Four-year Outcomes of Class III and IV Anterior Restorations Based on a Subset of German Health Insurance Data.

PURPOSE: Numerous studies report on the outcome performance of posterior composite restorations. However, there are fewer studies providing data for anterior restorations. The aim of this study was to evaluate the clinical outcome performance of anterior permanent restorations by analyzing a large dataset from a German national health insurance company. MATERIALS AND METHODS: Routine claims data from a major German national health insurance company were assessed. Fee codes were used for tracing restoration careers on a day-count basis. The treatment was defined as a placed restoration (Class III and IV) on a mesial or distal tooth surface, irrespective of the extension. The restorations were placed between January 1, 2010 and December 31, 2013. Statistical analyses were conducted using Kaplan-Meier survival analysis to determine cumulative 4-year survival rates. The primary outcome was re-intervention on the same surface. Secondary outcomes were crowning and extraction which were analyzed separately. RESULTS: A total of 2,417,791 restorations involving mesial surfaces and a number of 2,409,031 restorations involving distal surfaces were observed. At 4 years, the cumulative survival rates concerning the primary outcome 're-intervention' were 79.9% for mesial and 80.9% for distal restorations. The respective annual failure rates (AFR) were 5.5% and 5.2%. Four-year survival rates for the secondary outcome 'crown' were 93.8% for mesial and 94.1% for distal anterior restorations. The respective AFRs were 1.6% and 1.5%. For the secondary outcome 'extraction,' the respective rates were 94.6% for mesial and 93.9% for distal restorations. The respective AFRs were 1.4% and 1.6%. CONCLUSION: The performance of permanent anterior restorations which were placed in general dental practices in Germany can be rated as acceptable.

Evaluation of Colour Changes in Nanocomposite-Based Bulk-Fill and Universal Composite Using Different Polishing Systems.

PURPOSE: Resins composites are widely used in modern dentistry because of their aesthetic and physical properties. However, discoloration of anterior tooth restorations is a common complaint. Understanding the factors affecting the colour stability of resin composites can lead to longer-lasting repairs. This study aimed to evaluate and compare the colour changes of nanocomposite-based bulk-fill and universal resin composites after immersion in coffee using various polishing systems. MATERIALS AND METHODS: A total of 160 samples were prepared using four different composite groups, with 40 pieces for each combined group. Based on the finishing procedure, the samples were divided into four subgroups for each composite group. Three different polishing procedures were applied to the samples according to the manufacturer's instructions. The control group was not subjected to any treatment. Initial colour measurements were performed using a VITA Easyshade V spectrophotometer. After the initial measurements, the samples were immersed in a Nescafe coffee solution for seven days, followed by colour measurements. Data were analysed using the Kolmogorov-Smirnov test and two-way analysis of variance. Tukey's honest significant difference (HSD) test was used to determine differences between subgroups. RESULTS: The results indicate that bulk-fill resins exhibit more discolouration than universal composites; however, this difference was not statistically significant. The resin group with the smallest discolouration was Ceram X, and the most effective polishing method was Twist polishing. CONCLUSION: Final surface polishing significantly reduced the composites' discolouration. These findings support the selection of appropriate materials and polishing techniques to achieve aesthetic outcomes and colour stability in dental restorations.

Effect of silver diamine fluoride application on the microtensile bond strength of three commonly used restorative materials in primary teeth: An ultrastructural study.

INTRODUCTION: Caries in primary teeth rapidly advances owing to its thin structure, thereby requiring restoration. However, restorations often fail due to various causes such as secondary caries and reduced microtensile bond strength (µTBS), which calls for the use of antimicrobial agents such as silver diamine fluoride (SDF). AIM: This study aims to measure and analyse the effect of SDF application on the µTBS of three regularly used restorative materials to dentin of primary teeth as well as compare the types of bond failure interfaces under SEM. MATERIALS AND METHODS: The study comprised 60 samples equally divided into six groups among three restorative materials, namely, glass ionomer cement (GIC, Groups I and II), resin-modified glass ionomer cement (RMGIC, Groups III and IV), and composite resin (Groups V and VI) with subdivisions of A and B, where A represented samples with SDF application and B represented samples without SDF application. RESULTS AND OBSERVATIONS: It was observed that µTBS of RMGIC to sound and carious dentin irrespective of SDF application was found to be statistically significant (P < 0.05), and when GIC, RMGIC, and composite resins were compared to both sound and carious dentin irrespective of SDF application, it was statistically significant (P < 0.05). SEM analysis revealed predominantly cohesive failures among all the groups. CONCLUSION: Based on the results, it was concluded that SDF has no adverse effect on the µTBS of GIC, RMGIC, and composite resin to both carious and sound dentin of primary teeth.

