Comparing direct restorations utilising fiber reinforced materials in MOD cavities – pilot study

Abstract

Objectives: The aim of this preliminary in vitro study was to compare the efficiency of different direct restorative techniques
for restoring class II. MOD cavities in molar teeth.
Methods: seventy two mandibular third molars were divided into 6 groups (n = 12). Except for the control group (intact
teeth, Group 1), in all other groups deep MOD cavities were prepared. The cavities were restored by different direct
restorative techniques (Group 2–6). Group 2: conventional resin-based composite (RBC), Group 3: replacing the missing
dentine with short-fiber reinforced composite (SFRC) and occlusally covered with 1 mm RBC, Group 4: fiber net inserted
in a buccal to lingual direction placed on the base of the cavity and finished with SFRC and RBC, Group 5: SFRC
with fiber net placed on top of it in a buccal to lingual direction and finished with RBC, Group 6: fiber net placed circumferentially
into the cavity and finished with SFRC and RBC. The specimens were submitted to static load to fracture test.
Results: the intact teeth (Group 1) yielded the highest fracture resistance values among all groups. There was no statistically
significant difference between Group 1, 3 and 6. In all groups, the fracture pattern was mostly restorable, except
for Group 2 showing non restorable fractures predominantly.
Conclusions: The application of fiber net circumferentially with SFRC produced fracture resistance values closly resembling
the values with intact teeth. Cavities restored with conventional RBC filling showed significantly worse values
regarding fracture resistance compared to intact teeth.