Tensile bond strength of a so-called self-adhesive luting resin cement to dentin.

PURPOSE: The purpose of the study was to evaluate the bond strength and durability of a so-called self-adhesive resin luting cement to human dentin. In addition, the influence of a dentin adhesive system on the bond strength was tested. MATERIALS AND METHODS: Forty-eight dentin disks from human teeth were divided into two groups of 24 specimens.One group was bonded to composite resin tubes with the self-adhesive luting cement (RelyX Unicem Aplicap, 3MESPE), in the other group the dentin surfaces were conditioned with a three-step dentin adhesive system (OptiBondFL, Kerr) prior to bonding with the same cement. Three subgroups of eight specimens each were tested for tensile bond strength following storage in 37°C tap water for either 3 days or for 150 days with an additional 37,500 thermal cycles either between 20°C and 40°C ("soft TC") or between 5°C and 55°C ("hard TC"). Statistical analyses were performed with the Shapiro-Wilk test, Levene's test, two-way analysis of variance (ANOVA) followed by multiple comparisons with the Scheff test. RESULTS: Without the dentin adhesive, the mean tensile bond strengths after 3 days were 7.1 ± 3.8 MPa; after 150 days/"soft TC" 6.8 + 3.6; and after 150 days/"hard TC" 5.3 + 4.5 MPa. With the dentin adhesive, the mean bond strengths after 3 days were 16.5 ± 5.5 MPa; after 150 days/"soft TC" 13.1 + 3.9 MPa; and after 150 days/"hard TC" 10.1 + 5.2 MPa. CONCLUSION: Regardless of storage conditions, the use of a dentin adhesive increased the tensile bond strength of a self-adhesive resin luting cement significantly in comparison to the use of the luting cement without adhesive.

Does the Oral Health Impact Profile questionnaire measure dental appearance?

PURPOSE: The aim of this study was to evaluate whether there is a need to develop a new questionnaire measuring dental appearance or if this is already covered by the Oral Health Impact Profile (OHIP-49). MATERIALS AND METHODS: Based on internationally accepted guidelines about dental esthetics, a questionnaire was developed to measure dental appearance (QDA). Eleven items defined a QDA sum score (0 = absolutely satisfied, 44 = absolutely dissatisfied). Furthermore, oral health-related quality of life was evaluated using the German version of the OHIP-49 and the OHIP-esthetic. Thirty patients (14 women, 16 men; mean age 59 +/- 10 years) were included in the study. All patients received a complete oral rehabilitation including the anterior teeth of the maxilla. Questionnaires were completed before and after treatment. RESULTS: The median values were 16 and 1.5 for the QDA sum score, 46 and 16 for the OHIP sum score, and 14.5 and 2 for the OHIP-esthetic before and after rehabilitation, respectively. The improvement after treatment was significant for all questionnaires (P < or = .0001). Between the QDA sum score and the OHIP sum score or any of the OHIP subscales (the only exception being "psychological discomfort"), no significant correlation could be found (P > .05). Between the QDA sum score and the OHIP-esthetic, a significant correlation could be found before treatment (r = 0.505, P = .004) but not after treatment (P > .05). CONCLUSIONS: If the OHIP-49 is used in clinical studies and a profound evaluation of dental appearance is desired, it is reasonable to use an additional esthetic modulus.

The central single implant in the edentulous mandible: improvement of function and quality of life. A report of 2 cases.

Implant-retained overdentures are a reliable treatment option for edentulous patients, especially when only few implants can be placed. Internationally, 2 implants are considered adequate to retain an overdenture in the edentulous mandible. However, for many patients, 2 implants can be cost-prohibitive. By means of 2 clinical cases, it is shown that the insertion of a single implant in the middle of the mandible might stabilize the prosthesis and improve the oral health quality of life and the chewing function. A ball attachment with a screw-activated matrix was used to retain the overdenture. Early clinical results are promising. However, before this method can be recommended for general clinical application, long- term clinical results are needed.

Assessment of dental appearance following changes in incisor angulation.

PURPOSE: This study evaluated the assessment of attractiveness of standardized changes in incisor angulation of different tooth arrangements. MATERIALS AND METHODS: Four sets of images showing the maxillary anterior teeth without lips against a black background were used for evaluation. Each set contained the original photograph, one computer-manipulated symmetric image, and four images with different standardized changes in incisor angulation (10 degrees). The judges, consisting of three groups (30 dental students, 30 medical students, 30 art students), ranked each photo set for attractiveness from 1 (most attractive) to 6 (most unattractive). RESULTS: The mean ranking (in parentheses) showed that symmetric teeth with ideal axes (2.5) and changes in the angulation of one (2.8) or both (2.5) lateral incisors were significantly more attractive than the angulation of one (4.2) or both (4.6) central incisors. There were no differences between the groups of participants. All findings were reproducible. CONCLUSION: Tooth arrangements showing central incisors with ideal axes were more attractive. Slight changes in the angulation of one or both lateral incisors did not influence attractiveness negatively.