Effect of Salvadora persica on resin-dentin bond stability

BACKGROUND

The stability of resin-dentin interfaces is still highly questionable. The aim of this study was to evaluate the effect of Salvadora persica on resin-dentin bond durability.

MATERIALS AND METHODS

Extracted human third molars were used to provide mid-coronal dentin, which was treated with 20% Salvadora persica extract for 1 min after acid-etching. Microtensile bond strength and interfacial nanoleakage were evaluated after 24 h and 6 months. A three-point flexure test was used to measure the stiffness of completely demineralized dentin sticks before and after treatment with Salvadora persica extract. The hydroxyproline release test was also used to measure collagen degradation by endogenous dentin proteases. Statistical analysis was performed using two-way ANOVA followed by post hoc Bonferroni test and unpaired t-test. P-values < 0.05 were considered statistically significant.

RESULTS

The use of Salvadora persica as an additional primer with etch-and-rinse adhesive did not affect the immediate bond strengths and nanoleakage (p > 0.05). After 6 months, the bond strength of the control group decreased (p = 0.007), and nanoleakage increased (p = 0.006), while Salvadora persica group showed no significant difference in bond strength and nanoleakage compared to their 24 h groups (p > 0.05). Salvadora persica increased dentin stiffness and decreased collagen degradation (p < 0.001) compared to their controls.

CONCLUSION

Salvadora persica extract pretreatment of acid-etched dentin preserved resin-dentin bonded interface for 6 months.

CLINICAL SIGNIFICANCE

Durability of resin-dentin bonded interfaces is still highly questionable. Endogenous dentinal matrix metalloproteinases play an important role in degradation of dentinal collagen within such interfaces. Salvadora persica may preserve resin-dentin interfaces for longer periods of time contributing to greater clinical success and longevity of resin composite restorations.

Cross-linked dry bonding: A new etch-and-rinse technique

OBJECTIVE

To determine if acid-etched, cross-linked dentin can be dehydrated without lowering bond strength below that of cross-linked wet-bonded dentin in vitro.

METHODS

Using extracted human third molars, control acid-etched dentin was bonded with Single Bond Plus, using either the wet- or dry-bonding technique. Experimental acid-etched dentin was treated with 5mass% grape seed extract (GSE) in different solvents for 1min before undergoing wet vs dry resin-dentin bonding with Single Bond Plus. Completely demineralized dentin beams were treated with 5% GSE for 0, 1 or 10min, before measuring stiffness by 3-point flexure. Other completely demineralized beams were treated similarly and then incubated in buffer for 1 week to measure the collagen solubilization by endogenous dentin proteases.

RESULTS

24h microtensile bond strengths (μTBS) in wet and dry controls were 53.5±3.6 and 9.4±1.8MPa, respectively (p<0.05). 5% GSE in water gave μTBS of 53.7±3.4 and 39.1±9.7MPa (p<0.05), respectively, while 5% GSE in ethanol gave μTBS of 51.2±2.3 and 35.3±2.0MPa (p<0.05). 5% GSE in 5% EtOH/95% water gave wet and dry μTBS of 53.0±2.3 and 55.7±5.1MPa (p>0.05). Cross-linking demineralized dentin with 5% GSE increased stiffness of dentin and decreased collagen degradation (p<0.05).

SIGNIFICANCE

5% GSE pretreatment of acid-etched dentin for 1min permits the dentin to be completely air-dried without lowering bond strength.