Effect of ion supplementation of a commercial soft drink on tooth enamel erosion

Acidic soft drinks are potentially erosive for dental hard tissues. This in vitro study evaluated the effect of calcium, fluoride, iron and phosphate, supplemented alone or in combination to a commercial citric acid-based carbonated beverage on dental erosion. Ninety enamel samples (4 x 4 x 3 mm) were randomly allocated to nine groups (n = 10): G1 - pure beverage (control); G2 - with 1 mM Ca; G3 - with 0.047 mM F; G4 - with 1 mM Fe; G5 - with 1 mM P; G6 - with 1 mM Ca and 0.047 mM F; G7 - with 1 mM Ca and 1 mM P; G8 - with 1 mM Fe and 0.047 mM F; and G9 - with 1 mM Ca, 1 mM P, 0.047 mM F and 1.0 mM Fe. The samples were subjected to six pH cycles over a 24-h period. In each cycle, the samples were immersed in pure or modified beverage (1 min) and in artificial saliva (59 min). During the remaining period (18 h), the samples were maintained in artificial saliva. Enamel loss was assessed by profilometry (mm). Data were tested using ANOVA and Tukey`s tests (p < 0.05). Highest enamel losses were observed in the control group (G1) and in the groups containing Fe (G4 and G8). The groups containing Ca (G2 and G6) showed significantly less wear compared to control. In conclusion, the modification of an erosive soft drink with low concentrations of Ca with or without F may reduced its erosive potential.

Effect of 4% titanium tetrafluoride solution on dental erosion by a soft drink: An in situ/ex vivo study

Objective: This in situ/ex vivo study assessed the effect of titanium tetrafluoride (TiF4) on permanent human enamel subjected to erosion. Design: Ten volunteers took part in this study performed in two phases. In the first phase (ERO), they wore acrylic palatal appliances containing two enamel blocks, divided into two rows: TiF4 (F) and no-TiF4 (no-F). During the 1st day, the formation of a salivary pellicle was allowed. In the 2nd day, the TiF4 solution was applied on one row (ERO + F), whereas on the other row no treatment was performed (ERO + no-F). From 3rd until 7th day, the blocks were subjected to erosion, 4x per day. In the 2nd phase (no-ERO), the volunteers wore acrylic palatal appliances containing one enamel block, during 2 days, to assess the effect of TiF4 only (no-ERO + F). Enamel alterations were determined using profilometry (wear), microhardness (%SMHC) tests, scanning electron microscope and microprobe analysis. The %SMHC and wear were tested using ANOVA and Tukey`s post hoc tests (p < 0.05). Results: The mean of %SMHC and wear ( mu m) values ( +/- S.D.) were, respectively: ERO + F -73.32 +/- 5.16(A)/2.40 +/- 0.60(a); ERO + no-F -83.49 +/- 4.59B/1.17 +/- 0.48(b) and no-ERO + F -67.92 +/- 6.16(A)/0.21:E 0.09(c). In microscope analysis, the no-F group showed enamel with honeycomb appearance. For F groups, it was observed a surface coating with microcracks. The microprobe analysis revealed the presence of the following elements (%) in groups ERO + F, ERO + no-F and no-ERO + F, respectively: Ca (69.9, 72.5, 66.25); P (25.9, 26.5, 26.06); Ti (3.0, 0, 5.93). Conclusions: The TiF4 was unable to reduce dental erosion. (c) 2007 Elsevier Ltd. All rights reserved.

Heat Release, Time Required, and Cleaning Ability of Mtwo R and ProTaper Universal Retreatment Systems in the Removal of Filling Material

Introduction: This ex vivo study evaluated the heat release, time required, and cleaning efficacy of MTwo (VDW, Munich, Germany) and ProTaper Universal Retreatment systems (Dentsply/Maillefer, Ballaigues, Switzerland) and hand instrumentation in the removal of filling material. Methods: Sixty single-rooted human teeth with a single straight canal were obturated with gutta-percha and zinc oxide and eugenol-based cement and randomly allocated to 3 groups (n = 20). After 30-day storage at 37 degrees C and 100% humidity, the root fillings were removed using ProTaper UR, MTwo R, or hand files. Heat release, time required, and cleaning efficacy data were analyzed statistically (analysis of variance and the Tukey test, alpha = 0.05). Results: None of the techniques removed the root fillings completely. Filling material removal with ProTaper UR was faster but caused more heat release. Mtwo R produced less heat release than the other techniques but was the least efficient in removing gutta-percha/sealer. Conclusions: ProTaper UR and MTwo R caused the greatest and lowest temperature increase on root surface, respectively; regardless of the type of instrument, more heat was released in the cervical third. Pro Taper UR needed less time to remove fillings than MTwo R. All techniques left filling debris in the root canals. (I Endod 2010;36:1870-1873)

