Effectiveness of resin-based materials against erosive and abrasive enamel wear.

OBJECTIVE: The objective of this study was to test the effectiveness of resin-based materials against erosive enamel wear under erosive and abrasive challenges by orange juice and tooth brushing. METHODS: Fifty enamel specimens from third molars were assigned to five groups: ICON resin infiltration with no etching (ICON-NE), ICON resin infiltration with 15 % HCl etching (ICON-AE), Seal & Protect sealant (S&P), Tetric EvoFlow (TEF), and control. Erosive lesions were first created on enamel, then treated with resin-based materials. Erosive and abrasive challenges by orange juice and tooth brushing were repeated after treatments. Erosive wear of the treated areas was measured with 3D scanning microscopy, and data were analyzed using ANOVA and paired t tests. RESULTS: Treatments with ICON, S&P, and TEF created a protective material coating of 4.5 ± 1.9 µm, 44.3 ± 8.1 µm, and 84.6 ± 15.7 µm in thickness on the lesion surfaces, respectively. After 15 cycles of erosive and abrasive challenges, enamel or material losses were 21.9 ± 2.3 µm for control, 24.5 ± 4.0 µm for ICON-NE, 24.6 ± 7.4 µm for ICON-AE, 11.2 ± 4.1 µm for S&P, and 3.9 ± 1.9 µm for TEF, respectively. The protective coatings were completely lost in the ICON infiltration groups but remained intact in both the S&P and TEF groups after erosive and abrasive challenges. CONCLUSION: In contrast to a resin sealant and a flowable composite, ICON infiltration resin was not effective in protecting enamel surfaces from erosive and abrasive wear. CLINICAL RELEVANCE: Sealant and flowable composite resin may create protective coatings on eroded enamel surfaces and prevent further tissue loss.

Ethics in a postgraduate proqram.

Experiences with residents in a general practice residency parallel the recent literature on academic integrity among dentists. Based on this background, a planned integrated ethics and professionalism program is outlined for the University of Rochester School of Medicine and Dentistry.

Protective effects of resin sealant and flowable composite coatings against erosive and abrasive wear of dental hard tissues.

OBJECTIVES: To test the effectiveness of sealant and flowable composite coating on eroded enamel, dentin and cementum under erosive/abrasive challenges in vitro. METHODS: A total of 108 tissue sections (36 each for enamel, dentin and cementum) from third molars were assigned to three groups: Seal & Protect sealant (S&P), Tetric EvoFlow composite (TEF) and control. Erosive/abrasive lesions were created on each specimen by citric acid and brushing with toothpaste. S&P and TEF were applied to the lesions and subjected to erosive/abrasive cycling included 24 cycles of immersion in citric acid (pH 3.6) for 60min, followed by remineralization for 120min and brushing with toothpastes for 600 strokes at 150g. Erosive wear of materials or dental tissues were measured with 3D scanning microscopy and data were analyzed using ANOVA. RESULTS: Treatments with S&P and TEF created a protective material coating of 42.7±17.8µm and 150.8±9.9µm in thickness, respectively. After 24 cycles of erosive/abrasive challenges, tissue losses were -346.9±37.3µm for enamel, -166.5±26.3µm for dentin and -164.7±18.2µm for cementum in untreated controls, as compared to material losses of -24.4±3.3µm for S&P, and -10.8±4.4µm for TEF, respectively. Both S&P and TEF were effective in protecting enamel, dentin and cementum against erosive tooth wear (p<0.01). S&P exhibited faster wear than TEF (p<0.01) and showed spotted peeling in a third of the specimens. TEF remained intact on all three types of dental tissues at the end of the 24 cycles of erosive/abrasive challenges. CONCLUSIONS: A thin coating of flowable composite resin 150µm in thickness may provide long-term protection against erosive/abrasive tooth wear. Resin sealant may provide adequate protection for dental hard tissues in short-term and may require repeated applications if long-term protection is desired.

Patient preference: conventional rotary handpieces or air abrasion for cavity preparation.

