Polyacid-modified Composite Resin Research Articles

The effect of fluoride varnish application on colour change due to paediatric drug usage in polyacid-modified composite resin: an in vitro study.

Colour stability is important in the long-term aesthetic success of restorative materials and is affected by both internal and external factors. Internal discolourations are due to the properties of the restorative materials. External discolourations can be associated with frequent consumption of food and beverages and the use of suspensions or syrups containing colourants/additives. Fluoride varnish application has an important place in preventive dentistry. The purpose of the research was to examine the protective effect of fluoride varnish application on the colour change on polyacid-modified composite resin restorative materials caused by the use of various paediatric drugs. Two hundred ten discs were prepared from polyacid-modified composite resin material and divided into two groups: flouride varnish was applied to one group and flouride varnish was not applied to the other group. The groups were further divided into seven subgroups and the samples were kept in artificial saliva, amoxicillin + clavulanic acid, cefuroxime axetil, clarithromycin, paracetamol, ibuprofen, and iron supplement drug solutions. The colour change values of the discs were measured using a spectrophotometer device before immersion in the drug solutions and on the 7th, 14th, 21st, and 28th days after the immersion. The obtained data were calculated and statistically evaluated using IBM SPSS V23 software. It was found that the application of fluoride varnish in the iron supplement drug group prevented the colour change of the polyacid-modified composite resins for 28 days. In the amoxicillin + clavulanic acid, cefuroxime axetil, and paracetamol groups, the fluoride varnish did not prevent colour change in the polyacid-modified composite resin restorative materials at the end of the 14th day. It is thought that fluoride varnish application may be beneficial as a preservative in the colour change of polyacid-modified composite resins due to the use of various paediatric drugs, and this protective feature may be effective for a specific period of time.

Effects of Fluoride Varnish on Roughness of Polyacid-Modified Composite Resins at Different Temperatures: An In Vitro Study

Aim: The purpose of this study is to determine how fluoride varnish materials applied to polyacid modified composite resins (PMCR) affect roughness at various temperatures. Materials and Methods: In total, 100 PMCR discs were manufactured for this in vitro study, and the hundred samples were randomly split into five groups of twenty samples each. The samples in four groups had their surfaces coated with fluoride varnish at varying temperatures (4ºC, 23ºC, 39ºC, and 55ºC), while the samples in the control group did not get this treatment. A heating device is used for fluoride varnish. A profilometer was used to measure the samples’ surface roughness values after application. The Kruskal–Wallis and Shapiro–Wilk tests were used for statistical analysis. Results: After comparing five groups with twenty samples apiece, it was found that 23ºC had the greatest average roughness value. For the fluoride varnish material cooked at various temperatures, there was no discernible statistical variation in the roughness values. Conclusion: The study’s results indicate that all groups’ surface roughness values following the application of fluoride varnish at varying temperatures were found to be clinically acceptable.

Effects of Different Anti-Epileptic Drug Groups and Brushing on the Color Stability of Restorative Materials Used in Pedodontics: An In Vitro Evaluation.

This study will evaluate the effects of anti-epileptic drugs and brushing used in children on the color change of three restorative materials by creating an in vitro study model. Forty samples of polyacid-modified composite resin (compomer), glass ionomer cement (GIC), and composite resin (CR) were prepared. Samples were split into four groups (n = 10) and soaked in three anti-epileptic drugs (Tegretol, Depakine, Keppra) and distilled water. For each group (n = 5), two subgroups (brushing and non-brushing) were created. Discolorations [CIEDE2000 (ΔE00)] were determined initially and on days 7 and 14. The data were analyzed with a four-factor repeated measures ANOVA analysis, and a post hoc analysis Bonferroni test was used. After the second week, the highest ΔE00 value was seen in the non-brushed compomer material in the Tegretol drug group (8.59 ± 0.43). In contrast, the lowest value was seen in GIC filling material-brushing-Depakine drug (3.45 ± 2.14). ΔE00 values in the brushing groups were statistically significantly lower than those in the no brushing groups (p < 0.05). It has been determined that the color stability of aesthetic restorative dental materials used in pediatric dentistry is affected by antiepileptic drugs. In addition, it has been determined that tooth brushing positively affects the color stability of restorative materials. Therefore, pediatric dentists should advise their patients and their relatives about this issue and take precautions.

