Impact of a simplified in situ protocol on enamel loss after erosive challenge

Abstract

This study investigated the effect of the period of use and location of intraoral appliances on enamel surface loss. This randomized, single blind in situ study was conducted in 2 crossover phases based on the period of use, in which maxillary and mandibular appliances were simultaneously worn. Bovine enamel blocks (n = 120) were randomly divided among the studied groups by surface hardness. In each phase, fifteen volunteers used one maxillary appliance and two mandibular appliances for 5 days. Erosive challenge was performed 4X/day by immersion in 0.01 M HCL for 2 minutes. In the continuous phase, the intraoral appliances were worn for 20 hours. In the intermittent phase the appliances were worn for 8 hours and 30 minutes. Enamel loss was determined profilometrically. The discomfort of use of the appliances were evaluated in a questionnaire. Data were analyzed by two-way ANOVA/Tukey’s test and chi-square test (p<0.05). The maxillary appliance promoted higher enamel loss compared to the mandibular one (p<0.001). Intermittent use of appliances resulted in similar enamel loss to the continuous one (p = 0.686). All volunteers preferred to use the maxillary appliance in an intermittent regimen. The intermittent use of maxillary appliance is a simplified reliable protocol appropriated for in situ erosion studies in enamel.

Effect of in situ aspartame mouthwash to prevent intrinsic and extrinsic erosive tooth wear

“…The night before the beginning of each phase, the volunteers wore the intraoral appliances overnight (11.00 until 7.00) to allow formation of acquired enamel pellicle. Thereafter, volunteers wore the appliance for 5 working days from 7.45 to 18.00 (times could vary +/- 30 min) ( 11 ). The experimental procedure was as follows (all times +/- 15 min): at 7.45 the appliance was worn for pellicle formation; at 8.00 and 10.00 the treatment + erosive challenge was performed; at 12.00 the appliance was removed and stored in wet gauze during lunch; at 13.45 the appliance was worn for pellicle formation; at 14.00 and 16.00 the treatment + erosive challenge; and at 18.00 the appliance was removed and stored in wet gauze during night sleep.…”

Eroded enamel rehardening using two intraoral appliances designs in different times of salivary exposure

“…Important scientific data regarding preventive measures for erosion comes from in situ models (6,7). The main advantage of the in situ models is the closely resembling of the natural environment due to the presence of salivary flow and acquired pellicle formation (8).…”

“…Our research group have been studied different types of in situ appliances with a variety of time use, in order to find a protocol that better simulates a patient at risk of developing dental erosion (6,7,11-13). Santos et al (6) investigated the effect of the period of use and location of intraoral appliances on enamel surface loss and have concluded that the intermittent use of appliances resulted in similar enamel loss compared to the continuous use.…”

“…Our research group have been studied different types of in situ appliances with a variety of time use, in order to find a protocol that better simulates a patient at risk of developing dental erosion (6,7,11-13). Santos et al (6) investigated the effect of the period of use and location of intraoral appliances on enamel surface loss and have concluded that the intermittent use of appliances resulted in similar enamel loss compared to the continuous use. When considering all the erosive cycling process (erosive demineralization and rehardening), the enamel blocks located on the maxillary appliance presented significantly higher erosive enamel loss when compared to the enamel blocks of the mandibular appliance (6,7).…”

“…Santos et al (6) investigated the effect of the period of use and location of intraoral appliances on enamel surface loss and have concluded that the intermittent use of appliances resulted in similar enamel loss compared to the continuous use. When considering all the erosive cycling process (erosive demineralization and rehardening), the enamel blocks located on the maxillary appliance presented significantly higher erosive enamel loss when compared to the enamel blocks of the mandibular appliance (6,7). On the other hand, when considering only one event of erosive demineralization there was no difference on the enamel hardness using the maxillary and mandibular appliances by volunteers (12) Another result showed no difference for the re-hardening effect after a single erosive demineralization (11), however is important to emphasize that in this last study the mandibular appliance was made with soft silicon plate, covering the entire lower arch, presenting a completely different design of the appliance used in the present study.…”