Impact of antibacterial composite resin on salivary pH dynamics in high-caries-risk children: An ex-vivo study.

Effect of composite resin containing antibacterial filler on sugar-induced pH drop caused by whole saliva bacteria

Direct composite resin fillings versus amalgam fillings for permanent posterior teeth.

The use of resin composites (RC) for complex restorations, including those involving cusp coverage, has increased dramatically in recent years. However, reports in the literature regarding the performance of posterior multisurface RC and amalgam (AM) restorations show conflicting results. This systematic review and meta-analysis aims to assess the clinical performance of complex (involving two or more surfaces) direct posterior resin composite and amalgam restorations in permanent teeth. Inclusion criteria were for prospective randomized controlled trials (RCTs) of multisurface direct RC and AM restorations of permanent posterior teeth with a follow-up period of three years or more. The trials needed to include a minimum of 20 restored teeth for each evaluated material. Retrospective studies, studies lacking survival rates or clearly reported reasons for failure, and those with unclear randomization methods were excluded. Five bibliographic databases (Medline-OVID, Embase, Cochrane Library, Web of Science, and LILACS [Latin American and Caribbean Health Sciences Literature Database]) and manual searches were screened. The Cochrane Risk of Bias Tool was used to assess the included studies. Random-effects meta-analyses were conducted using the Freeman-Tukey double arcsine transformation and the DerSimonian-Laird random-effects model to evaluate restorative failures and compare the survival of AM and RC restorations. From the 6303 identified studies, 198 underwent meticulous examination, and 15 RCTs met the inclusion criteria. Only two studies compared AM and RC restorations. Although the combined data from these studies showed a trend toward higher failure rates in multisurface RC restorations, the difference was not statistically significant (p=0.06). The most common reasons for the failure of RC restorations were secondary caries, restoration fracture, and tooth fracture. For AM, the most common reasons for failure were secondary caries and tooth fracture. The quality of the evidence was low. The scarcity of studies comparing RC and AM in complex restorations has resulted in insufficient evidence to substantiate superior performance by either material.

Background Resin-based composites are widely used in dental clinics because of their superior esthetics, preferable mechanical properties, and safety concerns. As a result, composite resin has replaced dental amalgam and glass ionomer restorations. Recurrent caries and fractures are the main reasons for the failure of resin composite restorations. Recurrent caries correlates to skills in cavity design, material selection and insertion. Material-related factors are significant due to microleakage. Promising technologies promote resin composites with antibacterial potential. Microleakage could result from polymerization shrinkage stress of the composite resins; the stress overcomes the bond strength of restoration, causing the passage of fluids and bacterial infiltration between walls of the cavity and filling material; it is also one of the withdrawals that impair the success of composite resin fillings. Oral biofilm harbors many bacteria that are involved in the development of secondary caries and demineralization of marginal enamel and dentin, resulting in dental plaque that is formed on teeth as well as on restorations, and growth of many bacteria such as Streptococcus mutans, bacterial adhesion and their growth on the surface of composite resins and other dental restorative materials is an essential parameter in the etiology of secondary caries formation. To overcome this problem, many researchers have focused on preparing new restorative materials that possess antibacterial activity. Therefore, this study was undertaken to formulate a novel antibacterial nanocomposite resin. Aim This study was conducted for synthesis and evaluation of a novel nanocomposite resin restorative material with different percentages of 1, 2, and 3% of nano quaternized poly (glycidyl methacrylate-co-2-hydroxy ethyl methacrylate; GMA-co-2-HEMA) tributyl phosphonium (Bu3P) on the antibacterial activity, and some mechanical properties. Materials and methods Nano quaternized poly (GMA-co-2-HEMA) Bu3P was formulated firstly, then the resin matrix of composite resin was prepared by mixing Bis-GMA, urethane dimethacrylate, and Bis-EMA as monomers. Triethylene glycol dimethacrylate and polyethylene glycol dimethacrylate as diluent comonomers to form the polymeric resin matrix. Photoinitiator (camphorquinone) and co-initiator (4EDMAB) were added. Silanized zirconia and silica nanoparticles and nanoclusters were mixed and were added to form composite resin nanofillers content, then the mixture was divided into four groups (n = 32) group I (control group, n = 8), and three experimental composite resin groups according to the added percentage of the synthesized copolymer: group II (1%, n = 8), group III (2%, n = 8), and group IV (3%, n = 8). Each group of composite resin was prepared in proportion with 72%wt filler 27%wt polymeric resin matrix, and 1% activation system. Antibacterial activity was assessed against S. mutans by broth dilution method according to ASTM E2149-13a standard, flexural strength according to ISO 4049:2009 by three-point bending test, and surface microhardness according to ASTM E-384:1999 criteria. Results The tested copolymer was successfully synthesized, and was evaluated by scanning electron microscope that showed rough surface and nanosized particles, Fourier transform infrared spectroscopy, and thermal gravimetric analysis. Specimens of group IV (3% of the tested copolymer) showed the best antibacterial activity which increased by 96%, enhanced flexural strength, and higher microhardness compared to the control group. Conclusions Quaternized nano poly (GMA-co-2-HEMA) Bu3P can be used in dental restorative materials; as its promising antibacterial effect, may be effective in secondary caries inhibition around composite resin restorations, and 3% of the tested copolymer is the best percentage to add.