Comparative evaluation of probiotic solutions on surface roughness and microhardness of different restorative materials and enamel.

This research study aimed to investigate the impact of probiotic mouthwash and kefir on the surface characteristics, specifically surface roughness and microhardness, of different restorative materials, as well as permanent and deciduous tooth enamels. Thirty disc-shaped specimens were prepared from composite resin (G-ænial Posterior (GP)), polyacid-modified composite resin (compomer) (Dyract-XP (DXP)), and resin-modified glass ionomer cement (Ionoseal (IS)). Additionally, thirty specimens of enamel were obtained from permanent teeth (PT) and thirty from deciduous teeth (DT) by embedding buccal and lingual sections, acquired through vertical sectioning of 15 permanent and 15 deciduous human tooth crowns in the mesiodistal orientation within acrylic resin blocks. The specimens were then categorized into three distinct groups and immersed for 14 days in one of the following solutions: distilled water, kefir or probiotic mouthwash. The mean surface roughness values of all specimens were assessed using an atomic force microscope, while the mean surface microhardness was measured using a Vickers hardness measuring instrument. The results revealed a statistically significant difference in mean surface roughness among the various restorative materials (p < 0.001). Among the restorative materials, the IS material exhibited notably higher mean surface roughness values than other restorative materials and tooth enamel, while no significant differences were observed between the PT and DT groups. Importantly, the main effect of the solutions under investigation was not statistically significant (p = 0.208). No significant difference was found between the surface roughness values of specimens subjected to the different solutions. When evaluating the effects of materials and solutions on microhardness, the main effects of material and solution variables and the influence of material-solution interactions were statistically significant (p < 0.001). Taken together, these results indicate that consistent use of kefir or probiotic mouthwashes may impact the surface properties of various restorative materials and tooth enamel.

Evaluation of gap formation for different adhesive agents in primary teeth with optical coherence tomography.

This study aimed to evaluate gap formation between the tooth surface and restorative material in terms of microleakage by using optical coherence tomography (OCT) for self-etch and selective-etch applications of two different universal and one self-etch adhesives. Sixty non-caries, primary molar teeth were divided into six groups; self-etch and selective-etch application ways of two different universal and one self-etch adhesive systems (n:10). After Class-V cavities were prepared, every tooth was distributed randomly in groups to apply adhesion procedure and then, all cavities were restored with polyacid-modified composite resin. Microleakage was evaluated by measuring the gap between the tooth surface and restoration by a blind researcher with Image J Software from OCT images. During statistical analysis, the significance level was accepted as p<0.05. According to the statistical analysis of the measurements obtained by Image J Software, selective-etch groups showed less gap formation than self-etch groups for each tested adhesive (p<0.05), and self-etch adhesive without etching showed significantly highest gap formation among all groups (p<0.05). Universal adhesives with a selective-etching step might be preferred over self-etch adhesives for long-lasting polyacid-modified composite resin restorations in primary teeth. However, obtained results should be considered with another prospective clinical study for long-term prognosis.

