Preheated Composites Research Articles

Evaluation of pre-heated composite resins with soft-start polymerization and conventional composite restorations in class-I carious lesions – A randomized clinical trial

BackgroundBy increasing fluidity and conversion, pre-heated composites enhance adaptability and strength, while soft-start polymerization decreases internal stresses. AimOver a period of a year, this split-mouth design, randomized controlled clinical trial (RCT) compared pre-heated composites with soft-start polymerization to conventional composites in class-I lesions, with the goal of improving restoration outcomes. Methodsand Findings: Immediately following ethical approval and registration with CTRI, 37 patients with in-formed permission who met specified inclusion and exclusion criteria for class-I lesions were chosen for enrollment. Using a 1:1 ratio, teeth were randomly assigned to Group-A (pre-heated composite with soft-start polymerization) or Group-B (traditional composite restoration). At three-time intervals, the evaluation was blinded and calibrated using Modified United States Public Health Service (USPHS) criteria: baseline, six-month, and one-year marks. Statistical analysis was performed using SPSS 21.0 and the Mann-Whitney U test for inter-group comparisons and the Friedman test for intra-group comparisons. InterpretationPre-heated composites with soft-start polymerization performed better in terms of marginal adaptation with a statistically significant difference (p = 0.019) and in terms of color match they performed better clinically (p = 0.062) at 12 months. Other variables like marginal discolouration, sec-ondary caries, anatomic form, post-operative sensitivity, surface texture and retention showed no statistically significant difference (p < 0.05). Pre-heated composites with soft-start mode performed marginally better than nanofilled composites. However, both techniques can be used to successfully restore simple class-I carious lesions.

Preheating effect on microhardness and depth of cure of three bulk-fill composite resins: An in vitro study

ABSTRACT Aim: The aim of this in vitro study was to evaluate and compare the effect of preheating on microhardness and depth of cure of three bulk-fill composite resins. Methods: Three bulk-fill composite resins were used; Group I: Filtek Bulk Fill, Group II: Beautifil Bulk Restorative and Group III: Tetric N Ceram Bulk Fill. Further each group was divided into two subgroups, Sub Group A: Discs were prepared using nonheated composite, Sub Group B: Discs were prepared using preheated composite. A total of 60 disc shaped specimens were prepared and microhardness (Vickers Microhardness Number [VHN]) of the top and bottom surfaces of the disc specimens were measured by Vickers microhardness tester. The ratio of the bottom surface VHN to the top surface VHN was used to calculate the depth of cure. Results: Preheated groups showed higher VHN values as compared to nonheated groups. Group II showed higher VHN value as compared to Group I in both subgroups. Group III showed the least VHN values in both subgroups. VHN values were maximum on top surfaces and minimum on the bottom surfaces for all the groups. It was found that the highest depth of cure was 0.71 while lowest depth of cure was 0.62. Conclusion: Preheating resulted in higher VHN values compared to nonheating. Top surface VHN values were better as compared to bottom surface VHN values for all groups. The depth of cure showed satisfactory results for all groups.

Preheating and "snow-plow" composite application technique affect double bond conversion but not bond strength to dentine.