It has been suggested that patients should accept the use of the air abrasion technique over the conventional handpiece due to the reduced need for anesthesia. Technologies for both air abrasion and the conventional rotary handpiece have, in recent decades, seen major improvements, but there are no recent scientific publications that evaluate the patient's preference for these two technologies when performing a cavity preparation. This study determined the patient's preference for air abrasion or the rotary handpiece for removing occlusal fissure carious lesions in mandibular premolars. Ten healthy subjects 18 years of age or older were recruited from the General Dentistry Clinic of the University of Rochester Eastman Dental Center, with fissure caries at a DEJ depth of similar size (determined by radiographs and clinical examination) in any two mandibular premolars in opposite quadrants. Within each subject, the two methods of caries removal were randomly assigned. In one premolar, air abrasion was used for cavity preparation, and in the other premolar, a conventional rotary handpiece was used. At each visit prior to treatment, the patients were instructed to complete the Emotional Status (ES) questionnaire (SUNY University at Buffalo Craniofacial Pain Clinic) to assess differences in their emotional status between appointments. At each appointment, when the restorative treatment was completed, patients were instructed to rate their pain on the Visual Analogue Scale (VAS). A technique preference questionnaire was given after the second appointment. The subjects rated the perception of pain as significantly lower (p < 0.05) when using air abrasion (6.0 mm versus 29.6 mm). All of the patients preferred air abrasion over conventional rotary handpieces. None of the patients required anesthesia and there was no indication that the emotional status influenced the result. Air abrasion was the preferred method of cavity preparation when removing fissural caries in mandibular premolars and most subjects did not experience any pain when air abrasion was used.

Effect of thickness of flowable resins on marginal leakage in class II composite restorations.

Despite limited scientific evaluation, there is an increased use of low elastic modulus flowable resin composite (FRC) as a stress-relieving gingival increment in Class II restorations. This study compared marginal leakage in preparations with gingival margins in enamel or dentin/cementum (sub-CEJ and supra-CEJ) after FRC was used as a gingival increment to hybrid resin composite used alone. In addition, the extent of leakage around restorations with or without the use of FRC gingival increments when light curing the resin composites from occlusal direction only or buccal, lingual and occlusal directions was compared. Sixty extracted human molars were prepared with two identical Class II (MO and OD) preparations (30 were 1 mm sub-CEJ and 30 were 1 mm supra-CEJ) and randomly assigned to six groups. After etching, dentin-bonding agent was applied to all prepared tooth surfaces according to the manufacturer's specifications. One of three different thicknesses of FRC (0.5 mm, 1 mm or 2 mm) was placed on the gingival floor, cured and a hybrid resin composite was placed occlusally to complete the restoration. The control preparation on each tooth was restored in the same manner, except that a hybrid resin composite was used for both the gingival and occlusal increments. The restored teeth were thermocycled (300 cycles), then immersed in 50% silver nitrate prior to the hemi-section and measured for leakage under a light microscope. The data were evaluated using paired measures analysis of variance (ANOVA). Most of the occlusal margins showed no leakage, while almost every gingival margin demonstrated some silver nitrate penetration regardless of whether it was located sub or supra-CEJ, although significantly less leakage was found in restorations with supra-CEJ margins (p=0.0001). Among supra-CEJ restorations, there was a pronounced reduction in leakage as FRC thickness increased (p=0.0005). In the teeth restored with the gingival-margin located supra-CEJ, the 2 mm thickness FRC gingival increment showed significantly less leakage (p<0.01) compared with the 0.5 mm thickness of FRC gingival increment. The direction of the curing light did not affect the extent of leakage (p>0.05). The use of FRC material as a gingival increment sub-CEJ in posterior hybrid resin restorations produced no significant difference in leakage (p>0.05). The results of this study indicated that restorations located supra-CEJ (with gingival margins in enamel) with 2 mm thick FRC gingival increments demonstrated significantly less leakage than did those with 0.5 mm FRC. When the margin of the restoration was located sub-CEJ (in dentin/cementum), neither the thickness nor the presence of FRC as a gingival increment significantly influenced the marginal leakage.

