No abstract

The aim of this in-vitro study was to compare the performance of laser-based (DIAGNOdent, KaVo, Biberach, Germany) and LED-based (Midwest Caries I.D., DENTSPLY Professional, New York, USA) caries detectors in the detection of occlusal caries in permanent molars. The study consisted of 129 visually sound or non-cavitated pits or fissures in 82 extracted permanent human molar teeth. Two trained examiners used the laser-based and LED-based caries detectors to examine the fissures for caries. The teeth were then sectioned at the surfaces suspected of containing occlusal caries and histologically evaluated using stereomicroscopy as a gold standard. Inter-examiner reliability of the caries detector examination was assessed using Cohen's Kappa statistics. The sensitivity, specificity, and accuracy in diagnosing occlusal caries using the two devices were calculated according to appropriate cut-off scores. Receiver operating characteristic (ROC) curves were also determined to compare the diagnostic performance of the devices in occlusal caries diagnosis. The cut-off level of significance was taken as p = 0.005. Cohen's Kappa showed substantial agreement for the laser-based caries detector (0.74), and almost perfect agreement for the LED-based (0.89) caries detector. The specificity of the laser-based device varied from 0.49 to 0.97 at T1 and T2. Its sensitivity varied from 0.33 to 0.65 at T1 and T2. The specificity of the LED-based device varied from 0.48 to 0.56 at T1 and T2. Its sensitivity varied from 0.65 to 0.84 at T1 and from 0.80 to 0.84 at T2. Taking the limitations of the current study into consideration, the DIAGNOdent laser pen was more accurate in determining when teeth were free of occlusal caries than was the Midwest Caries I.D. LED-based device, although the Midwest Caries I.D. device more often revealed the presence of occlusal caries than did the DIAGNOdent pen.

Objectives:This study aimed to evaluate the extent of microleakage of a single type of composite resin (Clearfil Majesty Posterior, Kuraray, Osaka, Japan) following different preheating procedures in Class V cavities prepared with a diamond bur or Er:YAG (erbium: yttrium aluminum garnet) laser.Methods:The study randomly divided 72 permanent molar teeth divided into eight groups (n = 9): G1: Diamond bur–unheated composite resin (room temperature-24 ºC); G2: Diamond bur–composite preheated to 37 ºC; G3: Diamond bur–composite preheated to 54 ºC; G4: Diamond bur–composite preheated to 68 ºC; G5: Er:YAG laser–unheated composite resin (room temperature-24 ºC); G6: Er:YAG laser–composite preheated to 37 ºC; G7: Er:YAG laser–composite preheated to 54 ºC; and G8: Er:YAG laser–composite preheated to 68 ºC. The specimens were subjected to a thermal cycling regimen of 5000 cycles between 5 and 55 ºC; then they were immersed in a solution of 0.5% basic fuchsin dye for 24 hours. The dyed specimens were sectioned in the buccolingual direction and dye penetration was scored in a blinded manner using a five-point qualitative scale. Microleakage scores were analyzed with the Kruskall-Wallis, Mann-Whitney U, and Wilcoxon tests.Results:There were no statistically significant differences between the microleakages of composite applied to cavities prepared by either the Er:YAG laser or diamond bur (P>.05). Statistical analysis revealed significant differences between the enamel and dentin in all restorations (P<.001). However, there were no significant differences among the preheated groups (P>.05).Conclusions:For all groups, microleakage values were higher at gingival margins than at occlusal margins. The use of the Er:YAG laser at different preheating procedures did not influence the marginal sealing in Class V composite resin restorations.

This study evaluated the shear bond strength (SBS) of a traditional orthodontic bracket bonding agent (Transbond XT) against two self-etch, self-adhesive systems (Maxcem Elite and Vertise Flow). Sixty premolar teeth and sixty brackets were randomly and equally divided into five groups: Transbond XT (TXT) as the control, Maxcem Elite (ME) without etching, ME with etching (ME/ Etch), Vertise Flow (VF) without etching, and VF with etching (VF/Etch). Respective SBS results of the five groups were 9.86±3.20, 4.67±2.94, 7.82±2.56, 2.55±0.77, and 7.89±1.17 MPa. SBS values of the new self-etch adhesive systems were significantly lower than the traditional etch-and-rinse control (p<0.005). However, no significant differences were found between TXT and the self-adhesives applied with etching (p>0.005). After debonding, ARI scores "0" and "1" were predominant in non-etched ME and VF groups. It was concluded that new self-etch, self-adhesive bonding systems require additional phosphoric acid application to achieve comparable SBS values as the traditional orthodontic bonding agent.

Objective:To examine the amount of change in color and color parameters of a composite resin (Filtek P60) polymerized by five different polymerization methods.Methods: A Teflon mold (6mm in diameter, 2mm in height) was used to prepare the composite resin discs (n=10). G1: Polymerization with inlay oven; G2: Polymerization with HQTH and autoclave; G3: Polymerization with LED and autoclave; G4: Polymerization with HQTH; G5: Polymerization with LED. Colorimetric values of the specimens before and after polymerization were measured using a spectrophotometer. The CIE L*a*b color system was used for the determination of color difference. Analysis of variance (ANOVA) was used to analyze the data for significant differences. Tukey’s HSD test and paired two-tailed tests were used to perform multiple comparisons (α=.05).Results: There were no significant differences in total color change (ΔE*ab) among the polymerization groups (P>.05). However, the lowest color change (ΔE*ab) value was 3.3 in LED and autoclave; the highest color change (ΔE*ab) value was 4.6 in HQTH. For all groups, CIE L*, C*ab and a*values decreased after polymerization (P<.05). The highest Δb* and ΔC*ab values were observed in specimens polymerized in an inlay oven (P<.05).Conclusion: Composite resin material showed color changes above the clinically accepted value in all study groups (ΔE*ab≥3.3). All specimens became darker during investigation (ΔL*< 0). Specimens polymerized with inlay oven presented the highest Δb* values which means less yellow color in specimens. (Eur J Dent 2013;7:110-116)