To measure degree of conversion (DC) of a flowable composite, microtensile bond strength (MTBS) to dentine in the snow-plow technique with/without preheating and temperature in the preheated composite. For DC, snow-plow specimens of Filtek Ultimate Flowable (Flow) and Filtek Bulk Fill (Bulk) (3M) were prepared by light-curing composites simultaneously in standardized molds while in control groups light-curing was separate. DC of Flow was measured using micro-Raman spectroscopy. For MTBS, specimens were prepared on dentine of human extracted molars by simultaneous (snow-plow) or separate (control) light-curing. MTBS was measured using a universal testing machine after 24 h and 6 months. Data were analyzed using ANOVA with Tukey's post hoc (α = 0.05). Increased curing time significantly increased DC in snow-plow from 13.4% ± 11.6% (10 s) to 31.8% ± 4.4% (40 s) albeit significantly lower than controls (p < 0.05). Preheated Bulk improved conversion in snow-plow (44.3% ± 1.7%) and control (50.5% ± 2.6%) (p < 0.05). No significant differences occurred in MTBS between groups (p > 0.05). MTBS values ranged between 66.7 ± 8.4 MPa (snow-plow group_21°C_baseline) and 54.1 ± 15.8 MPa (control_21°C_long-term). Temperature in the preheated Bulk dropped to ~38°C after 30 s. Snow-plow technique, irrespective of preheating, resulted in lower DC of Flow than separate light-curing of composite increments. Snow-plow, irrespective of preheating, resulted in similar initial and long-term MTBS to dentine. Clinicians with preference for flowable composite liners in Class II restorations should be aware that the snow-plow technique of simultaneous light-curing of flowable and bulk-fill composite increments affects monomer-to-polymer conversion, albeit no effect on immediate, and long-term bonding to dentine was detected. Preheating sculptable bulk-fill composite improves conversion of the flowable liner in the snow-plow technique but has no detectable effect on bond strength to dentine.

Clinical performance of bonded partial lithium disilicate restorations: The influence of preparation characteristics on survival and success

ObjectivesThe aim of this study was to investigate the influence of preparation characteristics on the survival, success, and clinical performance of partial indirect lithium disilicate restorations with immediate dentin sealing. MethodsThis retrospective clinical study evaluated partial indirect lithium disilicate restorations placed in conjunction with Immediate Dentin Sealing (IDS) in (pre)molar teeth between March 2018 and May 2021. The restorations were luted using pre-heated composite. The study focused on survival, success, and clinical performance, which was evaluated using the modified United States Public Health Service (USPHS) criteria. Results were analyzed using the Kaplan-Meier estimates, log-rank tests, and Fisher exact tests. ResultsPartial indirect lithium disilicate restorations (N = 454) were evaluated in 214 patients. The mean evaluation time was 37 months, with a cumulative survival rate of 99.2 % and a cumulative success rate of 97.6 %. Fourteen failures occurred, with endodontic pathology as the predominant failure mode, followed by secondary caries, debonding, and tooth fracture. No statistically significant influence of the preparation variables on survival and success was observed (p > .05). The short-term clinical performance was clinically acceptable in > 90 % of the evaluations. ConclusionsThis retrospective study on partial indirect lithium disilicate restorations in conjunction with IDS demonstrates survival and success rates of 99.2 and 96.7 % over a mean evaluation period of 37 months. A marked influence of the studied preparation characteristics on the survival, success and clinical performance of lithium disilicate partial restorations could not be demonstrated. Partial lithium disilicate restorations exhibit good clinical performance in >90 % of the cases. Clinical significanceThe results of this study suggest that preparation characteristics had no significant impact on the survival, success, and clinical performance of partial lithium disilicate restorations in conjunction with IDS. Results show good clinical performance and high survival and success rates, regardless of preparation characteristics.

Preheated Composite as an Alternative for Bonding Feldspathic and Hybrid Ceramics: A Microshear Bond Strength Study.

To evaluate the bond strength between alternative or conventional luting agents and indirect restorative materials. Blocks of a polymer-infiltrated ceramic network (PICN, Vita Enamic) and a feldspathic ceramic (FEL, Vita Mark II) were sliced and divided according to the luting agent: resin cement (PICN-RC, FEL-RC), flowable composite (PICN-FC, FEL-FC), or preheated composite (PICN-PH, FEL-PH). The ceramic surfaces were polished, etched with 5% hydrofluoric acid for 60 s, and then a silane layer was applied. Cylinders of the luting agents were built up on the ceramic surfaces. In half the samples, the microshear bond strength (µSBS) was tested after 24 h (baseline). The other half was tested after 5000 thermocycles (5°C-55°C) (aging). The failure modes were determined using a stereomicroscope, and the ceramic surfaces were analyzed using a scanning electron microscope. Data were statistically analyzed with two-way ANOVA. Thermocycling reduced the bond strength values of all experimental groups. Regarding FEL, the preheated composite obtained the highest results. Resin cement showed results similar to the flowable composite at baseline and after aging. The highest results of PICN were obtained from the preheated composite followed by resin cement and flowable composite. Significant differences among the three luting agents were observed before and after aging. The most frequent failures among the experimental groups were adhesive and cohesive in the ceramic. Bond strength results indicate that the preheated composite can be an alternative for adhesive cementation when applied on the tested feldspathic ceramic or PICN.

