PubMed · 8762800
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
S R Todd. 1996-06-08. Post dentine bonding sensitivity.. https://doi.org/10.1038/sj.bdj.4809104
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
STATEMENT OF PROBLEM: There are no long-term data on Dicor glass-ceramic restoration survival in the human oral cavity and the effect that different technical and clinical variables have on survival. PURPOSE: This prospective study examined the relationship of different clinical parameters on the survival of Dicor glass-ceramic restorations in the human oral cavity. MATERIAL AND METHODS: A total of 417 subjects (from 17 to 91 years of age) participated. All subjects required single unit fixed prosthodontics in any area of the mouth and/or 3-unit fixed partial dentures or cantilevered anterior restorations. They were offered the option of a gold or conventional metal-ceramic restoration, or a Dicor restoration with potentially improved esthetic results, better wear characteristics, and diminished oral plaque accumulation. Overall survival of the restorations was determined and the effect of various clinical parameters evaluated with Kaplan-Meier survival curves. Log rank tests were used to determine statistically significant differences among parameters. RESULTS: For the 1444 units placed, 188 failures were recorded. Total time at risk for the units was 7319 years providing an estimated risk of 2.45% per year. Probabilities of survival of "typical" acid-etched Dicor and nonacid-etched Dicor restorations were 76% and 50%, respectively, at 14.1 years (P <.001). Probabilities of survival of typical acid-etched and nonacid-etched Dicor complete coverage restorations were virtually identical to those observed in the full data set. There was a 2.2 times greater risk of failure associated with the use of nonacid-etched Dicor complete coverage than acid-etched restorations (P <.01). Complete coverage restoration survival was highest in the incisor region and decreased to the molars in both arches. Second molars showed the highest failure rate. No complete coverage restorations failed on lateral incisors during the entire study. Probability of survival of a typical acid-etched Dicor complete coverage restoration in male subjects was 71%, and 75% for female subjects at 14.1 years (P <.01). The major difference appeared to be due to a greater failure rate in the maxillary arch of the male. Survivor functions of acid-etched Dicor complete coverage restorations for subjects in <33 years, 33 to 52 years, and 52 years age groups were 88% at 9 years, 62% at 14 years, and 82% at 14 years, respectively. CONCLUSIONS: Dicor restorations can survive successfully over time with certain reservations. Long-term survival improved significantly when restorations were acid-etched before luting. Complete coverage restoration failures per year decreased from molars to incisors in both arches, suggesting that complete coverage restorations on molars represented a serious risk. No Dicor complete coverage restoration on lateral incisors failed during the study. Restorations failed less often in female than male subjects.
This article describes the use of a resin-bonded retainer in combination with an acrylic resin stent to stabilize a free gingival graft. This retainer also prevents migration of muscle attachment after surgery to deepen a section of the vestibule where the oral mucosa closely approached the gingival margin. The acrylic resin stent is attached to the resin-bonded retainer by means of an integrally cast metal framework. After surgery, the retainer is attached to the occlusal two thirds of the buccal surfaces of maxillary molar teeth by using the acid-etched resin bonding technique. The stent effectively retains the graft, is simple to fit, and does not cause any permanent damage to the enamel. It has none of the disadvantages of conventional removable acrylic resin stents.
STATEMENT OF PROBLEM: One of the most critical steps of the porcelain restoration technique is cementation. Mechanical stress before the resin cement reaches a certain degree of polymerization can displace or even fracture the restoration. Dual-cure materials are intended to be more effective at early stages of polymerization because they contain both photoinitiator and components for chemically activated reaction. PURPOSE: This study evaluated the early shear strength of bonding between porcelain and dentin, using dual-cure cements. MATERIAL AND METHODS: Sixty nonrestored human molars and premolars were randomly divided in 12 groups. The dual-cure cements tested were Porcelite and Dual. A chemically activated cement was also tested (C&B luting composite). Ceramic pieces, 3 mm high, were etched with hydrofluoric acid, silane-coated, and then bonded to flat dentin surfaces with each of the cements, associated with Optibond adhesive system. Photoactivation was made by using a light unit with 450 mW/cm2. The specimens were stored in water at 37 degrees C. Testing times were 10, 30, 90 minutes, and 7 days (referred to as maximum strength). RESULTS: Both Porcelite and Dual dual-cure cements show statistically similar shear strength for the same time interval. The chemically activated material showed statistically lower values when compared with both dual-cure cements, regardless of the time interval. Results at 7 days were much higher than those obtained at 90 minutes for the 3 cements tested. CONCLUSIONS: Both dual-cure cements tested presented similar results. The bond strength of dual-cure cements to dentin was higher at all time intervals than that obtained for chemically activated material. The high values for the coefficient of variation confirmed the technique-sensitive nature of the porcelain/dentin bonding procedure. Although dual-cure cements reach higher bonding strength values faster than the chemically activated material, it is not recommended to stress the bonding until 90 minutes after cementation, because the strength at that time is much lower than the maximum.