Comparative Evaluation of Shear Bond Strength of Glass Ionomer Cement, Composite and Compomer in Primary Teeth: An In Vitro Study

Background: Because the main dislodging pressures at the tooth restoration interface have a shearing effect, shear bond strength is crucial for the restorative material clinically. Therefore, greater shear bond strength suggests improved material to tooth bonding. Glass ionomer cement and composite is the most popularly used restorative material. Composite resins have better mechanical properties and esthetics than many other types of cement, but they need bonding agents as they are hydrophobic and hence fail to adhere to the teeth. Compomers are polyacid modified resin composites. Compomer and composite resin have similar physical properties, as they are thought to bond to dentin by micromechanical bonding. As resin composites are used in this, the polymerized acid monomer shows acidity when it comes in contact with the saliva and there is a reaction of fluoride-containing basic glass resulting in the cariostatic effect. Aim: The purpose of this study was to evaluate and compare the shear bond strength of Glass Ionomer Cement (Fuji IX GP), Composite Resin (Filtek Z-250) and Compomer, (Compoglass, Ivoclar). Material and Method: An in-vitro, experimental study was conducted on 30 freshly extracted over-retained deciduous molars. Samples were randomly divided into three groups depending on the material to be used. Flat dentinal surface on tooth was prepared over which restorative materials were placed. The prepared specimen was subjected to shear test and the value obtained was compared. Descriptive statistical analysis was performed to calculate the mean shear bond strength of each group. Result: It was observed from the study that the composite resin had the highest shear bond strength value (17.13 ± 1.54), followed by compomer (11.32 ± 1.05) whereas GIC showed the least shear bond strength (6.56 ± 0.87). Conclusion: It was concluded that composite restorative materials show higher shear bond strength than glass ionomer cement and compomer in primary molars, but shear bond strength of compomer was higher than that of glass ionomer cement.

Effect of topical fluoride applications on residual monomer release from resin-based restorative materials

BackgroundThe effects of topical fluoride applications on the release of monomer ingredients from resin-based dental materials by immersion in various extraction solutions are unclear. The aim of this study was to determine the effect of topical fluorides (APF and NaF) on the elution of residual monomers (Bis-GMA, TEGDMA, UDMA, and HEMA) from resin-based materials.MethodsNinety specimens were prepared, 30 bulk-fill composite resin, 30 nanohybrid universal composite resin, and 30 polyacid-modified composite resin (compomer). These were randomly divided into three groups based on fluoride application procedures. Each specimen was kept in 75% ethanol solution, and residual monomers released from materials were analyzed using high-performance liquid chromatography (HPLC) after 10 min, 1 h, 24 h, and 30 days. The groups were compared using the Mann Whitney U and Kruskal Wallis tests. Measurements were analyzed using the Friedman and Wilcoxon signed-rank tests.ResultsFluoride applications generally had no considerable effect on the amount of residual monomer released from resin-based restorative materials. The amount of monomer release after topical APF application was similar to the release in the control group and was lower than the release in the NaF group. The release of monomers from the resin-based material used in the study did not approach toxic levels at the applied time intervals. The compomer released lower amounts of monomer than other resin-based materials.ConclusionsFluoride applications do not increase monomer release from resin-based restorative materials. However, compomers should be employed by clinicians due to their lower monomer release compared to other resin restorative materials. The release of monomers from all the resin-based materials did not approach toxic levels at the applied time intervals.

The color change effect of children's beverages on preheated polyacid-modified composite resins

AimColor stability is crucial to the esthetic success of restorative materials. The research carried out on the development of restorative materials, especially the preheating process to resins draws attention due to some advantages. The purpose of the research was to examine the effect of preheated polyacid-modified composite resins of children's beverages on color stability in vitro.Materials and methodsThe discs were prepared from A2-colored polyacid-modified composite resin material preheated at four different temperatures (4, 23, 39, and 55°C). The discs were kept in distilled water, cola, cherry juice, and chocolate milk. The data obtained by calculating the color changes were statistically evaluated using a two-way robust analysis of variance.ResultsNo significant color change was observed in the chocolate milk group compared to the distilled water group at all preheating temperatures on the working period. In the cola group, a similar color change was observed for up to 60 days at pretemperature values of 39 and 55°C, and up to 30 days at temperatures of 4 and 23°C.ConclusionIt should be considered that the preheating process may be beneficial for the longevity of the color stability of restorations, and that different beverage groups may have different effects.

