Clinical Behaviour and Marginal Sealing of Bulk-Fill Resin Composite Restorations Using Light Amplified High-Intensity LEDs Curing: A Randomized Controlled Clinical Trial

Abstract

BACKGROUND: Delivering sufficient intensity output of curing lights is mandatory to ensure optimum cure and clinical success of bulk-fill resin composite restorations and to avoid undesirable clinical outcomes.
 AIM: To evaluate the effectiveness of using light amplified high intensity LED curing on the clinical performance and marginal sealing of posterior bulk-fill resin composite restorations.
 MATERIAL AND METHODS: This study was designed as a randomised, controlled, double-blind, Unicenter, parallel, two arms, superiority trial with 1:1 allocation ratio. Adult patients who required posterior tooth-coloured restorations were asked to participate in this trial. All participants signed written informed consent after being completely aware of the settings of the study. The participants who fulfilled the eligibility criteria were divided into two groups according to the type of light curing mode used. Adhesive compound proximal cavities were prepared. All restorative materials were applied according to the respective manufacturer’s instructions. Assessments of the restorations were done at baseline (one week after placement of the restoration), after 6 months and after 12 months using the modified US Public Health Service (USPHS) criteria. For quantitative assessment of the marginal sealing, resin replicas were analysed using scanning electron microscopy. Statistical analysis was done using Chi-square, Mann Whitney, independent t-test and dependent t-tests.
 RESULTS: There were no statistical differences between the two groups for the tested clinical parameters along the study periods. For marginal analysis, there were no statistical differences between the intervention and control group at baseline and six months (p-value = 0.347 and 0.516) respectively. At 12 months the control group showed statistically significant higher percentages (p-value = 0.031).
 CONCLUSION: Light amplified high-intensity curing units have clinical performance comparable with the conventional LED.

The Effect of Irradiance on the Degree of Conversion and Volumetric Polymerization Shrinkage of Different Bulk-Fill Resin-Based Composites: An In Vitro Study

“…33 In a randomized clinical study, the effectiveness of using high-intensity LED curing light on the clinical performance of bulk-fill RBC restorations was evaluated; no difference in performance was observed between the conventionally used intensity and high-intensity light used for curing the restorations. 34 All of the tested RBCs in this study had a VPS ranging from 2.090 to 3.193%, which is an acceptable value. 35 Furthermore, the use of high-intensity curing light for 20 seconds or low-intensity curing light for 40 seconds had no significant effect on the VPS.…”

Short-term effect of adhesive system on clinical performance of bulk fill composite

“…Bulk fill composites are a promising clinical approach for tooth restoration due to the enhanced polymerization process and reduced clinical time. Thus, the clinical evaluation of this restorative material under different techniques allows the standardization of appropriate protocols 4 . The results of the present study showed similar clinical performance of restorations made under different adhesive systems, with slight differences that were not clinically relevant.…”

“…The improvement of dental materials, as well the increased demand for esthetic treatments by patients, have improved the development of less invasive restoration techniques and the use of composites with enhanced biomechanical and esthetic properties [1][2][3] , even for posterior teeth 4 . However, the polymerization shrinkage and the development of stress in the tooth-restoration interface, still being an important clinical problem that can degrade the adhesive layer, create cracks, and, consequently lead to treatment failure 5 .…”

“…In this sense, different incremental techniques have been developed to reduce the material shrinkage 6,7 . Although an increment thickness of 2 mm of composite has been suggested for tooth restoration to reduce this effect 4 , this approach can increase the clinical time 8 . Therefore, to reduce the polymerization shrinkage effect different materials and techniques have been suggested, among them, bulk fill composites 4 .…”

“…These composites are available in two forms: low (flow) and high viscosity, in terms of organic matrix composition 12 . Overall, clinical trials have compared the use of bulk fill and conventional composites showing similar clinical performance for both materials 13 , but with a better marginal adaptation for bulk fill material 4 . However, different clinical protocols have been tested by these studies, and differences in the experimental designs make it hard to compare between the materials and techniques used.…”