Effect of immediate dentin sealing on the fracture strength of indirect overlay restorations using different types of luting agents (A comparative in vitro study).

This study evaluates the effects of immediate dentin sealing (IDS) on the fracture resistance of lithium disilicate overlays using three different types of resin-luting agents (preheated composite, dual-cure adhesive resin, and flowable composite). Forty-eight maxillary first premolars of equal size were prepared using a butt joint preparation design. The teeth were separated into two primary groups, each with 24 teeth: Group DDS - delay dentin sealing (DDS) (non-IDS) teeth were not treated. Group IDS - dentin sealing was applied immediately after teeth preparations. Each group was subsequently separated into three separate subgroups of eight teeth. Subgroups DDS+Phc and IDS+Phc - cemented with preheated composite (Enamel plus HRi, Micerium, Italy), subgroups DDS+Dcrs and IDS+Dcrs - cemented with dual-cured resin cement (RelyX Ultimate, 3M ESPE, Germany), and subgroups DDS+Fc and IDS+Fc - cemented with flowable composite (Filtek Supreme Flowable, 3M ESPE, USA). The fracture resistance of each sample was evaluated using a test of a single load till failure, which was automatically recorded in Newton by a computer-controlled universal testing system. The fracture resistance of the subgroup IDS+Phc was the highest mean value, in which the overlay was cemented with preheated composite (1954 N), and the lowest mean was noted in the subgroup DDS+Fc, by which the overlay cemented with flowable composite without IDS (887 N). All IDS subgroups had a high mean fracture load. Both the Bonferroni test and the one-way ANOVA test identified a significant difference between all groups of 0.05. In general, teeth with IDS were stronger than teeth without IDS. When the preheated composite is used as a luting agent improves overall fracture resistance, followed by resin cement and flowable composite, respectively. However, the result showed that the ceramic overlays with and without IDS are strong enough to withstand the normal mastication force. Overlays was failed in a more catastrophic, irreparable mode of fracture than the clinical situation.

Accuracy of Direct Composite Veneers via Injectable Resin Composite and Silicone Matrices in Comparison to Diagnostic Wax-Up.

Purpose: To evaluate the discrepancy between the diagnostic wax-up and the resulting direct veneers using different matrices. Materials and method: A total of 48 identical misaligned models, 12 wax-up models and one ‘every other tooth’ wax-up model were 3D printed. Group 1: Transparent silicone matrices with holes for the injection of the flowable composite. Group 2: The same procedure as group 1, but the first three teeth were restored using the matrix constructed from the ‘every other tooth’ wax-up model. Group 3: Transparent silicone matrices cut for each tooth and preheated resin composite. Group 4: The same procedure as group 3, but the loaded matrix was placed first in the clear plastic tray, which was used for the matrix’s fabrication. Group 5: Wax-up models (control group). Scans from the veneers were superimposed with the scans from the wax-up and compared using the Patient Monitoring software. Measurements were made at the incisal, middle and cervical third. Kruskal-Wallis test and Dunn post-hoc test (p < 0.05) were used to analyze the results. Results: No statistically significant differences were found between groups 1 and 2 and the control. Group 3 was different from the control in the incisal and middle third, and group 4 was different in the cervical third. Conclusions: (1) Use of one or two matrices and the injection of flowable composite were accurate techniques. (2) Use of a matrix for each tooth combined with a pre-heated composite was the most inaccurate technique, but the use of the clear tray in combination with the matrix improved the accuracy.

Preheating of dental composite resins: A scoping review.

