PubMed · 3554420
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
M François. 1986. [The glued prosthesis].. https://pubmed.ncbi.nlm.nih.gov/3554420/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Atomic force microscopy (AFM) has been used to determine microstructural changes, etching rates of peritubular dentin, and intertubular dentin recession during demineralization in dilute acidic solutions. These studies have not included many forms of altered dentin, including noncarious sclerotic root dentin associated with Cl V (abfraction) lesions. We sought to determine microstructural changes and recession rates during demineralization in citric acid (pH 2.5, 0.018M) for the transparent/sclerotic zone. Highly polished dentin disks were prepared from teeth with noncarious C1 V lesions (n = 3) and compared with normal root dentin (n = 3). Samples were etched at 5-s intervals for 1 min and at longer intervals up to 30 min. The depth changes in various portions of the dentin with respect to the reference layer were measured and changes in microstructure observed in solution in the wet cell of the AFM. In sclerotic dentin, most tubule lumens were occluded with crystalline deposits that etched more slowly than the other dentin components, but etching rates could not be determined due to their irregular geometry. The intertubular dentin recession quickly reached a plateau after a depth change of <1 microm for all dentin types, in agreement with prior work. Mixed linear regression models indicated an important difference between the etching of sclerotic intertubular dentin and that of non-sclerotic root dentin that became apparent after 600 s (p = 0.037). The sclerotic intertubular dentin underwent less depth change at the plateau (558 nm) compared to normal root dentin (744 nm). In addition, normal root dentin underwent significantly greater recession than coronal dentin (p = 0.002). The results of this study indicate that intertubular sclerotic dentin from Cl V lesions etches differently than normal root dentin, and this may help explain the difficulties in restoring such lesions with current bonding procedures.
STATEMENT OF PROBLEM: Previous studies have shown that provisional cement cannot be completely removed from the dentin surface and the remnants inhibit adhesion of resin cement to dentin. PURPOSE: This study investigated the effects of dentin conditioners on resin-dentin bonding after provisional cement contamination. MATERIAL AND METHODS: A total of 216 bovine dentin specimens were divided into 2 groups with and without provisional cement coating on the dentin surface. Each group was further divided into 3 subgroups with 2 conditioning methods and without dentin conditioning (36 specimens per subgroup). The 2 methods applied were (1) phosphoric acid etching and (2) phosphoric acid etching, followed by sodium hypochlorite gel. Provisional cement was completely removed with a curette before dentin conditioning. Stainless steel rods were luted to dentin surfaces with Panavia 21 resin cement. Tensile bond strengths were measured before and after thermocycling. The dentin surface was analyzed by SEM and energy dispersive x-ray spectroscopy. Three-way ANOVA and Scheffe's comparison test were performed (P =. 05). RESULTS: Bond strength was significantly influenced by provisional cement application, type of dentin conditioning, and thermocycling. Bond strength decreased when treated with provisional cement, but the decreased strengths were restored to their original values or higher by both dentin conditioners used. Specimens treated with sodium hypochlorite gel applied after phosphoric acid etching demonstrated the highest bond strengths with good stability after thermocycling. CONCLUSION: Application of sodium hypochlorite gel after phosphoric acid etching was more effective than etching with phosphoric acid alone to eliminate the inhibitory effect of provisional cement remnants on adhesion between resin cement and dentin.
OBJECTIVES: This study was carried out to combine flexural properties of FRC materials with aesthetic values of ceramics. METHODS: The bonding strength of fibre-reinforced composite to ceramic was determined. Afterwards, 8 three unit and 8 four unit FPDs (fixed partial dentures) were manufactured based on the experimental design and were then adhesively luted onto human molars. After thermal cycling and mechanical loading in an artificial environment, the fracture strength and marginal adaptation was determined. FPDs made of FRC (fibre-reinforced composite) materials were used as a control. RESULTS: The most reliable bonding strength of ceramic to FRC material was achieved using acid etching in combination with adhesive luting techniques. Median fracture strength values of 575 N for three unit FPD and 876 N for four unit FPD were established. More than 85% of the experimental FPDs showed a perfect margin while less than 15% revealed a marginal gap, even after thermal cycling and mechanical loading (TCML). The strongest influence of TCML on the marginal adaptation of the experimental design FPD was determined within the four unit system showing approximately a 10% change in marginal gap and perfect margin. SIGNIFICANCE: Assuming an improvement in adhesive bonding between the ceramic and the FRC material and, in addition, an enhancement of the contact surface between pontic and abutment, the hybrid technique could represent an interesting procedure for further investigations and, eventually, clinical implication.