Resumen
OBJECTIVES: The aim of this study was to evaluate histologically the immediate effect of two types of air-polishing devices (APDs) on the gingiva. Material and METHODS: The buccal gingiva in four mongrel dogs was exposed to 5, 10 and 20 s of instrumentation, applying a hand-piece type of APD (HP-APD) PROPHY flex and astand-alone type of APD (SA-APD) Jetpolisher in a split-mouth design. Immediately after treatment, the exposed gingiva was excised by sharp dissection and fixed in 10 percent buffered formalin. For each specimen, 15 sections, 20 microm apart, corresponding to the central part of the treated and control untreated gingiva were cut and stained with haematoxylin and eosin. Stained sections were examined histomorphometrically for keratin width and epithelial cell layer (ECL) (prickle and basal cell layers) width. Extent of erosion was expressed as loss of keratin and ECL compared with control. RESULTS: Microscopic examination presented changes in keratin and ECL, including keratin detachment and disruption of the normal ECL architecture. The erosive changes in the gingiva caused by both APD, positively correlated with instrumentation time (p