The aim of this scoping review was to analyze the available evidence on the preheating process and its effects on physicochemical properties of composite resins. A systematic search was performed in August 2021 using PubMed/Medline, Embase, Scopus, and ISI Web of Science databases and gray literature without language or date restriction. Inclusion criteria were in vitro studies that assessed the physicochemical properties and marginal adaptation of preheated composite. Exclusion criteria were studies with experimental composite, literature reviews, clinical studies. Data from selected studies were qualitatively analyzed. In total, 104 studies were found from which 39 were included. The most used composite resin was Filtek Z350 XT (3M/ESPE), preheated at 68°C in a Calset device (AdDent Inc., Danbury, CT, USA) for 5 or 15 min. Most studies showed decreased viscosity, increased conversion degree and microhardness of composite resins, and better marginal adaptation of direct and indirect restorations. Also, flexural strength was not affected, and data about bond strength were inconclusive due to heterogeneity among studies. The parameters used for preheating composite resins are heterogeneous. Preheating decreased viscosity, increased the conversion degree and microhardness of composite resins, and improved the marginal adaptation of direct and indirect restorations. The analysis of evidence showed a high heterogeneity among preheating protocols. Preheating may benefit the handling and physicochemical properties of composite resins.

Operator versus material influence on film thickness using adhesive resin cement or pre-heated resin composite.

There is a growing interest in using pre-heated composites instead of dual-cured cements when luting indirect restorations. This study evaluated the film thickness obtained from two pre-heated composites and two resin cements, by two different operators. The influence of the materials and the level of expertise of the operator were analyzed. Forty specimens of human dentin and composite discs were prepared and divided into four groups depending on the luting process. Each group was randomly equally divided to be handled by two operators with different levels of experience. Two of the initial four groups were luted using dual-cured cements and the two remaining groups using light-cured pre-heated composites. Specimen discs were cut after luting, and film thickness was measured using a Digital microscope. Data were analyzed using a 2-way ANOVA with the Holm-Sidak pairwise multiple comparison procedure (p < 0.05). Mean film thickness ranged from 156.16 ± 4.7 to 33.82 ± 0.7μm. Significant differences (p < 0.001) were noticed between expert and novice results with pre-heated composites. Within the limits of this study, using pre-heated composites as a luting cement requires a better level of expertise to achieve a clinically acceptable film thickness. Using pre-heated composites as luting agent for indirect restorations requires an experimented skill level to achieve a clinically recommended film thickness.

Improving bonding strength of injection Overmolded composites

AbstractThe overmolding of short fiber reinforced polymer compounds onto continuous fiber reinforced composite substrates provides design flexibility and the ability to tailor stiffness, strength, and damage tolerance for structural applications. In this work, a novel molding approach that enhances the bonding strength by mechanical interlocking is presented. The effectiveness of the proposed approach was validated by characterization of the bonding strength between a short glass fiber PP (SGFPP) composite overmolded onto a continuous glass fiber reinforced PP (CGFRPP) prepreg. Enhancement of the bonding strength was achieved by judiciously drilling tapered holes on the CGFRPP substrate before molding, which facilitated better interlocking with the injection molded SGFPP composite. The overmolding of preheated composites with tapered holes yielded up to 60% improvement in bonding strength. In general, having multiple holes helped improve bonding up to certain hole diameter. Similarly, preheating of the substrate over a short time improved the interfacial adhesion, while extended preheating resulted in a reduction of bonding quality. SEM analysis of the fracture surfaces after the tensile debonding test revealed that the SGFPP filled the holes on the substrate during overmolding.

MICRO-LEAKAGE OF PREHEATED COMPOSITE AS A CEMENTATION MATERIAL IN INDIRECT ADHESIVE RESTORATION (LITERATURE REVIEW)

Introduction: Composite resin is a material that is often used to perform dental restorations, but it can cause a deficiency called polymerization shrinkage which can be overcome by preheating the composite material. In several studies, there are differences of opinion regarding using preheating techniques at 60oC to overcome polymerization shrinkage. Review: This article intends to analyze the level of microleakage on the restoration of adhesive indirectly as cementing materials with preheated composites. A total of 49 journals from PubMed, NCBI, BMC, Research gate, Z-library, EBSCO, Google Scholar, and other international journal websites were analyzed. Conclusion: The preheating method showed samples with heating of 60oC had statistically lower microleakage at cervical margins. However, preheating resulted in an increase in the contraction voltage of undesirable polymerization.

