Bond Strengths of Universal Adhesives to Dentin Contaminated with a Hemostatic Agent.

PURPOSE: To evaluate the microtensile bond strength (µTBS) of three universal adhesives to dentin contaminated with a hemostatic agent. MATERIALS AND METHODS: Ninety-six human premolars were cut to expose mid-coronal dentin. The teeth were randomly divided into a control group (uncontaminated dentin) and an experimental group in which a hemostatic agent was applied (contaminated dentin). Each group was further divided into 6 subgroups according to universal adhesives - SBU (Single Bond Universal), OPU (OptiBond Universal), CBQ (Clearfil Universal Bond Quick) - and etching mode, either etch-and-rinse (ER) or self-etch (SE). Following adhesive application, composite was placed in two increments and light cured. The specimens were stored in distilled water at 37°C for 24 h. The µTBS test was performed using a universal testing machine. Failure mode was assessed using a light microscope. The data were statistically analyzed using three-way ANOVA followed by Scheffe's test (p < 0.05). The resin-dentin interface was observed using scanning electron microscopy. RESULTS: Significantly lower bond strength was observed when the universal adhesives were bonded to contaminated dentin in SE mode (p < 0.05). In contrast, the µTBS of the universal adhesives in ER mode was not affected by contamination (p > 0.05). The µTBS of CBQ to contaminated dentin was significantly lower than that of the other adhesives. Observation of the resin-dentin interface revealed limited resin penetration when the universal adhesive was applied in SE mode on contaminated dentin. CONCLUSION: Contaminating the dentin with a hemostatic agent significantly reduced the µTBS of the universal adhesives in SE mode. However, this adverse effect was not found when the universal adhesives were used in ER mode.

Not chewing food among the Thai elderly with complete denture.

OBJECTIVE: The study aims to investigate the use of a complete denture in terms of not chewing food and determining the strength of association between not chewing food and several potential risk factors among the Thai elderly. MATERIAL AND METHOD: Under the support of the "Khao Aroi" or "Delicious Rice" or "Dental Implant" Project of Institute of Dentistry, Department of Medical Services, Ministry of Public Health, and in co-operation with the Ministry of Science and Technology during 2007-2011, a cross-sectional survey by multi-stage cluster sampling was conducted in 2008, in 21 provinces, 87 hospitals, with 2,676 Thai elderly. The sample was drawn from a sampling frame of 58,043 target Thai people aged 60 years and over under the Dental Prosthesis Service Campaign (DPSC) project during 2005 and 2007. All Thai elderly, who received a complete denture from the DPSC project at least three months prior were surveyed from May to October 2008 through questionnaires. Data were analyzed by a set of descriptive analyses and binary logistic regression models. RESULTS: Not chewing food among the Thai elderly, after receiving a complete denture, was 12.5%, quite a bit more effective than ordinary work. Nontaluck found 38% for the proportion not wearing dentures in the 30-baht health care program. This finding is confirmed by the work of Dalodom et al that the use of dentures by Thai elderly was 93% in the DPSC project. The important risk factors that influenced not to chew food were satisfaction with dentures, patients satisfaction with the denture fitting and care, while controlling the amount of dentures, respectively. CONCLUSION: Satisfaction of patients with their dentures, good oral health care in fitting denture work, and good communication between dentists and patients are important keys affecting the use of dentures.