Journal of Dental Medicine

Background and Aims: The bond strength between veneer ceramics and zirconia frameworks is the weakest component in the layered ceramics. Due to the possible effect of adding pigments to the core materials on the bond strength between core and veneer as well as the introduction of new ceramic materials in dentistry, the aim of this study was to compare the zirconia core-veneer microtensile bond strength using two ceramic veneers with or without coloring the core.
Materials and Methods: In this experimental study, 12 disc-shaped specimens were fabricated using a manually aided design- manually aided manufactured (MAD/MAM) zirconia core (Zirkonzahn). Two veneering ceramics of Ceram Kiss and Zirkonzahn ICE were also used to veneer the specimens. Half of the Zirkonzahn discs were remained white and the others were colored by shade A2.Then, the discs were cut into microbars (30 for each group) and the microtensile bond strength of the core-veneer was calculated. The specimens were assessed using scanning electron microscopy (SEM) and the data were analyzed using two-way ANOVA and Student's t-test.
Results: Significant differences with respect to veneer layer were found (P<0.001). No significant differences were seen among colored and uncolored cores (P=0.69).
Conclusion: According to the apparent effect of veneering ceramics on the core-veneer bond strength, careful selection of these agents is essential to achieve adequate bond strength between core and veneer to prevent delaminating and chipping failures of zirconia veneered restorations.

Background and Aims: The oral impact on daily performance (OIDP) is one of the oral health-related quality of life indices to measure physical, social and mental consequences of the oral health status. This study aimed to evaluate the OIDP index in patients referring to Tehran dental school.

Materials and Methods: Four hundred and ninety nine patients referring to patients' clinic in Dental School of Tehran University of Medical Sciences in spring 2011 participated in this study. They were interviewed for demographic factors including age, gender and level of education, and OIDP index questionnaire before receiving any treatment. Statistical analysis was carried out by means of linear regression modeling.

Results: 85.6% of patients confirmed that they had at least one oral impact on daily performance during the last 6 months. The most prevalent performances affected were eating (50.1%) and smiling and showing teeth without shame (12.8%). The mean OIDP score for the population was 5.6 ranging from 0 to 36. Linear regression modeling controlling for age, gender and years of education revealed that older patients and those with lower education had significantly higher OIDP scores.

Conclusion: The effect of oral health on daily performance was clear. The association among age, education and oral impact on daily performance indicates the need for more comprehensive preventive oral health care for adults with lower educational level.

  Background and Aims: Hepatitis B is an important infection route in dentistry requiring different disinfectants to prevent its transmission. The aim of this study was to compare the effects of chemical disinfectants (FD366, ISORAPID and 5% sodium hypochlorite 2/100) to remove Hepatitis B infections from the dental surfaces.

  Materials and Methods: In this experimental laboratory trial, serum of 10 HBV patients was poured into microtubes, FD366, ISORAPID and hypochlorite disinfectants were added to them. PCR experiments with viral diagnostic kits were used to diagnose the virus genome. Real time PCR was used to evaluate after incubation with the disinfectants. The reductions occurred in the viral load of Hepatitis B were statistically analyzed using Kruskal-wallis and Mann-Whitney U tests .

  Results: No significant antiviral efficacy was noted following the application of FD366 and ISORAPID disinfectants (P=0/07). However, hypochlorite showed the most efficacy to disinfect Hepatitis B and a significant difference was found among them (P<0.0001).

  Conclusion: Under the study limitations, FD366 and ISORAPID disinfectants did not show adequate efficacy to remove Hepatitis B virus. Hypochlorite was the most effective disinfectant.