This study analyzed the influence of dental adhesive/primer on the bond strength between indirect resin composite and the resin cement.

Seventy disc specimens of indirect resin composite (Tescera Dentin, Bisco) were fabricated. And bonding area of all specimens were sandblasted and silane treated for one minute. The resin cements were used with or without application of adhesive/primer to bonding area of indirect resin restoration: Variolink-II (Ivoclar-Vivadent): Exite DSC, Panavia-F (Kuraray): ED-Primer, RelyX Unicem (3M ESPE): Single-Bond, Duolink (Bisco): One-step, Mulitlink (Ivoclar-Vivadent): Multilinh Primer.

Shear bond strength was measured by Instron universal testing machine.

Adhesive application improved shear bond strength (p < 0.05). But Variolink II and Panavia-F showed no statistically significant difference according to the adhesive application.

With the above results, when resin inlay is luted by resin cement it seems that application of dental adhesive/primer is necessary in order to improve the bond strength.

The purpose of this study was to compare the microtensile bond strength in Class I cavities associated with different light curing modes of same light energy density.

Occlusal enamel was removed to expose a flat dentin surface and twenty box-shaped Class I cavities were prepared in dentin. Single Bond (3M Dental product) was applied and Z 250 was inserted using bulk technique. The composite was light-cured using one of four techniques; pulse delay (PD group), soft-start (SS group), pulse cure (PC group) and standard continuous cure (CC group). The light-curing unit capable of adjusting time and intensity (VIP, Bisco Dental product) was selected and the light energy density for all curing modes was fixed at 16 J/cm². After storage for 24 hours, specimens were sectioned into beams with a rectangular cross-sectional area of approximately 1 mm². Microtensile bond strength (µTBS) test was performed using a universal testing machine (EZ Test, Shimadzu Co.). The results were analyzed using oneway ANOVA and Tukey's test at significance level 0.05. The µTBS of PD group and SS group was higher than that of PC group and CC group.

Within the limitations of this in vitro study, modification of curing modes such as pulse delay and soft start polymerization can improve resin/dentin bond strength in Class I cavities by controlling polymerization velocity of composite resin.

Type II root canal was defined that two canals leave the chamber and merge to form a single canal at short of the apex. The aim of this study was to analyse the master apical file (MAF) size according to various instrumentation techniques in the type II root canal when each canal was enlarged to working length.

Eighty mesial roots of molar with ISO #15 initial apical file (IAF) size in type II root canals were randomly divided into four experimental groups with 20 teeth each. According to enlarging instruments, four groups are: K-FLEXOFILE® (KF), engine-driven Ni-Ti PROTAPER® (PT), HERO Shaper® (HS), K³ ™ (K3). All canals were enlarged to each working length with ISO #30 size: #30 in KF, F3 in PT, .04/30 in HS, and .06/30 in K3. The master apical file (MAF) size was confirmed by tactile sensation and universal testing machine (EZ test, Shimadzu Co., Kyoto, Japan). The mean MAF size was statistically compared using one-way ANOVA and Tukey HSD test at the 0.05 probability level.

These results show that the MAF size was appeared one or two sizes larger than the final enlarging instrument when all canal in type II configuration were enlarged to each working length. Therefore, the clinician have to confirm the apical stop once more after instrumentation of type II root canal.

The purpose of this study was to evaluate the effect of additional etching procedure prior to Maxcem resin cement application in indirect restoration cementation using push-out bonding strength.

One hundred and two extracted human molars were used to make indirect resin restorations of gold inlay and Synfony. These restorations were cemented using Maxcem and Variolink II. Additional etching procedures were done for one group with Maxcem. Three groups have 17 specimens in both restoration types. Push-out bond strength was measured using multi-purpose tester and calculated for bonding strength per sqaure-millimeter area. The mean bonding strength values were compared using SPSS 12.0K program for one-way ANOVA and Scheffe's Test with 95% significance.

Under the condition of this study, the additional etching procedure prior to usage of Maxcem resulted in reduced bond strength for both of restoration types.

Herpes zoster, an acute viral infection produced by the varicella zoster virus, may affect any of the trigeminal branches. This case report presents a patient with symptoms mimicking odontogenic pain. No obvious cause of the symptoms could be found based on clinical and radiographic examinations. After a dermatologist made a diagnosis of herpes zoster involving the third trigeminal branch, the patient was given antiviral therapy. Two months later, the facial lesions and pain had almost disappeared, and residual pigmented scars were present. During the diagnostic process, clinicians should keep in mind the possibility that orofacial pain might be related to herpes zoster.