Bulk-flow composites in paediatric dentistry: long term survival of posterior restorations. A retrospective study.

Dental decay is a prevalent bacterial disease affecting a significant percentage of children globally. In paediatric dentistry, various materials are available for restoring deciduous teeth, addressing both functional and aesthetic concerns. However, paediatric dentists encounter challenges related to patient compliance, limited working time, and material handling. This study aims to observe the survival rate of bulk-fill composite restorations in paediatric patients over a five-year follow-up. A total of 198 patients aged 0 to 12 years underwent 673 class II restorations on deciduous first molars (1M) and second molars (2M). All restorations were conducted performed by 1 Pediatric DDS resident students from the Paediatric Dentistry Department (Padova University), utilizing using different isolation techniques. Bulk-fill composite restorations were evaluated over a five-year follow-up, and data were collected by a single investigator. After five years, 177 patients and 611 restorations were assessed. The retention rate was higher in primary second molars than in first molars, with fewer marginal dyschromies and less formation of secondary caries. The overall failure rate was higher in primary first molars and primary lower second molars. Bulk-fill composites demonstrated significantly positive performance in terms of retention, maintenance, and marginal dyschromies. Bulk-fill composites are promising materials of choice in paediatric dentistry due to their easy handling and favorable properties. Further research is necessary to compare high and low viscosity bulk-fill composites and assess the impact of different variables on restoration success.

Clinical evaluation of hydrophilic and hydrophobic resin-based sealants in uncooperative children: a randomized controlled clinical trial.

This clinical trial aimed to evaluate and compare the retention and cariostatic effects of hydrophilic and hydrophobic resin-based sealants (RBSs) for sealing pits and fissures in the permanent molars of uncooperative children. A split-mouth and double-blind randomized clinical trial (RCT) was conducted among 6- to 9-year-old uncooperative children. One hundred and four sound mandibular and maxillary first permanent molars were randomly allocated to be sealed with group I (UltraSeal XT® hydro™) or group II (Helioseal-F) in 34 uncooperative children. Clinical evaluation was performed by two investigators using the Color, Coverage and Caries system to assess sealant retention and cariostatic effect at 3-, 6- and 12-month intervals. Data analysis was performed using Friedman's and Mann-Whitney U tests. The final analysis included 31 children with 49 pairs of teeth. No significant differences were observed between the retention and cariostatic effects of hydrophilic and hydrophobic RBSs at the 3-, 6- and 12-month intervals (p = 0.23, p = 0.638, and p = 0.706, respectively) (p = 0.175, p = 0.065, and p = 0.171, respectively). After 12 months of follow-up, the hydrophilic RBSs showed an outcome equivalent to that of conventional hydrophobic RBSs in terms of retention and cariostatic effects. Therefore, hydrophilic RBSs could be considered as the sealing material of choice when isolation is difficult, particularly in uncooperative children.

Management of oblique root fracture in the middle third of two maxillary immature central incisors with severe caries in mixed dentitions: a case report.

Mid-root fractures are rare injuries in young permanent teeth and tend to have poor prognoses. This study presents a case of oblique root fracture of both maxillary immature central incisors in the middle third accompanied by delayed dental visit and severe caries of all primary teeth. After restoring all the primary and permanent teeth that needed stabilization, the coronal fragments were repositioned and stabilized with a flexible splint consisting of orthodontic wire and composite resin. A comprehensive and sequential dental treatment for other oral diseases and oral hygiene instructions were provided. A 16-month follow-up revealed that the two injured young permanent incisors were healed, surrounded by hard tissues and continued to grow both in length of the root and thickness of the root canal wall, with significant improvement in oral hygiene. Based on the outcome of this case, initial stabilization without endodontic therapy could be considered a successful treatment modality for young permanent teeth with oblique root fracture due to the growth of fractured teeth with vital pulp and the maintenance of natural dentition.

Spot-etch technique and other adhesive strategies for provisional veneers.

