Clinical longevity of resin-bonded bridges bonded using a vinyl-thiol primer

Longevity of resin-bonded fixed partial dental prostheses made with metal alloys

Objectives

The purpose of this study was to evaluate the clinical performance of resin-bonded fixed partial dental prostheses (RBFPDPs) made with metal alloys.

Materials and methods

The retention of 311 RBFPDPs from 226 patients fabricated from 1983 to 2013 using an adhesive resin was clinically evaluated. Partial or complete debonding of the RBFPDP or framework fracture was considered a treatment failure. All data were obtained from clinical examinations, and missing data were censored at the date of the last available information. The effect of the following factors on survival rate were investigated: patient gender, location (maxilla/mandible and anterior/posterior), number of missing teeth, number of abutment teeth, framework structure, type of metal alloy, patient age at the point of cementation, cement type, and distinction of the treating dentist. Data were analyzed with the Kaplan–Meier survival tests, log-rank tests, and Cox regression analyses (α = 0.05).

Results

The Kaplan–Meier survival rate was 41.2 % ± 6.5 % (standard error) at 28.8 years (last outcome event). Significant differences were found for patient age and treating dentist (p < 0.05). The risk of failure in younger patients was 1.7 times greater than that in older patients and that of inexperienced dentists was 2.0 times greater than that of dentist experienced and specialized in adhesive dentistry.

Conclusions

When fabricating RBFPDPs for younger patients, mechanical preparation for bonding may be necessary in consideration of the risk for debonding. Experienced dentists may achieve better results.

Clinical relevance

Mastery of skills is necessary to ensure excellent prognoses for RBFPDPs.

Considerations for single tooth replacement in an esthetic zone-review of conservative treatment options

BACKGROUND

This literature review aimed to identify and assess the conservative treatment options for replacing a single missing anterior tooth, for patients who cannot afford implants or traditional bridges.

MATERIALS AND METHODS

The evidence was obtained using MEDLINE searches. A total of 19 studies met the inclusion criteria. None of these studies scored higher than 10 of 17, suggesting that all studies did not have strong evidence. Three of the studies examined resin-bonded bridges (RBBs), whereas the other three investigated removable partial dentures (RPDs). None of the studies had random patient selection. Three of these studies had controlled allocation of patients. The other three allowed new patients to enter the study throughout the study period. Placement of the prosthesis was only conducted in one study, whereas the rest of the studies examined patients with preexisting prostheses.

RESULTS AND CONCLUSION

In general, all 19 studies were weak due to poor study design, no acceptable controls, no direct comparison between RBBs and RPDs, lack of longitudinal studies and no differentiation between the anterior and posterior prostheses. Therefore, no definitive treatment conclusion can be made until studies of stronger design are conducted.

A study of self-adhesive resin cements for bonding to silver-palladium-copper-gold alloy -- effect of including primer components in cement base

This study investigated the efficacies of adhesive resin cements (Clearfil SA Luting, Maxcem, G-CEM, RelyX Unicem Clicker, Vitremer Paste) for bonding to Ag-Pd-Cu-Au alloy not surface-pretreated with metal primer. For control, Panavia F 2.0 -developed for use with a proprietary metal primer, Alloy Primer- was tested with and without metal primer application. Pairs of alloy disks (10.0 and 8.0 mm in diameters, 3.0 mm thickness) were air-abraded with alumina and bonded with one of the cements. Shear bond strengths (SBSs) were measured before and after 50,000 times of thermocycling. Among Maxcem, RelyX Unicem Clicker and the control, there were no statistical differences in SBS before and after thermocycling. After thermocycling, Clearfil SA Luting exhibited the highest SBS among all the cements. Results showed that Clearfil SA Luting, Maxcem, and RelyX Unicem Clicker were efficacious for bonding to Ag-Pd-Cu-Au alloy after air abrasion surface treatment for the latter.

