Effect of liners and primers on tensile bond strength between zirconia and resin-based luting agent

PURPOSE: The effect of silica-based glass-ceramic liners on the tensile bond strength between zirconia and resin-based luting agent was evaluated and compared with the effect of 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing primers. MATERIALS AND METHODS: Titanium abutments and zirconia crowns (n = 60) were fabricated, and the adhesive surfaces of the specimens were treated by airborne-particle abrasion. The specimens were divided into 5 groups based on surface treatment: a control group, 2 primer groups (MP: Monobond Plus; ZP: Z Prime Plus), and 2 liner groups (PL: P-containing Liner; PFL: P-free Liner). All specimens were cemented with self-adhesive resin-based luting agent. After 24-hour water storage and thermocycling (5,000 cycles, 5℃/55℃), the tensile bond strength was measured using a universal testing machine. Failure mode analysis and elemental analysis on the bonding interface were performed. The data were analyzed using Kruskal-Wallis test, Dunn's post hoc test, and Fisher's exact test. RESULTS: The liner groups and primer groups showed significantly higher tensile bond strengths than that of the control group (P < .05). PFL showed a significantly higher tensile bond strength than the primer groups (P < .05). The percentage of mixed failure was higher in the primer groups than in the control group (P < .001), and all the specimens showed mixed failure in the liner groups (P < .001). A chemical reaction area was observed at the bonding interface between zirconia and liner. CONCLUSION: The application of liner significantly increased the tensile bond strength between zirconia and resin-based luting agent. PFL was more effective than MDP-containing primers in improving the tensile bond strength with the resin-based luting agent.

Considerations in the selection of method for clinical crown lengthening / 대한치과보철학회지

Clinical crown lengthening procedure would be an effective method for overcoming adverse clinical condition such as short abutment length. There are three kinds of methods in clinical crown lengthening, those are, surgical crown lengthening, orthodontic extrusion and surgical extrusion. Clinicians have to try their best to choose a proper method among those for favorable results. This report aims to review the considerations in each method with various cases and to suggest a decision flow for appropriate selection.

Literature review and case report of prosthetic rehabilitation with telescopic denture / 대한치과보철학회지

Telescopic denture has advantages such as transfer the occlusal force to the long axis of the abutment, easiness of oral hygiene management, increase of retention and stability, splint effect due to secondary fixation between abutments and have been reported a higher success rates than conventional removable partial denture (RPD). However, there are disadvantages such as complex laboratory procedures, long treatment periods and high costs, and high incidence of complications. This clinical report describes two cases, a 4-point supported telescopic denture using telescopic crown and a 2-point supported telescopic denture using conical crown with functionally satisfactory results. Frequent complications of telescopic denture, which are reported in various literature were reviewed. Clinical and laboratory procedures were performed in consideration of complications that reported.

Tooth preparation design of dental laminate veneer: a review article

Tooth preparation design is essential for successful laminate veneer treatment. Preservative tooth preparation limited on enamel, supra-margin advantageous for plaque control, and maintaining contact points known as a standard concept. However, the tooth preparation design has been the controversial issue. In biomechanical considerations, the incisal coverage should be decided on esthetic needs and necessity for the anterior guidance reconstruction. In occasion for sufficient enamel thickness, preparation can prolong to the palatal side but not recommended at palatal concavity. Elongation to contact point is selective option according to the cases. If an old resin restoration located at contact area, laminate veneer should cover over half area of that after surface treatment. The laminate veneer can be also selected at a partially discolored tooth root canal therapy (RCT) and at this occasion, the fiber-reinforced composite (FRC) posts are recommended.