Análise histológica comparativa do reparo ósseo em osteotomias realizadas por laser de Er:Yag e broca cirúrgica, submetidas à laserterapia de baixa potência

• Autor(a) principal: Mello, Elaine Duarte Artuso de
• Data de Publicação: 2006
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional PUCRS
• Texto Completo: http://hdl.handle.net/10923/416
• topic: ODONTOLOGIA; LASER - TERAPIA; LASER DE BAIXA INTENSIDADE; REPARAÇÃO ÓSSEA (ODONTOLOGIA); LASER - ODONTOLOGIA; OSTEOTOMIA; CIRURGIA BUCOMAXILOFACIAL; RATOS - EXPERIÊNCIAS

The aim of this study was to compare the bone repair process after osteotomies performed in tibiae of the rats with the Er:YAG laser (2. 94 μm wavelength) and the low-speed bur drilling, under irrigation, submitted to low-level laser therapy (LLLT), diode laser (InGaAlP and GaAIAs), of the 685 and 830 nm wavelengths. Fifty-four Wistar rats were used for this study. The animals were divided in six groups: Group I, osteotomy with Er:YAG; Group II, osteotomy with Er:YAG and LLLT of the 685 nm; Group III, osteotomy with Er:YAG and LLLT of the 830 nm; Group IV, osteotomy with a low-speed bur; Group V, osteotomy with a lowspeed bur and LLLT of the 685 nm; Group IV, osteotomy with a low-speed bur and LLLT of the 685 nm. The Er:YAG laser was used Q-Switch, no contact mode, 10 Hz, 500 mJ. Three animals of each group were killed at 7, 14 and 21 days postoperative. The obtained specimens were stained by hematoxilyn and eosin and analyzed under light microscopy. At seven and fourteen days after surgery, the Groups of the Er:YAG laser presented a better condition of the bone repair as compared to others groups of the osteotomies with low-speed bur. The Er:YAG laser successfully promoted the ablation of the bone tissue, but caused a thermal damage at the margins of the osteotomies. The Er:YAG laser promoted an altered thin layer of the tissue, composed of a darkly stained tissue compatible with char tissue, observed close to the cortical bone. Next to the char layer an amorphous tissue with no defined structure, performed by modified tissue, was observed. The mean thickness of the altered tissue was of 25 μm (±8. 7). The groups submitted to low-speed bur drilling dit not present any altered tissue in the margins of the osteotomies. At 21 days postoperative the histological features of the six groups were very similar, although the altered tissues (char and amorphous) can still be seen in the cavity margins of the osteotomies performed with the Er:YAG. The LLLT of the 685 nm promoted a more organized and faster pattern of the bone repair, as compared to the groups that used the LLLT of the 830 nm wavelength.