Comparative Evaluation of the Fracture Resistance of Two Different Fiber-reinforced Composite Restorations with Particulate Filler Composite Restorations

Comparing fracture resistance on bovine incisors restored by tooth fragment reattachment versus direct composite restoration techniques

BACKGROUND/AIM

Anterior teeth are prone to traumatic dental injuries (TDIs). Although a number of techniques ranging from original tooth fragment reattachment (TFR) to direct composite restoration (DCR) can be used to restore uncomplicated crown fractures, there is no consensus on which method is best. The purpose of this study was to investigate the fracture resistance of bovine incisors restored by two different techniques (TFR and DCR) in three different fracture models.

MATERIALS AND METHODS

Sixty extracted bovine lower incisors were randomly divided into three groups (n = 20). Angle, oblique, or transverse sections of all the teeth in a group were prepared by using a disk. The cut surfaces were scanned, and the cross-sectional areas (CSA) of the enamel and dentin were measured. Half the teeth in each group were restored by DCR (n = 10) and the other half by TFR (n = 10). The forces required to fracture the restored teeth were then measured using a Universal testing machine, and the fracture modes were analyzed (cohesive, adhesive, or mixed).

RESULTS

No statistically significant differences between the TFR and DCR restorations were detected for total and enamel CSAs in any of the restoration shapes (p > .067). The fracture forces required to break DCR angle and transverse restorations were significantly greater than for the corresponding shapes restored with TFR (p < .033). However, the difference in the forces needed to fracture oblique section restorations by DCR or TFR was not statistically significant (p = .239), despite a similar trend (143.4 ± 51 N and 120.9 ± 25 N, respectively).

CONCLUSION

This study revealed that a greater force is required to fracture teeth restored by the DCR than by the TFR technique, especially for a transverse section. This demonstrates that restoring a fractured tooth provides a superior outcome compared to reattaching the fractured fragment.

Biomimetic approach to strengthen the incisal fracture composite build-up: an in vitro study

OBJECTIVE

Incisal composite build-up shows a high failure susceptibility. The incorporation of fiber-reinforced composite (FRC) during composite restoration could improve its strength. Hence the study was planned to compare the effect of various positions of FRC on the strength of composite resin incisal build-ups.

METHODS

In maxillary incisors (n = 90), 3 mm of the incisal edge was cut and teeth were categorized into three groups based on the location and number of fibers used during incisal composite build-up - Group I: composite resin; Group II: composite resin and a single fiber palatally and Group III: composite resin along with two fibers palatally.

RESULTS

The data showed that group II had the maximum load-bearing values followed by group I and group III.

CONCLUSION

Within the confines of our study, it can be concluded that the addition of FRC to the conventional incisal composite build-up increased the overall strength restoration. Such composite restoration reinforced with a single fiber on the palatal side showed the highest load-bearing capacity compared to two fibers reinforced and unreinforced composites. The common mode of failure in group I was in composite resin, in two fibers reinforced at fibers-composite junction, and in one fiber reinforced composite was in the remaining part of the tooth.

Comparison of fiber reinforcing methods of composite resin: A flexural strength and stereo microscopy study

This study aimed to compare the effect of fiber reinforcing methods on the flexural strength and failure modes of indirect composite resins. Based on the reinforcement methods, the bar specimens (3 × 3 × 25 mm) were divided into five groups (n = 20). Glass or polyethylene fibers were used for reinforcement of indirect composite resins. Fibers were either light polymerized and mixed with indirect composite resin or mixed with indirect composite resin after resin application and polymerized together. Indirect composite resin without fiber reinforcement was used as control. All five types of specimens were stored in distilled water at 37°C for 24 h. Half of the specimens were additionally thermocycled. Then the specimens were tested in a three-point bending test. Failure types were examined and categorized by using stereo microscope. The data were analyzed using two-way ANOVA and Tukey HSD test. Flexural strength was found to be significantly higher for fiber-reinforced indirect resin composites than control. However, the fiber-reinforced groups did not present any significant difference. Analysis revealed aging does not affect the flexure strength of fiber reinforcement of indirect composite resin. The study concluded that the flexure strength of indirect composite resins was improved with fiber reinforcement. Different fiber reinforcement methods demonstrated similar effects on the flexure strength of indirect composite resin. Reinforcement with glass or polyethylene fibers presented the potential to improve the mechanical properties of indirect composite resins. RESEARCH HIGHLIGHTS: Flexural strength of indirect composite resins are affected by the reinforcement of composites with glass or polyethylene fibers. Aging with thermocycling has no effect on the flexural strength of the indirect composite resins, however can cause catastrophic failures in material.