Susceptibility to discoloration of dental restorative materials containing dimethacrylate resin after bleaching.

The aim of this study is to compare the susceptibility to discoloration of dental restorative materials containing dimethacrylate resin after bleaching. In this study, resin-modified glass ionomer, polyacid-modified composite resin, giomer, posterior composite resin, anterior composite resin, bulk fill composite resin, flowable bulk fill composite resin, ormocer, indirect composite resin and hybrid ceramics were used as restorative material containing dimethacrylate resin. 20 samples were prepared from each material in accordance with the manufacturer's instructions. After the baseline colors are measured, the samples were randomly divided into four subgroups as office bleaching, home bleaching and a separate control group for each type bleaching method. Then, the samples were bleached and colored. Color measurements of the samples were repeated after exposure to bleaching and coloring. Then, ΔE00 and whiteness index (WID) were calculated. Data were analyzed using Paired-Samples T Test, two-way ANOVA, Repeated Measures ANOVA and Tukey post-hoc tests. Statistical significance level was taken as p < 0.05. In terms of bleaching systems, Opalescence Boost was found to cause more whitening in materials but more discoloration (p < 0.05). In terms of materials, it was found that the most susceptible materials to coloration were Clearfil Majesty Posterior, Filtek Bulk Fill Posterior Restorative, Filtek Bulk Fill Flowable and Fuji II LC, while the least susceptible materials were CAD/CAM materials (p < 0.05). The bleaching process increases the susceptibility to coloration of materials containing dimethacrylate resin.

A Scanning Electron Microscope Evaluation of the Efficacy of Different Fluoride-releasing Dental Restorative Materials to Prevent Enamel Demineralization: An In Vitro Study

Aim of the present research was to investigate the effectiveness of various fluoride-releasing dental restorative agents in preventing demineralization of enamel. Eighty human mandibular permanent molar teeth constituted the study group. All samples were subjected to storage in thymol, after which they were taken out to prepare alike proximal box in each. Inductions of artificial enamel surface lesions were done by placing the teeth in demineralizing solution for 96 hours. Subsequently, all 80 molars were randomly assigned to any of the four groups (i.e., 20 in every individual group) according to the restoration as group A: giomer (composite resin containing surface pre-reacted glass-ionomer fillers), group B: compomer (polyacid-modified composite resin), group C: resin-modified glass-ionomer cement (RMGIC), group D: fluoride-releasing composite. After this, the pH cycling was performed, and the samples were subjected to examination beneath scanning electron microscope (SEM). Higher mean areas of remineralization were noted when RMGIC (96.34 ± 0.06) was used followed by the compomer (109.52 ± 0.17), giomer (118.39 ± 0.82), and the fluoride-releasing composite group (129.27 ± 0.31) in that order. A statistically significant difference was seen amid the investigational groups that utilized different restorative agents (p <0.001). A pairwise evaluation that was performed revealed that except for the giomer group and the compomer group, a statistically significant difference (p <0.001) was found among the experimental groups. This research infers that the RMGIC-treated samples exhibited significantly superior performance in preventing enamel demineralization in comparison to compomer, giomer as well as fluoride-releasing composites. One among the highly frequently employed anticariogenic materials is fluorides. Owing to this characteristic, they are integrated into numerous restorative substances. Nevertheless, the quantity and speed of fluoride release differ in different agents, which translates to the efficacy of the restorative agent in avoiding demineralization about the restoration.