The aim of this retrospective study was to investigate the clinical performance of posterior complex resin composite (RC) and amalgam (AM) restorations after a five-year period. One hundred and nineteen complex Class II restorations placed by dental students were evaluated using the USPHS criteria. Data were analyzed using Chi-square, Mann-Whitney, and Wilcoxon tests at a 0.05 level of significance. After five years, the percentages of clinically satisfactory complex Class II RC and AM restorations were 78% and 76.8%, respectively. The main reasons for the failure of AM restorations included secondary caries (Bravo-10.1%), defective marginal adaptation (Charlie-8.7%), and fracture of the tooth (Bravo-7.2%). RC restorations presented failures related to the fracture of the restoration (Bravo-16%) and defective marginal adaptation (Charlie-8.2%). There was a significantly higher incidence of secondary caries for AM restorations (AM-10.1%; RC-0%; p = 0.0415) and a higher number of fractures for RC restorations (AM-4.3%; RC-16%; p = 0.05). Regarding anatomy, AM restorations presented a significantly higher number of Alfa scores (49.3%) compared to RC restorations (22.4%) (p = 0.0005). The results of the current study indicate that complex class II RC and AM restorations show a similar five year clinical performance.

Beauty standards in today's modernized world scenario are formed by well-aligned and well-designed bright white teeth. One of the major reasons behind patients reporting to dental clinics is pain. Caries in the anterior primary teeth forms one of the major concerns from a restorative point of view. Very few studies are quoted in literature which stresses on the follow-up of anterior restorations in primary teeth. Hence, we evaluated and compared the efficacy of composite resin and resin-modified glass ionomer cement (RGIC) for class III restorations in primary anterior teeth. The present study was conducted in the pediatric dental wing and included a total of 80 patients aged 3 to 5½ years who reported with the chief complaint of carious lesions in the primary anterior teeth. Patients having minimal of a pair of similar appearing small carious lesions on the same proximal surfaces of the deciduous maxillary incisors were included for the study. All the patients were randomly divided into two groups: One in which RGIC restoration was done and other in which composite restoration was done. Cavity preparation was done and filling of the cavity with the restorative materials was carried out. Assessment of the restorations was done at 4, 8, and 12 months time following criteria given by Ryge et al. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Mann-Whitney test and one-way analysis of variance (ANOVA) were used to evaluate the level of significance; p value less than 0.05 was considered as significant. For composite and RGIC restorations, the mean score for anatomic shape was 1.21 and 1.10 respectively. While comparing the clinical parameters, nonsignificant results were obtained between composite and RGIC restorative materials at 4-, 8-, and 12-month interval. On comparing the clinical parameters for individual restorative materials at different time intervals, statistically significant results were obtained only for anatomical shape and form. Both RGIC and composite resin restorative materials showed acceptable clinical outcomes after 12 months of follow-up in deciduous anterior teeth. In restoring class III restorations in primary anterior teeth, both the restorative materials showed similar outcome. Keywords: Composite, Marginal, Resin-modified glass ionomer cement.