Effect of ultrasound on preheated resin composites used as ceramic luting agents

This study investigated the effect of ultrasound application when luting ceramic using two preheated composites that show distinct responses to preheating at 69°C: Filtek Z100 and Z350XT. RelyX Veneer was the control. Feldspar disks were luted using the resin-based luting agents (RBLAs), and ultrasound was tested. Biaxial flexure strength (σbf) was calculated at z-axial positions of the luted disks (z=0; z=-t2). Microtensile bond strength (μTBS) to ceramic was tested (n=30). Data were analyzed at α=0.05. At z=0, the σbf was higher for Z350 when ultrasound was not used. When ultrasound was applied, the σbf was similar between Z350 and Z100. At z=-t2, differences across the RBLAs were observed: Z350 was superior than Z100 and control without ultrasound. Ultrasound increased σbf for Z100 at both axial positions. The preheated composites yielded higher μTBS than the control. Ultrasonication increased the mechanical performance of ceramic luted with Z100 without influencing the film thickness.

Temperature change of the pulpal floor and restoration with preheated bis-GMA free and containing resin composite (a randomized clinical trial)

BackgroundPreheating is one of several innovative approaches and improvements developed to increase the durability and clinical behavior of resin composites. Development of preheated composites is to reduce its viscosity in order to improve resin composite adaptation and placement ease. The purpose of this clinical trial was to study the effect of preheating Bis-GMA free and Bis-GMA-containing resin composites at different temperatures on the pulpal floor and restoration temperature. A total of twenty individuals (N = 40) have two carious posterior teeth that need to be restored were randomly assigned to one of two groups based on the type of restorative materials used: (group 1) Bis-GMA-containing resin composite VisCalor bulk (VCB), and (group 2) Bis-GMA-free resin composite Admira Fusion x-tra (AFX). Preheating temperatures of 50 °C and 70 °C were utilized to separate each group into two subgroups. Class I or II cavities were prepared. Thermometer device with two separate K-type temperature probes was used to measure the base line temperature values at the pulpal floor before beginning the restorative procedure (C0), pulpal floor during packing of preheated composite (C1), the top composite surface after packing and before curing (C2), pulpal floor after curing of the preheated composite (C3), and top composite surface after curing (C4). One-way ANOVA and the Kruskal–Wallis test were used to analyze the data.ResultsThe measured temperature of pulpal floor for both preheated VCB or AFX at 50 °C or 70 °C revealed significant increasing from base line measured temperature to during packing as well as after curing with (P-value < 0.001). There was no significant difference for mean composite surface temperature for both preheated materials at 50 °C or 70 °C whether before or after curing.ConclusionsPreheating of bulk fill Bis-GMA free and containing resin composite rises both the pulpal floor and the restoration temperature; meanwhile, the rise in temperature was limited. The application of the curing unit caused the greatest temperature rise.

Effects of Rinsing Water Temperature and Preheated Composites on Microleakage of Composite Restorations with Two Bonding Agents.

Objectives: The aim of this study was to evaluate the effects of rinsing water temperature and preheated composites on microleakage of class V restorations with two different bonding agents. Materials and Methods: Eighty class V cavities were prepared in the buccal and lingual surfaces of 40 molars. Single Bond and Prime and Bond NT bonding agents were used. The teeth were divided into four groups of 10. G1: After acid etching, cavities were rinsed with 23˚C water and filled with 23˚C composite resin. G2: Rinsing water and composite resin had 55˚C temperature. G3: Rinsing water had 55˚C and composite resin had 23˚C temperature. G4: Rinsing water had 23˚C and composite resin had 55˚C temperature. The specimens were immersed in 0.5% basic fuchsine dye. Microleakage scores were analysed with the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests. Results: There were significant differences in microleakage of specimens prepared with Single Bond and Prime and Bond NT only in group 1 (P<0.05). There were no significant differences between the microleakage of groups rinsed with different water temperatures (P>0.05). There were significant differences between the unheated and preheated composite groups (P<0.05). Conclusion: Preheating of composite is a valuable method to increase its adaptability and decrease microleakage of composite restorations.