Influence of fluoride-releasing materials in the inhibition of enamel and dentin demineralization around restoration

Objective: The aim was to evaluate the influence of fluoride-releasing restorative materials in enamel and dentinmicrohardness. Material and Methods: 40 blocks (5x5x3 mm) from cervical third of human molars received a cavitypreparation between the enamel and dentin, and the restorations were subjected to in vitro caries model. Specimenswere randomly restored with (n=10): conventional glass ionomer cement (Ketac Cem, 3M ESPE); polyacid-modifiedcomposite resin (Ionoseal, VOCO); resin-modified glass ionomer cement (Ionofast, Biodinâmica); or microhybridcomposite resin (Filtek Z250, 3M ESPE). The specimens were sectioned longitudinally and enamel and dentinKnoop microhardness were determined at different distances from the restorative material (100, 200 and 300 um)and depth of surface (20, 40 and 60 um). The data were submitted to three-way repeated measures ANOVA andTukey´s test (a=0.05). Results: For enamel, the double interactions between material x distance and material xdepth were statistically significant. In all depths and distances, the highest values of enamel microhardness wereobserved for Ketac Cem. In dentin, the materials differed statistically from each other, and Ionoseal obtained highermicrohardness values than those found in Ionofast. Conclusion: Conventional glass ionomer cement is more effectivein preventing enamel demineralization around restoration followed by the polyacid-modified composite resin. Indentin, the polyacid-modified composite resin obtained better performance than resin-modified glass ionomer cement.KEYWORDSCompomers; Dental caries; Glass ionomer cements; Hardness tests; Composite Resins.

Tooth-coloured materials for class II restorations in primary molars: systematic review and meta-analysis.

The aim of this systematic review was to compare the success rate of five tooth-coloured materials, namely Glass Ionomer (GI), Resin-Modified Glass Ionomer (RMGI), Composite Resin (CR), Polyacid-Modified Composite Resin or Compomer (CO) and High-Viscosity Glass Ionomer (HVGI) in primary molar Class II restorations. Five databases were searched from inception to April 23, 2020 for randomized clinical trials comparing the failure rate of these materials. After duplicate study removal, data extraction and risk of bias assessment with the Cochrane tool, data synthesis was conducted, comparing all five tooth-coloured materials in pairs and computing the overall success rate for each one, respectively. A total of 5615 articles were obtained by electronic and hand literature search. After the application of the eligibility criteria, ten RCTs were included in this systematic review and six RCTs for meta-analysis. Their risk of bias was assessed to be high to moderate. Due to the small number of RCTs comparing the five restorative materials in pairs investigated in the same study, only three MAs were available for heterogeneity assessment. These were: (1) between CO-RMGI (RR 1.04 [0.59, 1.84]; p = 0.88; I2 = 1%), (2) CR-CO (RR 1.12 [0.41, 3.02]; p = 0.83; I2 = 57%), and (3) between CR-RMGI (RR 1.10 [0.74, 1.63]; p = 0.65; I2 = 0%). No statistically significant differences were found between the two materials in all three comparisons. CR, RMGI and CO presented no statistical differences. In comparison to other tooth-coloured materials, studies on GI were too few to allow recommendations about its use. More studies on HGVI are needed for evidence-based recommendations to be made. The evidence extracted from this meta-analysis was not strong enough (moderate), due to the small number of RCTs and the risk of bias ranging from high to moderate. More, well-designed RCTs comparing tooth-coloured materials for primary molar Class II restorations are necessary.

Does Pigment Incorporation into Regular Composite Resins for Posterior Buildups Alter Their Bond Strength?

Posterior build-ups are auxiliary devices to orthodontic treatment which are made with resin-based or glass ionomer composites. Their removal requires care to protect the tooth surface, therefore, pigmented materials are preferred for a better visualization. This study proposed a pigmentation experimental technique of a regular composite resin, evaluating the microshear bond strength test (µ-SBT) of this experimental pigmented resin and comparing with a blue-colored polyacid-modified composite resin, used for posterior buildups. Forty-eight buccal and lingual surfaces of human teeth were used and randomly divided into 4 groups (n=12). The groups were divided into: C (control), regular composite resin; P, regular composite resin pigmented; UBL, Ultra Band Lok™; OB, Ortho Bite™. The composites were bonded using a matrix to obtain microcylinders and prepared for each experimental groups. The samples were then stored in distilled water for 24h at 37°C followed by a µ-SBT. The types of bond failures were evaluated using a stereoscopic magnifying glass (10×). The data were analyzed by ANOVA with Fisher post hoc and Dunnett´s test. Means of µ-SBT± standard deviation (MPa) were: C (39.98a±13.0), P (40.09a± 14.3); UBL (33.26ab±8.6); OB (28.70b±5.5). The most prevalent type of failure was adhesive (80.4%). Further, was not observed a statistically significant correlation between the bond strength values and failure patterns. The pigmentation of a commercially available resin did not alter the µ-SBT and exhibited similar adhesiveness as a polyacid-modified composite resin.

