Short Fiber-reinforced Composite Resin Research Articles

Short Fiber Reinforced Composite: a New Alternative for Direct Onlay Restorations

Objectives: To determine the static load-bearing capacity of direct composite onlay restorations made of novel filling composite resin system which combines short fiber-reinforced composite resin (FC) and conventional particulate filler composite resin (PFC).Methods: Three groups of onlay restorations were fabricated (n = 8/group); Group A: made from conventional particulate filler composite resin (Z250, 3M-ESPE, USA, control), Group B: made from short fiber-reinforced composite resin (EverX posterior, StickTeck Ltd, member of GC group, Turku, Finland) as substructure with 1 mm surface layer of PFC, Group C: made from FC composite resin. The specimens were incrementally polymerized with a hand-light curing unit for 80 s before they were statically loaded with two different sizes (3 & 6 mm) of steel ball until fracture. Failure modes were visually examined. Data were analyzed using ANOVA (p = 0.05).Results:ANOVA revealed that onlay restorations made from FC composite resin had statistically significantly higher load-bearing capacity (1733 N) ( p < 0.05) than the control PFC composite resin (1081 N). Onlays made of FC composite resin with a surface layer of PFC gave force values of 1405 N which was statistically higher than control group ( p < 0.05). No statistically significant difference was found in the load-bearing capacity between groups loaded by different ball sizesSignificance: Onlay restorations combining base of short fiber reinforced composite resin as substructure and surface layer of conventional composite resin displayed promising performance in high load bearing areas.

Erratum to: Creep of experimental short fiber-reinforced composite resin

Erratum to: Creep of experimental short fiber-reinforced composite resin

Preliminary Clinical Evaluation of Short Fiber-Reinforced Composite Resin in Posterior Teeth: 12-Months Report

This preliminary clinical trial evaluated 12 month clinical performance of novel filling composite resin system which combines short fiber-reinforced composite resin and conventional particulate filler composite resin in high stress bearing applications. A total of 37 class I and II restorations (compound and complex type) were placed in 6 premolars and 31 molars. The restorations were reviewed clinically at 6 months (baseline) and 12 months using modified USPHS codes change criteria for marginal adaptation, post-operative sensitivity, pulpal pain and secondary caries criteria. Photographs and x-rays were obtained for restorative analysis. Results of 12 months evaluation showed 5 restorations having little marginal leakage (B score) and 1 patient had minor pulpal symptom and post-operative sensitivity (B score). No secondary caries or bulk fracture was detected. The majority of restorations exhibited A scores of the evaluated criteria. After 12 months, restorations combining base of short fiber reinforced composite resin as substructure and surface layer of hybrid composite resin displayed promising performance in high load bearing areas.

Creep of experimental short fiber-reinforced composite resin

The purpose of this study was to investigate the reinforcing effect of short E-glass fiber fillers oriented in different directions on composite resin under static and dynamic loading. Experimental short fiber-reinforced composite resin (FC) was prepared by mixing 22.5 wt% of short E-glass fibers, 22.5 wt% of resin, and 55 wt% of silane-treated silica fillers. Three groups of specimens (n=5) were tested: FC with isotropic fiber orientation, FC with anisotropic fiber orientation, and particulate-filled composite resin (PFC) as a control. Time-dependent creep and recovery were recorded. ANOVA revealed that after secondary curing in a vacuum oven and after storage in dry condition for 30 days, FC with isotropic fiber orientation (1.73%) exhibited significantly lower static creep value (p<0.05) than PFC (2.54%). For the different curing methods and storage conditions evaluated in this study, FC achieved acceptable static and dynamic creep values when compared to PFC.

Direct restoration of severely damaged incisors using short fiber-reinforced composite resin

Objectives The aim of this in vitro study was to evaluate the static load-bearing capacity and the failure mode of endodontically treated maxillary incisors restored with complete crowns made of experimental composite resin (FC) with short fiber fillers, with and without root canal posts. Further aim was to evaluate the effect of fiber-reinforced composite resin (FRC) on the failure mode of the restoration. Material and methods The experimental composite resin (FC) was prepared by mixing 22.5 wt.% of short E-glass fibers (3 mm in length) and 22.5 wt.% of semi-interpenetrating polymer network (IPN) resin with 55 wt.% of silane treated silica fillers. The clinical crowns of 30 human extracted maxillary incisors were sectioned at the cemento-enamel junction. Five groups of direct complete crowns were fabricated ( n = 6); Group A: made from particulate filler composite resin (PFC) (Grandio Caps, VOCO, control), Group B: PFC with fiber post (everStick, StickTeck), Group C: made from PFC with everStick fiber post and FRC-substructure, Group D: made from FC, Group E: made from FC with FRC-substructure. The root canals were prepared and posts were cemented with resin cement (ParaCem Universal). All restored teeth were stored in water at room temperature for 24 h before they were statically loaded with speed of 1.0 mm/min until fracture. Data were analyzed using ANOVA ( p = 0.05). Failure modes were visually examined. Results ANOVA revealed that restorations made from experimental fiber composite resin had higher load-bearing capacity (349 N) ( p < 0.05) than the control restorations (173 N). No significant difference was found in load-bearing capacity between restorations reinforced with FRC-substructure and those without ( p > 0.05). Conclusions Restorations made from short glass fiber containing composite resin with IPN–polymer matrix showed better load-bearing capacity than those made with either plain PFC or PFC reinforced with fiber post.

Polymerization shrinkage of experimental short glass fiber-reinforced composite with semi-inter penetrating polymer network matrix

Objectives The aim of this study was to determine the magnitude of short fiber-reinforced composite resin, with a semi-IPN-polymer matrix, on polymerization resin shrinkage-strain, shrinkage stress and marginal microleakage of the restoration. Materials and methods Experimental composite FC resin was prepared by mixing 22.5 wt.% of short E-glass fibers, 22.5 wt.% of IPN-resin and 55 wt.% of silane treated silica fillers using a high speed mixing machine. As control material, commercial particulate filler composite resin (PFC) was used. Polymerization shrinkage-strain and stress of the specimens ( n = 5) were measured using the bonded-disc technique and tensilometer, respectively with respect to time. FC composite and PFC were placed incrementally in class II cavities sized 4 mm × 4 mm × 6 mm ( n = 8/group) using total-etch adhesive system according to manufacturer's instructions. After the class II restorations were completed, the specimens were finished and polished, thermocycled, stained, sectioned, and viewed under a stereo-microscope for leakage at occlusal/enamel and gingival/dentin margins. The data were analyzed using ANOVA. Results ANOVA revealed that restorations made from experimental FC composite had a significantly lower shrinkage stress and microleakage than those made from PFC ( p < 0.05). The data show that gingival margins had higher microleakage than that obtained from occlusal margins of restorations ( p < 0.05). Conclusions The use of short fiber filler with semi-IPN polymer matrix reduced polymerization shrinkage stress and microleakage compared to a conventional restorative composite.