# The Effect of Adhesive Systems on the Bond Strength of Directly Bonded Fixed Partial Dentures Using Artificial Teeth: An In Vitro Study

## TL;DR

This study compared two adhesives for bonding artificial teeth and found one provided significantly stronger and more reliable bonds.

## Contribution

The study introduces a direct comparison of self-curing and light-curing adhesives for bonding artificial teeth in fixed dentures.

## Key findings

- Self-curing resin cement showed significantly higher shear bond strength than light-curing flowable resin composite.
- Self-curing resin cement exhibited no adhesive failure, while light-curing composite primarily failed adhesively.
- The presence of a retentive groove had no significant effect on bond strength with self-curing resin cement.

## Abstract

Objective

This study aimed to evaluate the effect of different adhesive systems on the bond strength of a directly bonded fixed partial denture (DBFPD) utilizing artificial teeth through shear bond strength (SBS) testing and a DBFPD model experiment.

Materials and methods

Two different adhesive systems: self-curing resin cement (SRC) (Super Bond Universal; Sun Medical, Moriyama, Japan) and light-curing flowable resin composite (LFRC) (G-Fix; GC, Tokyo, Japan) were applied to two different hybrid resin artificial teeth: Duracross Physio (Nissin, Kyoto, Japan) and Endura Posterio (Shofu, Kyoto, Japan). The SBS of the adhesive systems to artificial teeth was evaluated using a universal testing machine (AGX-1kN, Shimadzu, Kyoto, Japan). Subsequently, the failure modes were assessed using a stereomicroscope (VHX-970F, Keyence, Osaka, Japan). An experimental model comprising a lower mandibular incisor artificial tooth as a pontic was utilized to evaluate the bond strength of these adhesive systems, with or without a retentive groove.

Results

The SRC group (≈20 MPa) exhibited significantly higher SBS than the LFRC group (≈10MPa), with no significant difference between artificial teeth types. Failure mode analysis showed no adhesive failure in the SRC group, while the LFRC group primarily failed adhesively. In the model experiment, SRC-fixed artificial teeth had the highest bond strength, unaffected by groove presence. The LFRC group with a groove showed slightly improved strength, but the increase was not statistically significant.

Conclusions

SRC demonstrated superior bond strength compared to LFRC for hybrid resin artificial teeth, regardless of filler percentage or retentive groove presence.