AIM: The objective of the present study was to evaluate the influence of different adhesive strategies regarding shear bond strength (SBS) of provisional resin--based materials bonded to the enamel surface as well as on the enamel surface roughness. MATERIALS AND METHODS: Bovine incisors were randomly divided into six groups (n = 10) according to the adhesive strategy used: BRControl (bis-acrylic resin); Spot-etch+BR (spot-etch + bis-acrylic resin); Spot--etchSB2+BR (spot-etch + adhesive + bis-acrylic resin); Spot-etchZ350Flow+BR (spot-etch + flowable composite resin + bis-acrylic resin); SBU+BR (universal adhesive + bis-acrylic resin); Spot-etchSBMP+Z350 (spot-etch + adhesive + composite resin). The enamel surface roughness was determined by a surface profil-ometer. An SBS test was performed in a universal testing machine, and failure modes were classified under magnification. The SBS data were analyzed by one-way analysis of variance (ANOVA). A paired t test was used for enamel surface roughness intragroup comparisons, and the Friedman one-way repeated meas-ures analysis of variance by ranks was used for differences in enamel surface roughness between groups, with the Tukey post hoc test (a = 0.05). RESULTS: BRControl had the lowest SBS values (MPa), with a significant difference (P ≤ 0.001) from the other groups. Spot-etch+BR had the highest SBS values but with no significant differences from the other groups in which the spot-etch technique was also used. Adhesive failure mode was predominant for all groups. BRControl had the lowest surface roughness difference, significantly different (P = 0.001) from all the other groups. CONCLUSIONS: Spot-etch and other adhesive strategies could be applied to increase the SBS values of provisional restorations to enamel compared with no surface pretreatment. However, the adhesive strategy may change the enamel surface roughness, revealing the importance of cleaning the tooth surface.

Evaluation of polymerization shrinkage stress and cuspal strain in natural and typodont teeth.

To evaluate the polymerization shrinkage stress and cuspal strain (CS) generated in an artificial (typodont) and in a natural tooth using different resin composites. Twenty artificial and 20 extracted natural molars were selected. Each tooth was prepared with a 4x4 mm MOD cavity. The natural and typodont teeth were divided into four experimental groups (n=10), according to the resin composite used: Filtek Z100 (3M Oral Care) and Beautifil II LS (Shofu Dental). The cavities were filled using two horizontal increments and the CS (µS) was measured by the strain gauge method. Samples were sectioned into stick-shaped specimens and the bond strength (BS) (MPa) was evaluated using a microtensile BS test. Shrinkage stress and CS were analyzed using 3D finite element analysis. No difference was found between the type of teeth for the CS as shown by the pooled averages: Natural tooth: 541.2 A; Typodont model: 591.4 A. Filtek Z100 CS values were higher than those obtained for Beautifil II LS, regardless of the type of teeth. No statistical difference was found for the BS data. Adhesive failures were more prevalent (79.9%). High shrinkage stress values were observed for Filtek Z100 resin, regardless of tooth type. The CS of typodont teeth showed a shrinkage stress effect, generated during restoration, equivalent to that of natural teeth.

Antibacterial properties of mesoporous silica coated with cerium oxide nanoparticles in dental resin composite.

Cerium oxide nanoparticles are known for their antibacterial effects resulting from Ce3+ to Ce4+ conversion. Application of such cerium oxide nanoparticles in dentistry has been previously considered but limited due to deterioration of mechanical properties. Hence, this study aimed to examine mesoporous silica (MCM-41) coated with cerium oxide nanoparticles and evaluate the antibacterial effects and mechanical properties when applied to dental composite resin. Cerium oxide nanoparticles were coated on the MCM-41 surface using the sol-gel method by adding cerium oxide nanoparticle precursor to the MCM-41 dispersion. The samples were tested for antibacterial activity against Streptococcus mutans via CFU and MTT assays. The mechanical properties were assessed by flexural strength and depth of cure according to ISO 4049. Data were analyzed using a t-test, one-way ANOVA, and Tukey's post-hoc test (p = 0.05). The experimental group showed significantly increased antibacterial properties compared to the control groups (p < 0.005). The flexural strength exhibited a decreasing trend as the amount of cerium oxide nanoparticle-coated MCM-41 increased. However, the flexural strength and depth of cure values of the silane group met the ISO 4049 standard. Antibacterial properties increased with increasing amounts of cerium oxide nanoparticles. Although the mechanical properties decreased, silane treatment overcame this drawback. Hence, the cerium oxide nanoparticles coated on MCM-41 may be used for dental resin composite.