"Residual stress" can be developed during polymerization of the dental composite and it can be remained after this process was completed. The total amount of the force which applied to the composite restoration can be calculated by the sum of external and internal force. For the complete understanding of the restoration failure behavior, these two factors should be considered. In this experiment, I compared the residual stress of the recently developed nanofilled dental composite by ring slitting methods.

The composites used in this study can be categorized in two groups, one is microhybrid type-Z250, as control group, and nanofilled type-Grandio, Filtek Supreme, Ceram-X, as experimental ones. Composite ring was made and marked two reference points on the surface. Then measure the change of the distance between these two points before and after ring slitting. From the distance change, average circumferential residual stress (σθ) was calculated. In 10 minutes and 1 hour measurement groups, Filtek Supreme showed higher residual stress than Z250 and Ceram-X. In 24 hour group, Filtek showed higher stress than the other groups.

Following the result of this experiment, nanofilled composite showed similar or higher residual stress than Z250, and when comparing the Z250 and Filtek Supreme, which have quite similar matrix components, Filtek Supreme groups showed higher residual stress.

This study investigated the clinical effectiveness and safety of sealed bleaching compared to conventional in-office bleaching using a randomized clinical trial of split arch design. Ten participants received a chairside bleaching treatment on the upper anterior teeth, and each side was randomly designated as sealed or control side. A mixture of Brite powder (PacDent, Walnut, USA), 3% hydrogen peroxide and carbamide peroxide (KoolWhite, PacDent, Walnut, USA) were used as bleaching agent. The control side was unwrapped and the experimental side was covered with a linear low density polyethylene (LLDPE) wrap for sealed bleaching. The bleaching gel was light activated for 1 hour. The tooth shades were evaluated before treatment, after treatment, and at one week check up by means of a visual shade (VS) assessment using a value oriented shade guide and a computer assisted shade assessment using a spectrophotometer (SP). The data were analyzed by paired t-test.

In the control and sealed groups, the visual shade scores after bleaching treatment and at check up showed statistically significant difference from the preoperative shade scores (p < .05). The shade scores of the sealed group were significantly lighter than the control immediately after bleaching and at the check-up appointment (p < 0.05). Compared to prebleaching status, the ΔE values at post-bleaching condition were 4.35 ± 1.38 and 5.08 ± 1.34 for the control and sealed groups, respectively. The ΔE values at check up were 3.73 ± 1.95 and 4.38 ± 2.08 for the control and sealed groups. ΔE values were greater for the sealed group both after bleaching (p < .05) and at check up (p < .05).

In conclusion, both ΔE and shade score changes were greater for the sealed bleaching group than the conventional bleaching group, effectively demonstrating the improvement of effectiveness through sealing.

This study was conducted to evaluate the influence of the C-factor on the bond strength of a 6th generation self-etching system by measuring the microtensile bond strength of four types of restorations classified by different C-factors with an identical depth of dentin.

Eighty human molars were divided into four experimental groups, each of which had a C-factor of 0.25, 2, 3 or 4. Each group was then further divided into four subgroups based on the adhesive and composite resin used. The adhesives used for this study were AQ Bond Plus (Sun Medical, Japan) and Xeno III (DENTSPLY, Germany). And composite resins used were Fantasista (Sun Medical, Japan) and Ceram-X mono (DENTSPLY, Germany).

The results were then analyzed using one-way ANOVA, a Tukey's test, and a Pearson's correlation test and were as follows.

There was no significant difference among C-factor groups with the exception of groups of Xeno III and Ceram-X mono (p < 0.05).

It was concluded that the C-factor of cavities does not have a significant effect on the microtensile bond strength of the restorations when cavities of the same depth of dentin are restored using composite resin in conjunction with the 6th generation self-etching system.

The purpose of this study is to observe and compare the remineralization tendencies of artificially demineralized enamel by remineralization solutions of different degree of saturations at pH 5.5, using a polarizing microscope and computer programs (Photoshop, Image pro plus, Scion Image, Excel).

For this study, 36 sound permanent teeth with no signs of demineralization, cracks, or dental restorations were used. The specimens were immersed in lactic acid demineralization solution for 3 days in order to produce dental caries artificially that consist of surface and subsurface lesions. Each of 9 or 10 specimens was immersed in pH 5.5 lactic acid buffered remineralization solution of three different degrees of saturation (0.25, 0.30, 0.35) for 12 days. After the demineralization and remineralization, images were taken by a polarizing microscope (× 100). The results were obtained by observing images of the specimens, and using computer programs, the density of caries lesions were determined.

In conclusion, in the group with the lowest degree of saturation, remineralization occurred thoroughly from the surface to the subsurface lesion, whereas in the groups with greater degree of saturation showed no significant change in the subsurface lesion, although there was corresponding increase in the remineralization width on the surface zones.