One-year clinical evaluation of bulk-fill composite resin restorations plasticized by preheating and ultrasonics: A randomized clinical trial.

Introduction:Bulk-fill composite restorations displayed substantial annual failure related to imperfect marginal adaptation. Although preheated composites improved, marginal adaptation demonstrated early loss of plasticity. A new technique of ultrasonics plasticization was used for fabricating restorations.Aim:The aim of this study was to assess the clinical behavior of bulk-fill composite resin restorations plasticized by preheating and ultrasonics.Methodology:Randomized split-mouth double-blinded clinical trial was designed. Bulk-fill composite resin (Tetric N-Ceram Bulk Fill Ivoclar Vivadent products, Delhi) was used to fill 56 cavities. In 28 restorations, composite resin was plasticized by preheating in composite warmer (Delta Co., India) and remaining were plasticized with modified ultrasonic–retreatment tip-RT No 2 (Cricdental, India). Clinical follow-up assessments were done at 6 and 12 months using Ryge's criteria. Mann–Whitney U-test was used for statistical analysis with P < 0.05 and effect size of 0.61.Results:Hundred percent clinical success with ultrasonic plasticized group and 95.2% success with preheated composite resin group were observed without statistical significance.Conclusion:The ultrasonics plasticization of composite resin demonstrated comparable results with that of preheated composite resin after 6- and 12-month recall. Use of vibration energy utilizing the thixotropic effect might have resulted in better clinical performance.

36-Month Randomized Clinical Trial Evaluation of Preheated and Room Temperature Resin Composite.

This study evaluated the effect of preheating resin composites (RCs) on the clinical performance of class I restorations during a 36-month period using a split-mouth, double-blinded randomized design. A total of 35 patients were selected. Every patient received one pair of class I nanofilled resin composite (RC, Filtek Z350 XT) posterior restorations (n=70). One side of the mouth received preheated composites; on the other side, the composite was placed in a nonheated state following the manufacturer's instructions. These restorations were evaluated at 1-week (baseline), 12-months, 24-months, and 36-months using the FDI World Dental Federation criteria. The statistical analyses were also performed using the Wilcoxon and Friedman tests with the level of significance set at 0.05. After 36 months, 33 patients attended the recall visits, and 66 restorations were evaluated. The Friedman and Wilcoxon signed-rank tests revealed insignificant differences between both groups (p>0.05) for all FDI parameters. However, a significant difference was detected for staining as a criterion at 36 months (p=0.01). Moreover, a significant difference in the staining was detected when the baseline and 36 months were compared in the nonheated RC group (p=0.001). For esthetic, functional, and biological properties, the nonheated composite exhibited 93.9%, 100%, and 100% of the clinically accepted scores, respectively, and the preheated group presented 100% for all properties. Four restorations had postoperative sensitivity at baseline for nonheated (11.4%) and five for preheated (14.2%), but the postoperative sensitivity scores were considered highly acceptable at 12-, 24-, and 36-months. After 36 months, preheated nanofilled RCs showed an acceptable clinical performance similar to that of the nonheated ones in class I restorations, but with better resistance to marginal staining.

