Objective:To analyze the accuracy of the digital imaging fiber optic transillumination (DIFOTI) on diagnosis of caries lesions depth using DIAGNOcam system.Methods:This experiment adopted self-matching design.Seventy-four extracted teeth (molar:sixty-six,premolar:eight) with one caries lesions in proximity which were not damaged in surface marginal ridge were selected.Dental calculus and dental stains were removed from the extracted teeth for standby application.A sign was marked in the middle of the occlusal surface edge at the side of decay.Then the teeth were fixed in the standard model of dentition and cavities were adjacent with the sound tooth surface.Sticky wax was applied to seal the level of 2 mm beyond cemento-enamel junction (CEJ) in the direction of occlusion and interproximal space to imitate gingival margin and gingival papilla.The standard models of dentition was seated in imitation head mold.The lesions depth degree was looked into and checked with DIAGNOcam system.Besides,the pictures on the occlusal surfaces were recorded and saved.The sign above could be seen on the picture.The measuring tool in DIAGNOcam system was used to measure the depth of the caries from the sign (as starting point) to the deepest point of caries in the pictures and its length was recorded for a.The line a was lengthened to the contralateral edge of occlusal surface in the photo and the length was recorded for b.A line from the marked point on the occlusal surface edge of the extracted teeth was draw parallel to the line b on the corresponding photo and its length was recorded for c.The depth of the cavities on the projected images was recorded for d,and calculated d/a =c/b (digital optical fiber measured decay depth/caries damage depth of the image =actual tooth width/tooth width of the image),and d =c/b × a inferred.At last,the teeth were taken out from the standard model dentition.The decay of the tooth was removed completely.The actual depth of the cavity was recorded for D.The difference between d and D was recorded for Δd.The software of SPSS 20.0 was used to test the consistency of the results,and the MedCalc 14.8.1.0 software was used for Bland-Altman analysis.Results:The intraclass correlation coefficient (ICC) between d and D was 0.951 (ICC ＞ 75 ％),P =0.263.There was a function relationship y =0.23 ± 0.9 1x between d (x) and D (y).Bland-Altman analysis method showed that the mean of Δd (Δd) was 0.05 mm,the standard deviation of Δd (ΔdsD) =0.308,and the 95％ confidence interval was (-0.55 to 0.65).The amplitude of difference was clinically acceptable.So the consistency of the two measurement modes was high.Conclusion:There was no significant difference between the depth of caries lesions checked with DIAGNOcam system and the depth of the actual cavity,and the consistency was very good.The vitro study suggests that the DIAGNOcam system may be used to assess the depth of caries cavity as a useful tool in diagnosis and treatment.

OBJECTIVETo evaluate the adhesive interface and micro-tensile bond strength (μTBS) of infiltrating resin directly bonded to normal dentin.

METHODSTwenty extracted human molars were collected and ground to expose fresh dentin surface. An infiltrating resin (ICON, DMG, Germany) was served as experimental group and Clearfil SE Bond adhesive (Kuraray, Japan) as control group. Following the application of primer (Kuraray, Japan), the specimens were applied infiltrating resin or adhesive respectively and blocks of composite resin were built up. The adhesive interfaces were observed using scanning electron microscope (SEM) and the μTBS was measured by micro-tensile test before and after thermal cycling.

RESULTSThe infiltrating resin could penetrate into micro-structure of dentin created by SE Bond primer. A layer of about 180 μm-long and dense resin tags was observed under SEM in infiltrating resin group. The μTBSs were (35 ± 10) MPa before and (35 ± 9) MPa after thermal cycling respectively in infiltrating resin group, and the difference was not statistically significant (P>0.05). The μTBSs were (38±8) MPa before and (24±7) MPa after thermal cycling respectively in control group, and the difference was statistically significant (P<0.05). After thermal cycling, the μTBS of infiltrating resin group was significant higher than that of control group.

CONCLUSIONSThe infiltrating resin could penetrate into the micro-structure of dentin created by SE Bond primer. The bond strength and the bonding durability of infiltrating resin were similar to that of SE Bond adhesive.

Adhesives ; chemistry ; Composite Resins ; chemistry ; Dental Bonding ; Dentin ; Dentin-Bonding Agents ; chemistry ; Humans ; In Vitro Techniques ; Japan ; Materials Testing ; Microscopy, Electron, Scanning ; Molar ; Resin Cements ; chemistry ; Surface Properties ; Tensile Strength