Evaluation of Fracture Strength of Fiber-Reinforced Direct Composite Resin Restorations: An In Vitro Study

This in vitro study aimed to compare the fracture strength of direct non-reinforced class II composite resin restorations and polyethylene fiber-reinforced restorations, and also to investigate the influence of the locations of polyethylene fibers within the cavity on the fracture strength. Sixty freshly extracted human teeth were disinfected and prepared (class II cavity design). The teeth were assigned randomly into four groups (n = 13). Group I (control) was restored with nano-hybrid composite resin. The other three experimental groups were restored with the same composite resin material reinforced by polyethylene fibers (Ribbond) at different locations. Fibers were placed either on the axial wall (Group II), on the gingival floor (Group III), or on the axial wall and pulpal/gingival floor (Group IV) of the proximal cavity. All the teeth were subjected to thermocycling to simulate the oral environment. The fracture strength was measured using a universal testing machine. Group IV had the highest mean fracture strength at maximum load (148.74 MPa), followed by Group II (140.73 MPa), Group III (136.34 MPa), and Group I (130.08 MPa), with a statistically significant difference from the control group (p = 0.008) but not between groups II and III.

Comparative Evaluation of the Influence of Different Sports/Energy Drinks and Alcoholic Beverages on the Surface Roughness of Three Different Flowable Esthetic Restorative Materials: An In Vitro Analysis

Objective:

This study aimed to evaluate the surface roughness of three flowable esthetic restorative materials after exposure to sports/energy drinks and alcoholic beverages.

Materials and Methods:

A total of 210 specimens of dimension (2cm diameter and 2 mm thickness) with giomer, compomer, and composite (70 samples with each esthetic material) were made with the help of plastic rings. The prepared samples were tested in six experimental sports/energy drinks (beer, whiskey, vodka, Gatorade, Red Bull, and Sting) and distilled water was considered as the control group. Profilometric analyses of all samples were recorded before immersing into the experimental and control solutions. Then, the samples were stored in the experimental and control group solutions for 5min for 30 days. The profilometric analysis was repeated after 30 days and records were statistically analyzed.

Results:

Flowable composite showed the minimum surface roughness, whereas the flowable compomer showed the maximum surface roughness in the present test conditions. When the erosive potential of the test solutions was evaluated, surface roughness values were more for sports/energy drinks when compared to that of alcoholic beverages.

Conclusion:

All the sports/energy drinks and alcoholic beverages evaluated in this study altered the surface roughness of the tested restorative materials. The effects ranged from slight to a markedly negative impact on the surface roughness of the test restorative materials.

Comparative evaluation of the effects of different methods of post space preparation in primary anterior teeth on the fracture resistance of tooth restorations

Background. Severely damaged teeth do not have adequate structure to support the composite crown; therefore, use of the canal space has been suggested to increase retention. Furthermore, the effect of post space irrigation protocols on the fracture resistance of the primary anterior teeth has not definitely been studied in postoperative modalities. This study compared the fracture resistance of restorations of primary anterior teeth following irrigation of the post space with sodium hypochlorite and chlorhexidine with and without application of burs.

Methods. Ninety-four extracted primary anterior teeth were selected. Root canal treatments were carried out, 4 mm of the post space was left empty and 1 mm was regarded as a bed. The post space was prepared with and without a bur and the irrigation procedures were carried out with 0.2% chlorhexidine and 2.5% sodium hypochlorite solutions. Composite posts were inserted into the canals and the crowns were restored. Following composite etching and light-curing, the fracture resistance of the restored teeth was determined by a universal testing machine.

Results. In the sodium hypochlorite group, fracture resistance of the teeth was 376.8±107.29 N and 475.5±186.89 N without and with bur preparation, respectively. For chlorhexidine protocol, the values were 370.88±175.46 N and 430.85±178.22 N without and with bur preparation, respectively. The effect of irrigating material was not significant; however, the bur and irrigating preparation significantly increased the fracture resistance of the restored teeth (P=0.02).

Conclusion. Post space irrigation with 0.2% chlorhexidine or 2.5% sodium hypochlorite did not significantly affect the fracture resistance of primary anterior teeth in the post treatment modality.