Tooth abnormalities and soft tissue alterations in patients with G/BBB syndrome

OBJECTIVE: The G/BBB syndrome is an X-linked recessive disorder characterized by eye anomalies, laryngotracheoesophageal cleft, congenital heart disease, genitourinary anomalies and gastrointestinal disorders. Patients may also present cleft lip and palate, high-arched palate and thin upper lip. This study aimed to investigate the occurrence of tooth abnormalities and soft tissue changes in patients with G/BBB syndrome. DESIGN: Cross-sectional. SUBJECTS AND METHODS: Twenty-one patients with G/BBB syndrome were analyzed as to the presence of tooth abnormalities and soft tissue alterations. MAIN OUTCOME MEASURES: The prevalence of tooth agenesis and supernumerary teeth was compared to patients without morphofunctional alterations, matched for gender and age. RESULTS: All patients had complete cleft lip and palate; 95.23% of patients presented tooth abnormalities, mainly hypoplastic alterations, with predominance of alterations of number, followed by alterations of structure, shape and position. The frequency of tooth agenesis and supernumerary teeth was significantly higher compared with the control group; 11 patients presented incisiform supernumerary teeth in the mandibular anterior region. Ankyloglossia was observed in 11 of 21 patients. CONCLUSION: The presence of mandibular anterior supernumerary teeth and ankyloglossia should be investigated in the clinical evaluation of patients with suspected diagnosis of the G/BBB syndrome. Oral Diseases (2008) 14, 747-753

Tooth abnormalities and soft tissue changes in patients with velocardiofacial syndrome

Objective. The objective of this study was to investigate the prevalence of tooth abnormalities and soft tissue changes in patients with velocardiofacial syndrome. Study design. Twenty-six patients with velocardiofacial syndrome were examined to investigate the presence of tooth abnormalities and soft tissue alterations. The occurrence of tooth agenesis and supernumerary teeth was compared to patients without morphofunctional alterations, matched for gender and age. Results. Of all patients, 76.92% exhibited at least one tooth abnormality, with predominance of hypoplastic alterations, especially represented by hypodevelopment of the lingual cusp of mandibular first premolars and enamel opacities. The occurrence of tooth agenesis and supernumerary teeth was similar in both study and control groups. Conclusion. the present results suggest an association between hypodevelopment of the lingual cusp of mandibular first premolars and enamel opacities, yet these findings still require corroboration. Future studies should further investigate these aspects in larger samples compared to control groups, as well as employing molecular genetics techniques.

Influence of interimplant distances and placement depth on peri-implant bone remodeling of adjacent and immediately loaded Morse cone connection implants: a histomorphometric study in dogs

Objectives The aim of this study was to histomorphometrically evaluate the influence of interimplant distances (ID) and implant placement depth on bone remodeling around contiguous Morse cone connection implants with `platform-shifting` in a dog model. Material and methods Bilateral mandibular premolars of six dogs were extracted, and after 12 weeks, each dog received 8 implants, four placed 1.5 mm subcrestally (SCL) on one side of the mandible and four placed equicrestally (ECL) on the other side, alternating the ID of 2 and 3 mm. The experimental groups were SCL with IDs of 2 mm (2 SCL) and 3 mm (3 SCL) and ECL with IDs of 2 mm (2 ECL) and 3 mm (3 ECL). Metallic crowns were immediately installed. After 8 weeks, the animals were euthanized and histomorphometric analyses were performed to compare bone remodeling in the groups. Results The SCL groups` indices of crestal bone resorption were significantly lower than those of ECL groups. In addition, the vertical bone resorption around the implants was also numerically inferior in the SCL groups, but without statistical significance. No differences were obtained between the different IDs. All the groups presented similar good levels of bone-to-implant contact and histological bone density. Conclusion The subcrestal placement of contiguous Morse cone connection implants with `platform shifting` was more efficient in preserving the interimplant crestal bone. The IDs of 2 and 3 mm did not affect the bone remodeling significantly under the present conditions. To cite this article:Barros RRM, Novaes AB Jr., Muglia VA, Iezzi G, Piattelli A. Influence of interimplant distances and placement depth on peri-implant bone remodeling of adjacent and immediately loaded Morse cone connection implants: a histomorphometric study in dogs.Clin. Oral Impl. Res. 21, 2010; 371-378.doi: 10.1111/j.1600-0501.2009.01860.x.