Using Bulk-Fill Composite and High-Intensity Curing When Light Tip Placement Is Compromised.

Purpose: To evaluate whether reduced curing performance due to compromised light tip placement can be mitigated by bulk-fill composite and/or high-intensity curing light. Methods: Plastic discs with 2.5-mm deep cavities were filled with a conventional (Mosaic™) or bulk-fill (Tetric® PowerFill) composite and cured with a BluePhase® PowerCure curing light at normal and high-power settings, with light tip placement at distance and/or 45 degree angle. Curing time and irradiance were three, five, or 10 seconds at 1,200, 2,000, or 3,000 mW/cm2 (10 samples). After 24 hours, Vickers hardness on top and bottom surfaces was measured and analyzed using analysis of variance and pairwise comparisons (α<0.05). Results: All top surfaces had higher hardness than bottom surfaces. Cure (bottom-to-top hardness ratio) was significantly affected by material, distance/angle, and curing regimen (P<0.001), and generally decreased when tip distance and angle increased. Bottom-to-top hardness ratios of bulk-fill composite (0.42 to 0.66) were significantly higher than those of conventional composite (0.20 to 0.31). High-power curing significantly increased bulk-fill's curing performance as it was specifically formulated for this curing light. Conclusions: Increased light tip distance and angle compromised composite curing. Bulk-fill composite cured better at the bottom of the restoration than conventional composite regardless of light tip distance/angle. High-power light curing improved curing performance only in bulk-fill composite. Nevertheless, due to low bottom-to-top ratios (0.20 to 0.66) across all samples, even under ideal light tip placement, both composites should be cured in increments of less than 2.5 mm.

Impact of Carbonated Beverages on Color Stability and Home Bleaching Efficacy of BulkFill Composite Resins.

Purpose: The purpose of this study was to assess, in vitro, the color stability and bleaching response of three bulk-fill composite resins-Activa™, Tetric®-N-Ceram Bulk-Fill, and Filtek™ One Bulk-Fill???and one conventional composite resin, Filtek™ Z250, after immersion in commonly consumed carbonated beverages and subsequent home bleaching with 15 percent carbamide peroxide. Methods: Ninety-six samples (two- and four-mm thick) of the materials were immersed in malt drink, energy drink, cola, or distilled water for one day, one week, and two months. After two months, samples underwent home bleaching with 15 percent carbamide peroxide gel. Spectrophotometric analysis measured color and whiteness changes pre-immersion, post-immersion, and post-bleaching. Statistical significance was determined using factorial mixed analysis of variance (ANOVA), three-way ANOVA, and Bonferroni post hoc tests (P<0.05). Results: All tested composite resins exhibited unacceptable discoloration (color change greater than 3.3) after two months in carbonated beverages. Filtek™ One Bulk-Fill and Filtek™ Z250 displayed the most significant discoloration, particularly when immersed in the malt drink (P<0.05). In contrast, Activa™ samples reached unacceptable discoloration within just one week in malt and cola drinks. Home bleaching yielded limited whiteness recovery, with Activa™ presenting acceptable whiteness post-bleaching after staining with cola and energy drinks. Conclusions: This study highlights the aesthetic risks of prolonged carbonated beverage consumption and the limitations of the assessed home bleaching technique using 15 percent carbamide peroxide. Enhanced dental education on the dietary effects of some beverages on restorative materials is indicated by these findings.

Comparative evaluation of retention, marginal adaptation and marginal discoloration of hydrophilic and hydrophobic pit and fissure sealants: A split-mouth randomized controlled trial.

BACKGROUND: Pit and fissure sealants are the most commonly used preventive measure against caries in permanent molars. Advancements in dental materials have led to the development of hydrophilic sealants. However, their clinical efficacy must be evaluated and compared with that of conventional hydrophobic sealants. OBJECTIVES: This study aimed to clinically evaluate and compare the retention, marginal adaptation and marginal discoloration of hydrophilic and hydrophobic pit and fissure sealants over a 12-month follow-up period. MATERIAL AND METHODS: The study was a split-mouth, double-blind, randomized controlled trial. A sample size calculation was performed, and 120 first permanent molars (60 in each group) were selected for inclusion in the study. According to the split-mouth design, the sample was randomly divided into 2 groups. Group A was treated with a hydrophilic sealant (UltraSeal® XT Hydro), while Group B was treated with a hydrophobic sealant (Conseal F). The sealants in both groups were applied in accordance with the manufacturer's instructions by a single operator. The sealants were evaluated clinically using visual and tactile methods by 2 independent examiners who were blinded to the procedure in accordance with the modified United States Public Health Service (USPHS) clinical rating system at placement and at 1, 3, 6, and 12 months. RESULTS: After 12 months of follow-up, the Conseal F sealant showed significantly better retention (p = 0.001), marginal adaptation (p = 0.023) and reduced marginal discoloration (p = 0.004) in comparison to the UltraSeal XT Hydro sealant. CONCLUSIONS: The Conseal F (hydrophobic) sealant demonstrated superior retention, marginal adaptation and marginal discoloration compared to the UltraSeal XT Hydro (hydrophilic) sealant.