Fluoride release and anti-erosive effects of dentifrices containing PVM/MA copolymers.

OBJECTIVE: To evaluate fluoride release from dentine discs and study the effects of dentine tubule occlusion and erosion prevention of dentifrices containing fluoride and PVM/MA copolymers in a cycling erosive challenge model. METHODS: Human dentine discs, 15 in each group, were eroded by 1.0% citric acid and treated by ProNamel(®) (PRN, 1450ppm fluoride), Colgate(®) Total Sensitive (CTS, 1100ppm fluoride), a prototype dentifrice containing 5000ppm fluoride and 2% PVM/MA copolymers (PVD) and distilled water (control). Fluoride release from each dentine disc was evaluated every 2h in a 12-h period. For cycling erosive challenges, dentine discs were treated by dentifrice slurries twice daily, followed by immersion in saliva and erosive challenges by orange juice. Dentine discs were stored in saliva between treatment cycles and the cycling erosive challenges were repeated for 15 days. On days 5, 10, and 15, size of dentine tubule openings and level of dentine tubule occlusion were evaluated with a 3D scanning microscope. RESULTS: PVD released more fluorides than other dentifrices in a 12-h period (p<0.05). CTS released more fluorides than PRN at 2, 4, 6, and 8h following a single application (p<0.05). The size of the dentine tubules was smaller and the number of occluded dentine tubules was greater in the CTS and PVD groups than those in the control and PRN groups on day 15 of the erosive challenges. CONCLUSION: Bioadhesive PVM/MA copolymers facilitate fluoride retention and release from dentine discs, and promote dentine tubule occlusion and erosion prevention when combined with hydrated silica particles.

Effects of common beverage colorants on color stability of dental composite resins: the utility of a thermocycling stain challenge model in vitro.

OBJECTIVES: To study the color stability of dental composite resins using a thermocycling stain challenge model accounting for the complex effects of oral environment and tooth brushing. METHODS: Composite resin discs were made from Filtek Supreme Ultra (FiltekSU), TPH3 and Renamel, and subjected to thermocycling challenges in warm coffee (55 °C/pH 5.2) and a cold tea and fruit juice mixtures (5 °C/pH 3.6) for a total of 1000 cycles with 30 seconds dwell time in each solution per cycle. Color was assessed in the CIELAB color space using a Crystaleye dental spectrophotometer before and after thermocycling, and after brushing vigorously for 3 min. The thermocycling stain challenge was repeated for a second 1000 cycles and the discs were brushed again. Color changes were compared among the 3 groups using Kruskal-Wallis test. RESULTS: All 3 groups showed statistically significant color changes after stain challenge, with ΔE* as 5.74 for FiltekSU, 3.21 for TPH3 and 2.52 for Renamel. Color change was more significant in FiltekSU than in TPH3 and Renamel (p<0.05). After brushing, color recovered mostly to its original CIELAB values in TPH3 and Renamel but less so in FiltekSU. The second round of thermocycling stain challenge resulted in color changes in FiltekSU that largely could not be removed by vigorous brushing. CONCLUSIONS: Color stability of FiltekSU is inferior to that of TPH3 and Renamel. The thermocycling stain challenge model can potentially differentiate surface staining that can be removed by brushing from true discoloration of the material that is refractory to oral hygiene procedures.

Rapid quantitative determination of C-reactive protein at chair side in dental emergency patients.

