Maria Ângela Pita Sobral

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Composite resins might be susceptible to degradation and staining when in contact with some foods and drinks. This study evaluated color alteration and changes in microhardness of a microhybrid composite after immersion in different colored foods and determined whether there was a correlation between these two variables. Eighty composite disks were randomly(More)
OBJECTIVES To investigate the in vitro dentine wear after tooth brushing with a range of nine toothpastes. METHODS 70 bovine dentine blocks (aproximately 1 cm long) were used. Specimens were brushed in vitro with toothpastes with a range of abrasive. All the specimens were submitted to 10,000 brushing cycles with a 200g load. Initial and final weight and(More)
OBJECTIVES To evaluate the erosive potential of orange juice modified by food additives in enamel and dentine. METHODS Calcium lactate pentahydrate (CLP), xanthan gum (XG), sodium linear polyphosphate (LPP), sodium pyrophosphate tetrabasic (PP), sodium tripolyphosphate (STP) and some of their combinations were added to an orange juice. Pure orange juice(More)
This study evaluated and compared in vitro the morphology and mineral composition of dental enamel after erosive challenge in gastric juice and orange juice. Human enamel specimens were submitted to erosive challenge using gastric juice (from endoscopy exam) (n = 10), and orange juice (commercially-available) (n = 10), as follows: 5 min in 3 mL of(More)
OBJECTIVE The purpose of this study was to analyze dentinal surfaces that were exposed to acidic beverages, then treated with Nd:YAG laser and afterwards exposed to acidic beverages again. BACKGROUND DATA Dentin hypersensitivity can result from surface erosion caused by acidic beverages, which exposes and enlarges the dentinal tubules. Nd:YAG laser has(More)
OBJECT The aim of this study was to report the reasons for placement and replacement of direct restorations in private general dental practices in Brazil. METHOD AND MATERIALS Thirty-seven practitioners recorded information regarding 16 consecutive direct restorations placed by themselves in a 4-week period. The information recorded reported the patient's(More)
The purpose of this study was to evaluate clinically the effects of pre-treatments with a 35% hydroxyethyl metacrylate/5% glutaraldehyde dentine desensitizer (Gluma Desensitizer) and a 2% chlorexidine-based cavity disinfectant (Cav-Clean) on postoperative sensitivity. Three premolar teeth with no pain symptoms were selected from each one of 17 patients,(More)
OBJECTIVES This study investigated the radio-opacity of commercially available glass ionomer cements (GICs), flowable resin composites (FRCs) and calcium hydroxide cements (CHCs) and compared this with the radio-opacity of enamel, dentine and aluminium stepwedge. 16 GICs, 8 FRCs and 4 CHCs were analysed. METHODS Three sets of three samples were prepared:(More)
The aim of this study was to define, in vitro, the potential to inhibit secondary caries of restorative materials currently used in dental practice. Standard cavities were prepared on the buccal and lingual surfaces of fifty extracted human third molars. The teeth were randomly divided into five groups, each one restored with one of the following materials:(More)
The aim of this study was to create a synthetic juice (SJ) to be used as a surrogate for natural orange juices in erosion studies, verifying its erosive potential. The SJ was formulated based on the chemical composition of orange juices from different locations. Forty enamel and 40 root dentin specimens were randomly assigned into 4 experimental groups (n =(More)