Effect of mouthwashes on the color stability of a nanohybrid composite resin.

The aim of this study was to evaluate the influence of different mouthwash solutions on the color stability of a nanohybrid composite resin. Forty discs of Luna nanohybrid composite resin were prepared and randomly assigned to 4 experimental groups (n = 10), determined by the type of immersion solution: distilled water (DW); Oral-B Pro-Health mouthwash (OBPH); Listerine Total Care mouthwash (LTC); or Colgate Plax Infinity mouthwash (CPI). The discs were immersed in solution for 30 minutes a day and stored at 37°C for 24 hours. Digital photographs of each specimen were taken at each timepoint and transferred to a computer program for color analysis. The International Commission on Illumination L*a*b* system was used to analyze the color of the specimens at baseline and the overall color change (ΔE*) at baseline, 30 days, 60 days, and 90 days. Two-way analysis of variance was used to evaluate the influence of solution and time on ΔE* values (α = 0.05). The t test was used as a post hoc test to compare the mean values between groups (α = 0.05). After 30 days, all groups showed small color change values compared with baseline (ΔE*1 < 1.0). However, after 60 days, the LTC and CPI groups showed greater color change (ΔE*2) than the other groups, and the difference was statistically significant (P < 0.05). After 90 days, all groups differed significantly compared with the control group (P < 0.05), and all mouthwash groups presented color change values that are considered clinically unacceptable (ΔE*3 > 3.0). The results of this in vitro study indicate that mouthwash solutions do not cause significant color changes in nanohybrid composite resin for a period of up to 30 days; however, longer periods (90 days) of exposure could make the restorative material esthetically unacceptable.

Restoration with a posterior CAD/CAM onlay after failure of a direct resin-based composite restoration: a case report.

A conservative approach to restoration assists in preserving the remaining tooth structure of extensively destroyed vital teeth. This case report describes a single-appointment chairside technique for placement of ceramic restorations in posterior teeth. A patient presented for treatment of her mandibular right first molar, which had a fractured resin-based composite restoration. Due to the presence of vital pulp, extent of the restoration, and presence of caries in the tooth, the following treatment plan was proposed: placement of a lithium disilicate glass-ceramic onlay fabricated with a computer-aided design/computer-aided manufacturing workflow. After the dentist removed the restoration and performed selective caries removal, structural analysis guided the reduction of the buccal cusps. Immediate dentin sealing was performed with a 2-step self-etching adhesive system, and a 1-mm-thick layer of flowable resin-based composite was placed as a resin coating. A digital impression was obtained, the onlay restoration was designed, and a lithium disilicate block was milled and subsequently crystallized. When the onlay was completed, the tooth preparation was sandblasted, selectively etched, and coated with a universal adhesive. The intaglio surface of the onlay was cleaned and primed, the onlay was bonded with dual-cure resin cement, and occlusal adjustments were completed. Follow-up examinations at 1 and 4 months revealed the clinical success of the case. From start to finish, it takes approximately 2.5 hours to produce a single-appointment chairside restoration. The technique used in this case offers a fast-paced workflow that is comfortable and practical for the patient and provides a predictable clinical outcome without the need for a temporary restoration.

Influence of radiant exposure and material shade on the degree of conversion and microhardness of a resin-based composite.

