A instrumentação periodontal afeta a dentina submetida a radiação ionizante?

Abstract

Background: The non-surgical periodontal therapy in patients undergoing radiotherapy in the head and neck region can have impact on tooth structure. The aim of this study was to evaluate the effects of different scaling protocols on the morphology and roughness of the root dentin substrate influenced by ionizing radiation. Material and Methods: One hundred and thirty extracted bovine incisors were randomly divided into two sub-group: non-irradiated (NIR) and irradiated (IR). They were randomly subdivided according to the type of non-surgical periodontal protocol of intervention (n = 20): NIT: no instrumentation; NIT/PP: prophylaxis with a fine prophylactic paste using a rubber cup coupled with a low-speed rotation device under constant irrigation for 15 seconds; HS: scaling using hand scaling with 15 apical-coronal instrument movements; HS/PP: Hand scaling followed by prophylaxis protocol; US: ultrasonic scaling with 15 apical-coronal cycles; US/PP: ultrasonic scaling followed by prophylaxis protocol. The root dentin surface roughness was measured with a profilometer (Ra/Rz - m) and the morphological of the dentin surfaces were analyzed using scanning eclectic microscopy (SEM). The Ra data were analyzed using two-way ANOVA followed Tukey`s test (α= 0.05). The SEM data was analyzed by Kappa test assessing the inter-observer and ordinal logistic regression was used to analyze the effect of each factor on the scores. Results: The PP protocol had significant the Ra and Rz values after the types of scaling, regardless of radiotherapy. The US had significant higher Ra and Rz values regardless of radiotherapy. NIr presented the most pronounced Ra increasing values, and the prophylaxis has effect only when the US protocol was used. For Ir groups prophylaxis has effect in both protocols. SEM results showed a moderate concordance among the evaluators was observed (overall Kappa = 0.443). The score levels were not influenced by the substrate protocol. Ordinal logistic regression showed that both HS and US resulted in higher scores than NIT, irrespective of IR presence. Conclusions: The prophylaxis reduced the scores levels for all groups. Prophylaxis alone did not significantly change the Ra parameter of the dentin substrate irradiated or not.