A nine-year clinical case study of a resin-bonded fixed partial denture seated on the maxillary anterior teeth

PATIENT

This report describes the longevity of a resin-bonded fixed partial denture (RBFPD). This denture was seated on the maxillary anterior teeth with minimal tooth preparation. The RBFPD was cast from a silver-palladium alloy (Castwell M.C. 12), and the pontic was veneered with an indirect composite material (Estenia). The retainers were primed with a metal conditioner (V-Primer) and seated with a tri-n-butylborane initiated adhesive resin (Super-Bond C&B). After an observation period of eight years, a fracture occurred in the incisal edge of the central incisor abutment. The fractured area was restored with light-polymerizing composite resin and the anterior guidance was re-adjusted.

DISCUSSION

RBFPD abutment teeth with deep vertical overlap should be carefully prepared to avoid abutment tooth fracture.

CONCLUSION

The clinical performance of the RBFPD made from a silver-palladium-copper-gold alloy was sufficient when seated with tri-n-butylborane initiated adhesive resin after surface modification using vinyl-thiol primer.

CLINICAL SIGNIFICANCE

The use of vinyl-thiol primer and tri-n-butylborane initiated adhesive resin is a clinically reliable bonding system for seating resin-bonded fixed partial denture (RBFPD) made from a silver-palladium-copper-gold alloy. The RBFPD, based on a reliable bonding system, can clinically function for a long time, even if the vertical overlap of the abutment teeth is excessive.

[Specific bonding technics]

Bonding is a major component of our therapeutic arsenal. We routinely bond attachments to enamel as well as to other surfaces including dentin, ceramic, acrylic, steel, amalgam, and gold, especially for adult patients. This procedure poses certain technical problems for which adapted and specific technical protocols can provide solutions.

Fatigue of dentin-composite interfaces with four-point bend

OBJECTIVES

The objective was to determine the fracture and cyclic fatigue properties of composite-dentin beams bonded with a self-etching adhesive in four-point bend.

METHODS

Beams of rectangular cross-section were shaped to a size of approximately 0.87mmx0.87mmx10mm and placed in a four-point bending apparatus, with the loading points 1.8 and 7.2mm apart, with the interface centered between the inner rollers. Cyclical loading was performed in Hanks' Balanced Salt Solution at 25 degrees C, with forces between 54% and 99% of the bending strength of the bonded beams.

RESULTS

Solid dentin and solid composite beams [n=6] had bending strengths of 164.4 and 164.6MPa, respectively, under monotonically increasing loads. Bonded beams [n=6] had strengths of 90.6MPa. No significant difference was found between solid composite and solid dentin beams, the bonded beams were different (ANOVA, p<0.0001) With long-term cycling, stresses below 49MPa were tolerated for 10(6) cycles, but with increasing stress up to 90MPa, beams failed earlier, demonstrating that subcritical fatigue cycling will eventually cause failure.

SIGNIFICANCE

Fatigue may be a significant mechanism of dentin-composite bond degradation.

Effect of noble metal adhesive systems on bonding between an indirect composite material and a gold alloy

In this study, the bond strength between an indirect composite and a gold alloy was determined for the purpose of evaluating noble metal bonding systems. A single liquid primer designed for conditioning noble metal alloys (Infis Opaque Primer) and tri-n-butylborane-initiated adhesive resins (Super-Bond C & B), with or without the powder component, were assessed. Cast gold alloy disks (Casting Gold type IV) were air-abraded with alumina, followed by six surface preparations, and were then bonded with a light-activated composite material (New Metacolor Infis). Shear testing was performed both before and after thermocycling for evaluation of bond durability. The results showed that three primed groups improved post-thermocycling bond strengths compared to each of the corresponding unprimed groups (P < 0.01). The bond strength was reduced for all six groups by the application of thermocycling (P < 0.01). After thermocycling, the group primed with the Infis Opaque Primer material and bonded with the Super-Bond C & B resin exhibited the greatest bond strength (23.4 MPa). The Infis Opaque Primer and Super-Bond bonding system increased the post-thermocycling bond strength of the control group by a factor of approximately ten. This simple technique is applicable in the fabrication of composite veneered restorations and cone-telescope dentures.