This in vitro study evaluated the influence of radiant exposure and material shade on the degree of conversion (DC) and microhardness of a resin-based composite (RBC). Sixty-four RBC specimens in shades A1E (enamel) and A4D (dentin) were light cured at a calibrated exitance of 1000 mW/cm2 for 5, 10, 15, or 20 seconds, resulting in radiant exposure levels of 5, 10, 15, or 20 J/cm2. The DC was determined using Fourier-transform infrared spectroscopy (n = 3 per shade per exposure level). The Knoop hardness number (KHN) was measured on the top and bottom surfaces of each specimen (n = 5 per shade per exposure level). Data were analyzed using 2- and 3-way analyses of variance and post hoc Tukey tests (α = 0.05). The RBC shade did not affect the DC (P = 0.860), and the lowest DC values were achieved with an exposure level of 5 J/cm2 (P < 0.001). The shade did not affect the KHN on the top surface, but the radiant exposure level did, with the application of 5 J/cm2 resulting in significantly lower values (P < 0.05). For the bottom surface, shade A1E showed significantly higher KHN values than A4D (P < 0.001). An increase in the radiant exposure led to increased DC and KHN for both shades of RBC until reaching a saturation point of 10 J/cm2 for A1E and the top surface of A4D. The darker and more opaque shade was not adequately polymerized at a 2-mm depth, even when the highest radiant exposure level was applied.

Comparison of various methods of restoring adhesion to recently bleached enamel.

AIM: This study compared the effectiveness of several techniques in restoring compromised bonding to recently bleached enamel. METHODS: Seventy-five healthy bovine incisors were divided into five groups (n = 15). Fifteen teeth (Group 1) remained intact, whereas 60 (Groups 2 to 5) underwent at-home bleaching with 16% carbamide peroxide. The bonding procedures were as follows: Group 1: Bonding of resin composite to unbleached enamel; Group 2: Bonding immediately after bleaching; Group 3: Application of a 10% sodium ascorbate solution for 10 min before bonding; Group 4: Enamel removal to the depth of 0.5 mm; and Group 5: Increased curing time of the bonding agent to 80 instead of 20 s. After 24 h, the specimens were subjected to micro-shear testing, and the failure mode was determined. RESULTS: ANOVA revealed a significant difference in bond strength among the groups (P < 0.001). The mean bond strength was significantly lower in group 2 than in other groups (P < 0.05), which showed comparable bond strength to each other (P > 0.05). Adhesive failure was the most predominant failure type in all groups. The mixed failure occurred with a frequency of 26.7% in groups 3 and 5. The Fisher's exact test revealed a significant difference in failure modes among the groups (P = 0.047). CONCLUSIONS: The three experimental procedures used in this study, including the application of 10% sodium ascorbate before bonding, enamel removal to the depth of 0.5 mm, and increasing the curing time of the bonding agent to 80 s, were effective in restoring the compromised bonding to recently bleached enamel.

Comparison of the clinical performance of self-adhering flowable composite and resin-based pit and fissure sealant: a randomized clinical trial in pediatric patients.

BACKGROUND: Self-adhering flowable composites are an innovative step in reducing the chair time of pit and fissure sealant treatment. This study aimed to compare the clinical performance of self-adhering flowable composite (SELF-ADH) and resin-based pit and fissure sealant (RBs). METHODS: This is a double-blinded, randomized, split-mouth clinical trial conducted on 80 fully erupted permanent mandibular first molars from 40 children aged 6 to 12 years. For each participant, two permanent molars were randomly treated with SELF-ADH or RB. All sealants were assessed at 3, 6, and 12-month follow-ups considering retention, marginal integrity, marginal discolouration, colour matching, surface texture, and caries recurrence. To analyse the data, logistic regression and Fisher's exact tests were used (significance level P < 0.05). RESULTS: At the 12-month follow-up, the number of fully retained sealants in the SELF-ADH group was significantly higher than that in the RB group (P < 0.001). Also, The success rate of marginal integrity in the SELF-ADH group was significantly greater than the the RB group (P = 0.031), while the rate of sealant marginal discolouration was higher in the RB group (P < 0.001). The incidence of recurrent caries in teeth with partial loss of sealant in both groups (P = 0.004, P < 0.001) increased significantly over time. CONCLUSION: The retention and marginal integrity of the self-adhering flowable composite were significantly greater than those of the resin-based sealant. Therefore, due to the small number of work steps, flowable self-adhering composites can be used as alternatives to resin-based pit and fissure sealants. TRIAL REGISTRATION: This study was approved by the Ethics Committee of Kerman University of Medical Sciences with the code IR.KMU.REC.1399.556 and Iraninan Registry of Clinical Trials (IRCT) code IRCT20180521039763N4, as well as full compliance with the Declaration of Helsinki.

