BENEFITS AND DRAWBACKS OF BULK-FILL DENTAL COMPOSITES: A SYSTEMATIC REVIEW

Nujud S.A. Edrees, BDS; Hadeel S. A. Amer, BDS; Khalid M. Abdelaziz, BDS, MDSc, PhD; Wafa Alajam, BDS, MSc, PhD

ABSTRACT

Introduction: Bulk-fill composites were recently introduced, the published literature about their physical and mechanical properties yield inconsistent or sometimes contradicting results. Therefore, in depth review of this literature could be a helpful guide for dentists to use these new promising restorative materials. This study aims to meticulously revise the previously published articles concerned about bulk-fill composites to highlight their benefit and drawbacks, regarding their physical and clinical properties. Methods: All articles published in English language and dated before Sept 2016, were eligible to be included in this review. Articles included the search terms in any fields were screened (5384 articles). After that, the duplicated and irrelevant studies were excluded based on their titles and abstracts (5339 excluded articles). Then, the full texts were retrieved for the other eligible articles to conduct in-depth screening for the tested properties of the bulk-fill composite (45 articles). Then, the exclusion of the irrelevant studies based on the full text of articles was done to yield finally included studies (32 articles). Then nine studies were excluded from 32 included studies; due to different measurement of outcomes that were not valid for comparisons with the other included studies, thus, the finally included studies were 23. Results: The depth of cure for flowable and paste-like composite was higher than that for conventional composite. Degree of conversion of flowable in comparison to conventional was contradicting, while paste like bulk fill was higher than condensable conventional composite. Polymerization shrinkage is higher or comparable in flowable bulk fill composite in comparison to that in the conventional composite, while in paste like composite the results was contradicting. The polymerization stress of flowable and paste-like bulk fill composite was lower than that of conventional composite. In regards to top hardness, most studies found it lower in flowable bulk fill composite in comparison to conventional composite, while in paste like composite the results was contradicting. The bottom surface hardness of flowable bulk fill composite was comparable or lower than that in conventional composite, while in paste like composite the results was contradicting. The flexure (transverse) strength of flowable bulk fill composite was lower than conventional composite, while in paste like composite the flexural strength was comparable with conventional composite. The compressive strength and tensile strength of flowable and paste like bulk fill composite was lower than that in conventional composite. The bond strength to dentine in flowable bulk fill composite was comparable or higher than conventional depend on increase in the filling thickness, no study assesse the bond strength in paste-like composite. In marginal adaptation, no comparison to the conventional composite was made. Concerning micro-leakage, the flowable bulk fill composite was comparable to the conventional composite in enamel, but lower than conventional in dentine. In paste like composite, no comparison was made with conventional composite. Conclusions: Regarding the chemical curing properties such as depth of cure and degree of conversion, the bulk fill composite (either flowable or paste-like) were superior to the conventional composite. In regards to the mechanical properties such as top hardness, bottom hardness, flexural strength, compressive strength and tensile strength, the flowable bulk fill composite tend to be inferior to the conventional composite. While the results were contradicting in regards to paste-like bulk fill composite. The polymerization stress was lower in the flowable and paste-like bulk fill composite in comparison to the conventional composite, while the results were inconsistent in regards to the polymerization shrinkage. Concerning the bond strength and micro-leakage, they tend to be superior in the flowable bulk fill composite than conventional composite, but more studies are required to elaborate this area.

Keywords: Composite, Bulk-fill, Flowable, Paste-like, Strength, Cure.