Class II Restoration Using Bioactive Restorative Material vs Polyacid Modified Composite Resin in Primary Molars

Class II Restoration Using Bioactive Restorative Material vs Polyacid Modified Composite Resin in Primary Molars

Evaluation of The Microleakage of Polyacid Modified Composite Compared to Hybrid Composite and Resin Modified Glass Ionomer Cement in Primary and Permanent Teeth Restoration (An in vitro study)

Background: Dental caries is one of the most significant problems in world health care. Restoring carious primary teeth is one of the major treatment goals for Children, and the light activated resin restoration materials like composite, resin-modified glass ionomer and polyacid-modified which was introduced in dentistry in 1970, widely used in clinical dentistry but its application increased dramatically in recent years because of its biocompatibility, color matching, good adhesive properties of its resemblance in physical and mechanical aspects to tooth. The aim of this study: To evaluate the microleakage of Polyacid-Modified Composite resin Compared to Flowable Hybrid Composite and Resin-Modified Glass ionomer cement. Materials and methods: Thirty extracted primary molar teeth and thirty extracted permenant premolar teeth were used in this study 20 for each material, then standardized Class V cavities of teeth was prepared in the buccal and lingual surfaces. Using Polyacid-modified composite Resin (Compomer), flowable composite resin and Resin-modified glass Ionomer RMGI. The samples will be divided into three groups according to type of restorative material used and light cured with a light cure device (Ivoclar Vivadent Bluephace), after complete curing the sample will examined by Scanning electron microscope (SEM) and then measure the microleakage. Results: The RMGI shows the statistically significantly lowest mean value of microleakage, followed by Compomer shows statistically significantly lower mean value. Flowable Composite shows the statistically significantly highest mean microleakage. There is no statistically significant difference in microleakage values between the permanent and primary teeth. Conclusion: The Resin-modified glass Ionomer is better in term of microleakage than Polyacid-modified composite Resin and Flowable Composite.

Effect of exposure time and pre-heating on the conversion degree of conventional, bulk-fill, fiber reinforced and polyacid-modified resin composites

ObjectiveTo determine the degree of conversion (DC) of different type of resin-based composites (RBC) in eight-millimeter-deep clinically relevant molds, and investigate the influence of exposure time and pre-heating on DC. MethodsTwo-millimeter-thick samples of conventional sculptable [FiltekZ250 (FZ)], flowable [Filtek Ultimate Flow (FUF)] and polyacid-modified [Twinky Star Flow (TS)] RBCs, and four-millimeter-thick samples of flowable bulk-fill [Filtek Bulk Fill Flow (FBF), Surefil SDR (SDR)] and sculptable fibre-reinforced [EverX Posterior (EX)] RBCs were prepared in an eight-millimeter-deep mold. The RBCs temperature was pre-set to 25, 35 and 55°C. The RBCs were photopolymerized with the recommended and its double exposure time. The DC at the top and bottom was measured with micro-Raman spectroscopy. Data were analyzed with ANOVA and Scheffe post-hoc test (p<0.05). ResultsThe differences in DC% between the top/bottom and the recommended/extended exposure time were significant for the materials, except SDR (64.5/63.0% and 67.4/63.0%). FUF (69.0% and 53.4%) and TS (64.9% and 60.9%) in 2mm provided higher DC% at the top and bottom with the recommended curing time, compared to the other materials, except SDR. Pre-heating had negative effect on DC at the bottom in flowable RBCs (FUF: 48.9%, FBF: 36.7%, SDR: 43%, TS: 54.7%). Pre-heating to 55 °C significantly increased the DC% in fibre-reinforced RBC (75.0% at the top, 64.7% at the bottom). SignificanceIncreased exposure time improves the DC for each material. Among bulk-fills, only SDR performed similarly, compared to the two-millimeter-thick flowable RBCs. Pre-heating of low-viscosity RBCs decreased the DC% at the bottom. Pre-heating of fibre-reinforced RBC to 55°C increased the DC% at a higher rate than the extended curing time.

