No abstract available.
Dentin

The fracture toughness test is believed as a clinically relevant method for assessing the fracture resistance of the dentinal restoratives. The objectives of this study were to measure the fracture toughness (K1C) and microtensile bond strength of dentin-resin composite interface and compare their relationship for their use in evaluation of the integrity of the dentin-resin bond. A minimum of six short-rod specimens for fracture toughness test and fifteen specimens for microtensile bond strength test was fabricated for each group of materials used. After all specimens storing for 24 hours in distilled water at 37degrees C, they were tensile-loaded with an EZ tester universal testing machin. Statistical analysis was performed using ANOVA and Tukey's test at the 95% confidence level, Pearson's coefficient was used to verify the correlation between the mean of fracture toughness and microtensile bond strength. FE-SEM was employed on fractured surface to describe the crack propagation. Fracture toughness value of Clearfil SE Bond (SE) was the highest, followed by Adper Single Bond 2 (SB), OptiBond Solo (OB), ONE-STEP PLUS (OS), ScotchBond Multi-purpose (SM) and there was significant difference between SE and other 4 groups (p < 0.05). There were, however, no significant difference among SB, OB, OS, SM (p > 0.05). Microtensile bond strength of SE was the highest, followed by SB, OB, SM, OS and OS only showed significant lower value (p < 0.05). There was no correlation between fracture toughness and microtensile bond strength values. FE-SEM examination revealed that dentin bonding agent showed different film thickness and different failure pattern according to the film thickness. From the limited results of this study, it was noted that there was statistically no correlation between K1C and microTBS. We can conclude that for obtaining the reliability of bond strength test of dentin bonding agent, we must pay more attention to the test procedure and its profound scrutiny.
Dentin ; Water

The fracture toughness test is believed as a clinically relevant method for assessing the fracture resistance of the dentinal restoratives. The objectives of this study were to measure the fracture toughness (K1C) and microtensile bond strength of dentin-resin composite interface and compare their relationship for their use in evaluation of the integrity of the dentin-resin bond. A minimum of six short-rod specimens for fracture toughness test and fifteen specimens for microtensile bond strength test was fabricated for each group of materials used. After all specimens storing for 24 hours in distilled water at 37degrees C, they were tensile-loaded with an EZ tester universal testing machin. Statistical analysis was performed using ANOVA and Tukey's test at the 95% confidence level, Pearson's coefficient was used to verify the correlation between the mean of fracture toughness and microtensile bond strength. FE-SEM was employed on fractured surface to describe the crack propagation. Fracture toughness value of Clearfil SE Bond (SE) was the highest, followed by Adper Single Bond 2 (SB), OptiBond Solo (OB), ONE-STEP PLUS (OS), ScotchBond Multi-purpose (SM) and there was significant difference between SE and other 4 groups (p < 0.05). There were, however, no significant difference among SB, OB, OS, SM (p > 0.05). Microtensile bond strength of SE was the highest, followed by SB, OB, SM, OS and OS only showed significant lower value (p < 0.05). There was no correlation between fracture toughness and microtensile bond strength values. FE-SEM examination revealed that dentin bonding agent showed different film thickness and different failure pattern according to the film thickness. From the limited results of this study, it was noted that there was statistically no correlation between K1C and microTBS. We can conclude that for obtaining the reliability of bond strength test of dentin bonding agent, we must pay more attention to the test procedure and its profound scrutiny.
Dentin ; Water

No abstract available.
Dentin* ; Hypersensitivity*

No abstract available.
Adhesives* ; Dentin*

No abstract available.
Adhesives* ; Dentin*

OBJECTIVES: The aims of this study were to conduct a systematic review of the microtensile bond strength (µTBS) of multi-mode adhesives to dentin and to perform a meta-analysis to assess the significance of differences in the µTBS of one of the most commonly used universal adhesives (Scotchbond Universal, 3M ESPE) depending on whether the etch-and-rinse or self-etch mode was used. MATERIALS AND METHODS: An electronic search was performed of MEDLINE/PubMed, ScienceDirect, and EBSCOhost. Laboratory studies that evaluated the µTBS of multi-mode adhesives to dentin using either the etch-and-rinse or self-etch mode were selected. A meta-analysis was conducted of the reviewed studies to quantify the differences in the µTBS of Scotchbond Universal adhesive. RESULTS: Only 10 studies fulfilled the inclusion criteria for the systematic review. Extensive variation was found in the restorative materials, testing methodologies, and failure mode in the reviewed articles. Furthermore, variation was also observed in the dimensions of the microtensile testing beams. The meta-analysis showed no statistically significant difference between the etch-and-rinse and self-etch modes for Scotchbond Universal adhesive (p > 0.05). CONCLUSIONS: Multi-mode ‘universal’ adhesives can achieve substantial bonding to dentin, regardless of the used modes (either etch-and-rinse or self-etch).
Adhesives* ; Dentin* ; Dentin-Bonding Agents

PURPOSE: The aim of this study was to compare the effectiveness of hydroxyapatite containing toothpaste with positive control toothpastes in reducing dentine hypersensitivity. MATERIALS AND METHODS: This clinical trial was a double-blind, randomized, parallel group comparison of two, namely hydroxyapatite containing toothpaste and strontium chloride containing toothpaste. A total of 55 subjects were included in this study. The subjects were given randomly assigned one of the two toothpastes after received tooth brushing instruction at baseline. Some clinical indices(PI, GI, PD), verbal rating score(VRS) for sensitivity to stimulus, the effect in relieving sensitivity and visual analogue scale(VAS) for sensitivity at baseline, week 2, week 4 and week 8 were assessed. All data were evaluated by intention-to-treat analysis. RESULTS: Overall, PI and GI scores were significantly reduced compare baseline in all groups(p<0.05). In addition, there was significant difference in PI at 4 weeks and in GI at 4, 8 weeks between groups. The proportions of subjects relieved sensitivity were 70.4% in experimental group and 57.1% in control group at 8 weeks respectively. The VRS for sensitivity to three kinds of stimuli and VAS for sensitivity decreased according to time, there was no overall difference between two groups(p>0.05). CONCLUSION: This study demonstrated that the new hydroxyapatite containing toothpaste was similarly effective in reducing dentine hypersensitivity with pre-existing benchmark toothpaste.
Dentin ; Dentin Sensitivity ; Durapatite ; Strontium ; Tooth ; Toothpastes

No abstract available.
Dental Porcelain* ; Dentin* ; Dentin-Bonding Agents*

OBJECTIVETo determine the role of 1,25(OH)2D3 on the secondary dentin formation and mineralization of the mice.

METHODSThe differences of the mandible mineralization between the wild-type and 1-alpha-hydroxylase gene knockout mice at 6 weeks old were assessed by hematoxylin-eosin (HE) staining, immunohistochemistry, alkaline phosphatase (ALP) histochemistry staining.

RESULTSThe ratio of caries were increased significantly, while the secondary dentin was reduced significantly, the deposition of type I collagen and osteocalcin on the secondary dentin of occlusion surface was decreased significantly, but the deposition of the Biglycan on the dentin was increased significantly, the active of ALP on the odontoblasts were reduced significantly in 1-alpha-hydroxylase gene knockout mice compared to that in the wild-type littermates.

CONCLUSION1,25(OH)2D3 deficiency lead to a defect in the secondary dentin formation and mineralization and caries of the mice.