The aim of the present study was to evaluate the three-year clinical performance of a nanofilled resin composite, a packable resin composite, and silorane-based resin restorations in Class I occlusal cavities. Twenty-eight patients with at least three similar-sized occlusal lesions in molar teeth participated in the study. A total of 84 Class I occlusal restorations were placed: 28 with nanofilled resin composite (Filtek Supreme), 28 with packable resin composite (P60), and 28 with silorane-based resin (Filtek Silorane). Filtek Supreme and P60 were used with their respective etch-and-rinse adhesive system, Adper Single Bond 2, and Filtek Silorane was used with its respective self-etch adhesive, Filtek Silorane Adhesive. All restorations were placed by the same operator. The restorations were evaluated at baseline, at six months, and annually for three years according to modified US Public Health Service criteria by two calibrated examiners who did not know which restorative resin had been used. The three restorative materials for each category were compared using the χ (2) test at a significance level of 0.05. Cochran's Q test was used to compare the changes across the five time points for each restorative material. McNemar's test followed by Bonferroni adjustment was used when significance differences were found. At the end of the three years, 60 restorations were evaluated in 20 patients, with a recall rate of 71.4%. The retention rate was 100% for all restorative resins. Eight restorations from the P60 group, ten from the Filtek Supreme group, and nine from the Filtek Silorane group were rated Bravo for marginal discoloration. For marginal adaptation, three P60, five Filtek Supreme, and 11 Filtek Silorane restorations were rated Bravo. No statistically significant differences in overall clinical performance were found between the restorative materials except for marginal adaptation. P60 showed the best marginal adaptation at the end of the three years. No differences were observed between the restorative resins for any of the evaluation criteria tested (p>0.05). None of the restorations showed postoperative sensitivity, secondary caries, or loss of anatomic form. All restorative resins performed equally well in clinical conditions during the three-year evaluation, and no significant differences were found among them, except for marginal adaptation, in which P60 showed superior results.

The aim of this clinical study was to evaluate the clinical performance of Class II restorations of a high-viscosity glass ionomer material, of a bulk-fill composite resin, and of a microhybrid composite resin. One hundred nine Class II restorations were performed in 54 patients using three different restorative materials: Charisma Smart Composite (CSC; a conventional composite resin), Filtek Bulk Fill Posterior Restorative (FBF; a high-viscosity bulk-fill composite), and Equia Forte Fil (EF; a high-viscosity glass ionomer). Single Bond Universal adhesive (3M ESPE, Neuss, Germany) was used for both conventional and bulk-fill composite resin restorations. The restorations were evaluated using modified US Public Health Service criteria in terms of retention, color match, marginal discoloration, anatomic form, contact point, marginal adaptation, secondary caries, postoperative sensitivity, and surface texture. The data were analyzed using the chi-square, Fisher, and McNemar tests. Eighty-four restorations were evaluated at two-year recalls. There were clinically acceptable changes in composite resin restorations (FBF and CSC). In addition, no statistically significant difference was observed between the clinical performances of these materials in terms of all criteria (p>0.05). However, there was a statistically significant difference between the EF group and the FBF and CSC groups in all parameters except for marginal discoloration, secondary caries, and postoperative sensitivity (p<0.05). The tested bulk-fill and conventional composite resins showed acceptable clinical performance in Class II cavities. However, if EF is to be used for Class II restoration, its use should be carefully considered.

Composite resins are currently the most popular dental restorative materials worldwide. Composite resins provide certain advantages such as good esthetics, easy application, and lower costs. However, there remain some disadvantages to their use, such as polymerization shrinkage, low wear resistance, and marginal discoloration. Composite resins are composed of organic monomers and inorganic fillers. High molecular weight dimethacrylate monomers with low polymerization shrinkage and high strength, such as bisphenol A-glycidyl dimethacrylate (bis-GMA), are most commonly used. The high viscosity of bis-GMA reduces the loading of fillers and also the degree of conversion of the monomers in the absence of other low viscosity diluents. Low molecular weight diluent monomers, such as triethylene glycol dimethacrylate (TEGDMA), are often added to reduce viscosity and increase the reactivity and conversion rate. However, the diluent monomers also increase polymerization shrinkage, leading to polymerization stress, debonding at the restoration-tooth interface, secondary caries, postoperative sensitivity, pulpal irritation, and marginal discoloration. Polymerization shrinkage is the principal cause of failure of clinical dental composite resin fillings. Reducing this shrinkage, thus, represents one of the most important goals in the development of new matrices for composite resins. Currently, there remains a lack of “non-shrinkage” composite resins worldwide. In this study, we aimed to develop low-shrinkage composite resins for dental application. As expected, the higher the molecular weight and volume the monomer, the less extensive the shrinkage when polymerized. Most commercial dental composite resins are composed of bis-GMA or its derivatives. We increased the molecular weight and volume of the dimethacrylate molecule by conjugating functional side chains to the dimethacrylate structure. Urethane, which is a compound of diisocyanate and 2-hydroxyethyl methacrylate (HEMA), is a material suitable for use as a dimethacrylate side chain. Polyurethane displays certain advantages, such as low shrinkage, high wear resistance, and good biocompatibility. We selected three diisocyanates with different chemical structures as side chain materials: 1,6-Diisocyanatohezane (HDI), 4,4’-diisocyanatodicyclohexylmethane (H12MDI) and toluene 2,4-diisocyanate (TDI). HDI is a linear structure molecule. H12MDI contains two aliphatic rings (cyclohexane) linked by a methyl group, whereas TDI contains a toluene moiety. When conjugated to dimethacrylate, these three chemical structures reduced polymerization shrinkage and increased the mechanical strength of the composites. Different structures and numbers of side chains on dimethacrylate provided different results. The molecular weight and viscosity of experimental resins were increased as functional side chain density was increased. The polymerization shrinkage and degree of conversion were decreased when functional side chain density was increased. Polymerization shrinkage in the DM-M-1.5c and DM-T-1.5c groups was significantly less extensive than in the other groups (p<0.05). Although the degree of conversions of these two groups were significantly lower than that of the control group, the surface hardness values were equal to or significantly higher than that of the control group because of increasing functionalities of the side chain-modified groups. There were non-significant differences between these two groups and the control group in cell vitality. The biocompatibility of dental resin is related to the stereo hindrance of resin matrix molecular structures. When the ratio of HDI, H12MDI or TDI functional side chain to dimethacrylate is increased, the stereo hindrance of resin structure is increased, more toxic resin monomers are trapped in the complicated resin structure, and thus the resin matrix reveals less cytotoxicity. The urethane modification of dimethacrylate, therefore, represents an effective means of reducing polymerization shrinkage and increasing surface hardness. The modified dimethacrylate with good biocompatibility might be suitable for dental use in the future.