Surface roughness of different types of resin composites after artificial aging procedures: an in vitro study.

BACKGROUND: The temperature changes, chemical agents, and brushing activity that resin composite restorations are exposed to in the oral environment can cause changes in surface roughness. In this study, the aim was to investigate in vitro the clinical one-year surface roughness changes of different types of composites (flowable or conventional) from the same companies by subjecting them to immersion in solutions, brushing, and thermal cycling procedures to simulate intraoral conditions. METHODS: Four different resin composite brands were included in the study using both their conventional (Charisma Smart, 3M Filtek Ultimate Universal, Omnichroma, Beautifil II) and flowable resin composites (Charisma Flow, 3M Filtek Ultimate Flowable, Omnichroma Flow, Beautifil Flow Plus F00), giving 4 groups with 2 types of resin composite in each. 40 samples were prepared for each group/resin type, for a total of 320 samples. After initial surface roughness measurements by a mechanical profilometer, the samples were divided into 4 subgroups (n = 10) and immersed in solutions (distilled water, tea, coffee, or wine) for 12 days. The samples were then subjected to 10,000 cycles of brushing simulation and 10,000 cycles of thermal aging. Surface roughness measurements were repeated after the procedures. For statistical analysis, the 3-way analysis of variance and the Tukey test were used (p < 0.05). RESULTS: It was concluded that composite groups and types had an effect on surface roughness at time t0 (p < 0.001). At time t1, the highest surface roughness value was obtained in the Beautifil-conventional interaction. When the surface roughness values between time t0 and t1 were compared, an increase was observed in the Beautifil II and Beautifil Flow Plus F00, while a decrease was observed in the other composite groups. CONCLUSION: Composite groups, types, and solutions had an effect on the surface roughness of resin composites. After aging procedures, it was concluded that the Beautifil group could not maintain the surface structure as it exceeded the threshold value of 0.2 µm for bacterial adhesion.

Developing an optimised method for accurate wear testing of dental materials using the 'Rub&Roll' device.

Dental materials are challenged by wear processes in the oral environment and should be evaluated in laboratory tests prior to clinical use. Many laboratory wear-testing devices are high-cost investments and not available for cross-centre comparisons. The 'Rub&Roll' wear machine enables controlled application of force, chemical and mechanical loading, but the initial design was not able to test against rigid antagonist materials. The current study aimed to probe the sensitivity of a new 'Rub&Roll' set-up by evaluating the effect of force and test solution parameters (deionized water; water + abrasive medium; acid + abrasive medium) on the wear behaviour of direct and indirect dental resin-based composites (RBCs) compared with human molars against 3D-printed rod antagonists. Molars exhibited greater height loss than RBCs in all test groups, with the largest differences recorded with acidic solutions. Direct RBCs showed significantly greater wear than indirect RBCs in the groups containing abrasive media. The acidic + abrasive medium did not result in increased wear of RBC materials. The developed method using the 'Rub&Roll' wear machine in the current investigation has provided a sensitive wear test method to allow initial screening of resin-based composite materials compared with extracted human molars under the influence of different mechanical and erosive challenges.

Restoration-repair potential of resin-modified glass ionomer cement.

This in vitro study aimed to evaluate the repair bond strength of resin-modified glass ionomer cement using either the same material or a universal adhesive in the etch-and-rinse and self-etch modes plus resin composite. Twenty-four resin-modified glass ionomer cement blocks were stored in distilled water for 14 d and thermocycled. Sandpaper ground specimens were randomly assigned to three experimental groups according to the repair protocol: resin-modified glass ionomer cement (Riva Light Cure, SDI) and universal adhesive (Scotchbond Universal Adhesive, 3M Oral Care) in etch-and-rinse or self-etch modes and nanohybrid resin composite (Z350 XT, 3M Oral Care). After 24 h of water storage, the blocks were sectioned, and bonded sticks were subjected to the microtensile bond strength (µTBS) test. One-way ANOVA and Tukey's test were used to analyze the data. The failure mode was descriptively analyzed. The highest µTBS values were obtained when the resin-modified glass ionomer cement was repaired using the same material (p < 0.01). In addition, the mode of application of the universal adhesive system did not influence the repair bond strength of the resin-modified glass ionomer cement. Adhesive/mixed failures prevailed in all groups. Repair of resin-modified glass ionomers with the same material appears to be the preferred option to improve bond strength.