4 - Degree of Conversion of Resin-Based Luting Materials Containing Alternative Photoinitiators

Evaluate the degree of conversion (DC) of pre-heated composites, light- and dual-cured resin cements containing alternative photoinitiators under lithium disilicate ceramic with different thicknesses light cured using single-peak and dual-peak light curing units (LCUs). Thirty rectangular (12 ×14 mm; n= 5) lithium disilicate ceramic (IPS e.max CAD MT A2) specimens in six different thicknesses (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mm) were cut using a precision saw machine. The spectral irradiance (mW/cm 2 /nm) of a single-peak (SmartLite Pro Cure) and a dual-peak (SmartLite Pro Polycure) LCUs and the light transmittance through the ceramic with different thicknesses were evaluated using a spectrophotometer (MARC Light Collector). LCU beam profile was also evaluated (ZWO ASI). The DC of a pre-heated dental composite (TPT, Tetric Prime T using the CalSet at 68 C), a light-cured resin cement (VLC, Variolink LC) and a dual-cured resin cement (VDC, Variolink DC) was evaluated using FTIR spectroscopy. The luting agents were light cured with no ceramic interposed for 10 s and 40 s and through the ceramics with different thicknesses for 10 s using both LCUs. Statistical analyses were performed according to the different experimental designs with a level of significance of α= 0.05. The single-peak LCU emitted an irradiance of 1335 7 mW/cm2 with 98.4% of the irradiance within the blue spectrum. The dual-peak emitted an irradiance of 1192 4 mW/cm2 with 72.6% of the irradiance within the blue spectrum and 27.4% within the violet spectrum. The ceramic thickness has an exponential effect on the decrease of the light transmitted. VLC had a higher DC when using dual-peak and presented a maximum DC ratio above 80% up to 2 mm of ceramic thickness; VLC DC with single-peak LCU only cured efficiently up to 1 mm of ceramic thickness. There were no significant differences on the VDC DC when light cured with both LCUs at any thickness and VDC cured above the 80% of the maximum DC in all conditions, except for the single-peak LCU with a 3 mm thick ceramic. No differences were found for the TPT using both LCUs and TPT can be efficiently cured through a ceramic with up to 1 mm thickness. Dual-peak LCUs were more efficient than single-peak on curing light- and dual-cured resin cements containing alternative photoinitiators, but there is no difference on the DC of pre-heated composites light cured with single- or dual-peak LCUs.

Bond Strength Level of Preheated Composite Used as a Cement in Indirect Adhesive Restoration

Introduction: Heating composite resins can reduce viscosity properties, increase adaptation to cavity walls, and facilitate application. There is still a lot of debate about the degree of microleakage and bond strength in preheated composites to determine how strong these composites are as cementation materials. Purpose: To analyze the strength level of preheated composite as cementation material in indirect adhesive restoration in terms of microleakage rate and bond strength. Methods: Preheating composite can reduce the viscosity of the composite to facilitate the placement of the composite and obtain better adaptation to the cavity wall. By analyzing the relevant references, the strength of the preheated composite material will be investigated by looking at the level of microleakage and the level of bonding between surfaces. Conclusion: Heating the composite to an appropriate temperature (50°C) can reduce microleakage and increase the micro-shear bond strength in the exposed dentin.

Effect of Antiseptic Mouthwash as Water Substitute on Setting Time and Detail Reproduction of Alginate Impression Material

Introduction: Heating composite resins can reduce viscosity properties, increase adaptation to cavity walls, and facilitate application. There is still a lot of debate about the degree of microleakage and bond strength in preheated composites to determine how strong these composites are as cementation materials. Purpose: To analyze the strength level of preheated composite as cementation material in indirect adhesive restoration in terms of microleakage rate and bond strength. Methods: Preheating composite can reduce the viscosity of the composite to facilitate the placement of the composite and obtain better adaptation to the cavity wall. By analyzing the relevant references, the strength of the preheated composite material will be investigated by looking at the level of microleakage and the level of bonding between surfaces. Conclusion: Heating the composite to an appropriate temperature (50°C) can reduce microleakage and increase the micro-shear bond strength in the exposed dentin.

Preheated composite: Innovative approach for aesthetic restoration

Resin-based composites are today one of the most widely used restorative materials. However, its most debilitating problem is volumetric shrinkage due to polymerization which may result in contraction stress and subsequent micro leakage and adhesion failure. Preheating composites prior to polymerisation have several advantages over conventional composites. This review article highlights the mechanical properties, advantages and significance of preheated composites.