This systematic review was designed to compare the clinical effectiveness of high-viscosity glass ionomer cement (HVGIC) restorations to direct composite resin (CR) restorations in single- or multisurface cavities in primary teeth. Restorative procedures are typically used to treat caries in primary teeth. Due to their improved preservation of the natural tooth structure and their adhesion to the remaining tooth structure, CR and GIC have drawn attention as the preferred restorative materials. In the literature, over the past 20 years, the term HVGIC has developed. Compared to C-GICs, HVGICs appear to have a higher survival rate. However, isolated studies provide contradictory findings regarding the durability of restorations in primary teeth. Major electronic databases were thoroughly searched to find publications from the years 2000 to 2021. Studies included were randomized and nonrandomized clinical trials on children aged 3-13 years, in which restoration of primary teeth using HVGIC and CR was performed. This systematic review includes four studies [three randomized controlled trials (RCTs) and one nonrandomized controlled trial]. No statistically significant difference between these materials was seen in any of the included studies. This systematic review of findings supports the assertion that both HVGIC and CR restorations deliver satisfactory outcomes in terms of clinical efficacy and overall survivability. It was found that, for both materials, class I restorations had statistically higher survival rates than class II restorations. Long-term studies are essential to evaluate the clinical efficacy of both restorations. This systematic review outlines the application of HVGIC and CR as restorative materials for pediatric dentists to use in their everyday dental practices. Krishnakumar K, Kalaskar R, Kalaskar A, et al. Clinical Effectiveness of High-viscosity Glass Ionomer Cement and Composite Resin as a Restorative Material in Primary Teeth: A Systematic Review of Clinical Trials. Int J Clin Pediatr Dent 2024;17(2):221-228.

BackgroundSecondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. The diversity of the bacterial sources and the different types of filling materials could play a role in secondary caries. The aim of this study was to determine and compare the microbial spectrum of secondary caries biofilms around amalgam and composite resin restorations.MethodsClinical samples were collected from freshly extracted teeth diagnosed with clinical secondary caries. Samples were categorized into four groups according to the types of restoration materials and the classification of the cavity. Biofilms were harvested from the tooth-restoration interface using a dental explorer and after dilution were incubated on special agars. The bacteria were identified using the biochemical appraisal system. Statistical calculations were carried out using SPSS11.5 software to analyze the prevalence of the bacteria involved in secondary caries.ResultsSamples from a total of four groups were collected: two groups were collected from amalgam restorations, each had 21 samples from both Class I and Class II caries; and the other two groups were from composite resin restorations, each had 13 samples from both class I and class II caries. Our results showed: (1) Anaerobic species were dominant in both restoration materials. (2) In terms of the types of individual bacteria, no significant differences were found among the four groups according to the geometric mean of the detected bacteria (P > 0.05). However, there were significant differences among the detected bacteria within each group (P < 0.05). The composition of each bacterium had no statistical difference among the four groups (P > 0.05), but showed significant differences among the detected bacteria in each group (P < 0.05). (3) Among the four groups, there were no significant differences for the detection rate of each bacterium (P > 0.05), however, the detection rate of each bacterium within each group was statistically different among the detected bacteria (P < 0.05).ConclusionsThe proportion of obligatory anaerobic species was much greater than the facultative anaerobic species in the biofilm of secondary caries. Statistically, the materials of restoration and the location of secondary caries did not show any significant effects on the composition of the microflora.

