 808nm diode lasers. In the beagle bone regeneration experiment, Untreated but filled Bio-Oss® group better than all the groups. In the experiment, not much re-osseointegration was observed in the laser irradiation group as the untreated group in the implant stability index, microtomography, and histomorphometrical analysis. However, the diode laser treatment showed similar results as chlorhexidine and iBrush® treatment. When the untreated group which was not filled Bio-Oss® was compared to the filled group, there was a significant difference in bone regeneration effect, but there was no statistical significance. Conclusion When the 808nm diode laser was irradiated on the titanium screw, no physical change was observed on the SLA surface. The temperature of the surrounding bone tissue was increased 2.3-3.4℃ when it was irradiated. Bacterial elimination from the SLA-TS surface of SD rat was effective. As a result of comparison between each experimental groups after 808nm diode laser treatment, bone regeneration was observed same as other experimental groups. It was considered that the 808nm diode laser may be effective in peri-implantitis treatment.