Morphological, histochemical, and immunocytochemical study of CO2 and Er:YAG laser effect on oral soft tissues.

OBJECTIVE: The purpose of this study was to investigate the morphological, histochemical, and immunocytochemical changes of the oral mucosa after CO(2) or Er:YAG laser irradiation. BACKGROUND DATA: There have been no comparative reports on CO(2) and Er:YAG laser effects on human oral soft tissues. MATERIALS AND METHODS: Tissue preservation was studied in 40 oral biopsies of young patients obtained by CO(2) and Er:YAG laser surgery. Hematoxylin-eosin and Giemsa stains, PAS/diastase treatment, AE1 and AE2 cytokeratins, MiB1/Ki67, and bcl-2 immunoreactions were performed on the laser cut edges on formalin fixed, paraffin embedded biopsies. RESULTS: CO(2) laser biopsies show blisters, clefts and erosions of the epithelium. Intracellular edema and lengthened nuclei were also seen. The glycogen content results decreased in CO(2) laser biopsies. Good expression for cytokeratins and cell-cycle proliferation markers were found in Er:YAG biopsies, on the contrary the apoptosis marker was better expressed in CO(2) laser biopsies. CONCLUSION: The results suggest that Er:YAG laser may be routinely used in surgery, because of its minimal damage of the epithelial tissue, its low inflammatory reaction, its quicker healing process and its lower risk of scarring.

Combined technique with polyethylene fibers and composite resins in restoration of traumatized anterior teeth.

Traumatized anterior teeth need quick esthetic and functional repair. Esthetic requirements of anterior teeth require the use of composite materials which, in the most complex cases, can be used in association with fibers so as to improve their mechanical resistance. Many kinds of fibers are available. The authors considered parameters such as physical properties, water absorption, ease of cutting and of laying. Polyethylene fibers appear to have the best properties in elasticity, translucency, adaptability, tenaciousness, resistance to traction and to impact. Fifteen children, between 7 and 13 years old, with crown fractures of the anterior sector were treated. In the case of a simple crown fracture, the missing part was restored by polyethylene fibers and composite resins. In the case of a complex crown fracture needing endodontic treatment, the fibers were used as a central core stump in order to restore the dental morphology. At control examinations, the teeth restored by this technique were acceptable, both in function and in aesthetics. Thus, the authors recommend this combined technique for predictable restoration of traumatized anterior teeth.