Bulk-fill restorative materials such as bulk-fill composite resins and high viscous glass ionomer cements have become very popular materials in operative dentistry because their application is easy and time-saving.Objectives:The aim of this clinical study was to evaluate the clinical performance of a highly viscous reinforced glass ionomer material, a bulk-fill composite resin and a micro hybrid composite resin in Class II restorations.Methodology:In total, 109 Class II restorations were performed in 54 patients using three different restorative materials: Charisma Smart Composite (CSC); Filtek Bulk Fill Posterior Restorative (FBF); Equia Forte Fil (EF). Single Bond Universal adhesive (3M ESPE, Germany) was used with composite resin restorations. The restorations were evaluated using modified USPHS criteria in terms of retention, color match, marginal discoloration, anatomic form, contact point, marginal adaptation, secondary caries, postoperative sensitivity and surface texture. The data were analyzed using Chi-Square, Fischer's and McNemar's tests.Results:At the end of one year, 103 restorations were followed up. No changes were observed during the first 6 months. At the end of one year, there were small changes in composite restorations (FBF and CSC) but no statistically significant difference was observed between the clinical performances of these materials for all criteria (p>0.05). However, there was a statistically significant difference between EF, FBF and CSC groups in all parameters except marginal discoloration, secondary caries and postoperative sensitivity in one-year evaluation (p<0.05).Conclusion:Bulk-fill composite resins and conventional composite resins showed more successful clinical performance than highly viscous reinforced glass ionomers in Class II cavities.

The aim of the study was to investigate reasons for replacement and repair of posterior resin composite (RC) restorations placed in permanent teeth of children and adolescents attending Public Dental Health Service in Denmark. All posterior RC placed consecutively by 115 dentists over a period of 4 years were evaluated at baseline and up to 8 years later. The endpoint of each restoration was defined when repair or replacement was performed. The influence of patient, dentist and material factors on reasons for repair or replacement was investigated. A total of 4,355 restorations were placed. Replacements comprised 406 and repairs 125 restorations. The cumulative survival rate at 8 years was 84 %. Failed restorations were most frequently seen due to secondary caries (57 %), post-operative sensitivity (POS) (10 %) and RC fracture (6 %). POS was observed in 1.5 % of the evaluations and reported more often in girls and from teeth restored with a base material. Older dentists showed lower proportion of replaced restorations due to secondary caries than younger dentists. Posterior RC restorations in children and adolescents performed in general practice showed a good durability with annual failure rates of 2 %. The main reason for failure was secondary caries followed by post-operative sensitivity and resin composite fracture. A high proportion of replaced/repaired RC restorations were caused by primary caries in a non-filled surface. Secondary caries was the main reason for failure of RC in children and young adults. More teeth with post-operative sensitivity and a shorter longevity of restorations were observed when a base material was used.

Quality and Survival of Direct Light-Activated Composite Resin Restorations in Posterior Teeth: A 5- to 20-Year Retrospective Longitudinal Study.

To estimate the association between the restorative material used and time to further treatment across population cohorts with universal coverage for dental treatment. Cohort study of variation in survival time for tooth restorations over time and by restoration material used based on an Accelerated Failure Time model. Primary dental care clinics. Members of Canada's First Nations and Inuit population covered by the Non-Insured Health Benefits program of Health Canada for the period April 1, 1999 to March 31, 2012. Tooth restorations using resin composite or amalgam material. Survival time of restoration to further treatment. Median survival time for resin composite was 51 days longer than amalgam, for restorations placed in 1999-2000. This difference was not statistically significant (p⟩0.05). Median survival times were lower for females, older subjects. Those visiting the dentist annually, and decreased monotonically over time from 11.2 and 11.3 years for resin composite and amalgam restorations respectively placed in 1999-2000 to 6.9 and 7.0 years for those placed in 2009-10. Resin composite restorations performed no better than amalgams over the study period, but cost considerably more. With the combination of the overall decrease in survival times for both resin composite and amalgam restorations and the increase in use of resin composite, the costs of serving Health Canada's Non-Insured Health Benefits population will rise considerably, even without any increase in the incidence of caries.