OBJECTIVES: The objective of this study was to quantitatively determine, at chair side, the serum C-reactive protein (CRP) levels in dental emergency patients. STUDY DESIGN: Quantitative CRP test was performed at chair side in 40 patients with acute alveolar abscess (AAA), acute periodontal abscess (APA), and alveolar osteitis (AO) at the time of dental emergency treatment and 1 week after. CRP levels were compared between groups and before and after treatments using ANOVA and Fisher's Exact tests. RESULTS: Serum CRP levels were greater than 5 mg/L in 30 (75%) of the 40 patients. At 1-week follow-up, the decline in CRP levels was evident in the AAA group (P < .05), but not statistically significant in the APA and AO groups (P > .05). CONCLUSION: Serum CRP levels are often elevated in patients with odontogenic infections and postoperative complications. Rapid reduction in serum CRP levels was likely to occur following successful treatment of AAA, but less likely to occur in APA and AO.

Effectiveness of antibiotic prophylaxis in third molar surgery: a meta-analysis of randomized controlled clinical trials.

PURPOSE: We conducted a synthetic quantitative review of the published clinical trials on the effectiveness of antibiotic prophylaxis in third molar surgery. MATERIALS AND METHODS: Electronic databases were searched for randomized controlled trials. The primary outcome variables included alveolar osteitis (AO) and surgical wound infection. The extracted data were analyzed using a meta-analytical program with a random-effect model. Number needed to treat (NnT) was calculated. RESULTS: A total of 2,932 patients randomized in 16 clinical trials reported AO as an outcome. AO occurred in 84 of 1,350 patients in the treatment group, a frequency of 6.2%; and in 228 of 1,582 patients in the control group, a frequency of 14.4%. Systemic antibiotic therapy was effective in reducing the risk of AO (odds ratio [OR], 2.175) with an NnT of 13. A total of 2,396 patients randomized in 12 clinical trials reported wound infection as an outcome. Wound infection occurred in 44 of 1,110 patients in the treatment group, a frequency of 4%; and in 78 of 1,286 patients in the control group, a frequency of 6.1%. Systemic antibiotic therapy was effective in reducing the risk of wound infection (OR, 1.794) with an NnT of 25. Antibiotics reduced the risk of AO and wound infection only when first dose was given before surgery. CONCLUSIONS: Systemic antibiotics given before the surgery were effective in reducing the frequencies of AO and wound infection after third molar surgery.

Patient-fabricated denture prostheses: a clinical report.

This article describes 2 patients who presented with self-made dentures. Each patient had a different motivation for avoiding professional dental treatment. One patient made her own denture because she could not afford dental care, while the other could afford such care but avoided treatment due to a dental phobia. A discussion of diagnosis and treatment planning is presented for each situation.

The effect of two different coatings on the surface integrity and softness of a tissue conditioner.

STATEMENT OF PROBLEM: When they are used to treat inflamed, irritated, or distorted tissues or in implant therapy, tissue conditioners are required to function over relatively long time periods. Most presently available materials have a short life span (3 to 4 days). PURPOSE: This study evaluated the effects of 2 different coatings on the surface integrity and softness of a tissue conditioner over a 4-week period. MATERIAL AND METHODS: Ten subjects with a complete maxillary denture and a functioning mandibular dentition were included in the study. Each maxillary denture had 3 troughs filled with a tissue conditioner (Coe Comfort). One trough was coated with Monopoly and one with Permaseal; the third trough was left uncoated (control). The specimens were tested at insertion and at 1 week, 2 weeks, and 4 weeks post-insertion for softness with a durometer and for surface integrity with a scanning electron microscope. Statistical differences were determined with analysis of variance (P<.05). RESULTS: At the end of 4 weeks, the mean and standard deviation of softness on the ASTM scale was 85.1 (4.2) for the control, 81.6 (3.9) for Monopoly, and 77.9 (5.0) for Permaseal. The difference between the control and Permaseal was significant (P<.0042). Qualitatively, SEM analysis indicated that the control deteriorated by the end of the first week, whereas both Monopoly and Permaseal coatings remained intact for up to 2 weeks. All groups showed some conditioner deterioration by 4 weeks. The tissues under the denture-bearing areas remained healthy during the study period. CONCLUSION: Within the limitations of this study, the application of Permaseal or Monopoly coatings significantly reduced the loss of tissue conditioner softness. Permaseal-coated conditioner remained the softest over the length of the study.