Biodegradation of resin–dentin interfaces is dependent on the restorative material, mode of adhesion, esterase or MMP inhibition

ObjectiveTo measure the effect of simulated human salivary esterases (SHSE) and metalloproteinases (MMP) inhibition on the integrity of restoration–tooth interfaces made from traditional or polyacid-modified resin composites bonded to human dentin by either total-etch or self-etch adhesives. MethodsResin–dentin specimens, made from traditional (Z250) or polyacid-modified (Dyract-eXtra) composites were bonded to human dentin using total-etch (TE-Scotchbond) or self-etch (SE-EasyBond) adhesives. TE was applied with or without the MMP inhibitor galardin. Specimens were incubated in phosphate-buffer or SHSE (37°C/pH=7.0) for up to 180 days, then suspended in a continuous flow biofilm fermenter cultivating biofilms of Streptococcus mutans UA159. Interfacial bacterial penetration, biofilm biomass and viability were measured by confocal laser scanning microscopy and biomarker dyes and used as interfacial biodegradation markers. ResultsAll specimens showed increased biofilm penetration and biomass with time regardless of incubation condition. SHSE increased bacterial penetration in all experimental samples after 180days (p<0.05). Galardin reduced interfacial bacterial ingress and bacterial biomass vs. non-MMP-inhibited TE-bonded specimens (p<0.05). TE interfaces showed lower interfacial bacterial biomass vs. SE after 90-day and 180-day (p<0.05). Dyract-eXtra specimens showed lower bacterial cell viability within the interface vs. Z250 (p<0.05). SignificanceThe biodegradation of resin–tooth interfaces is accelerated by esterases, modulated by MMP inhibition and is dependent on the material’s chemistry and mode of adhesion. The in vitro bacterial growth model used in this study facilitates the elucidation of differences in interfacial integrity and biostability between different materials and techniques and is suitable for assessment of their performance prior to clinical evaluation.

Adhesives for fixed orthodontic brackets.

Bonding of orthodontic brackets to teeth is important to enable effective and efficient treatment with fixed appliances. The problem is bracket failure during treatment which increases operator chairside time and lengthens treatment time. A prolonged treatment is likely to increase the oral health risks of orthodontic treatment with fixed appliances one of which is irreversible enamel decalcification. This is an update of the Cochrane Review first published in 2003. A new full search was conducted on 26 September 2017 but no new studies were identified. We have only updated the search methods section in this new version. The conclusions of this Cochrane Review remain the same. To evaluate the effects of different orthodontic adhesives for bonding. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 26 September 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 8) in the Cochrane Library (searched 26 September 2017), MEDLINE Ovid (1946 to 26 September 2017), and Embase Ovid (1980 to 26 September 2017). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Trials were selected if they met the following criteria: randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing two different adhesive groups. Participants were patients with fixed orthodontic appliances. The interventions were adhesives that bonded stainless steel brackets to all teeth except the molars. The primary outcome was debond or bracket failure. Data were recorded on decalcification as a secondary outcome, if present. Information regarding methods, participants, interventions, outcome measures and results were extracted in duplicate by pairs of review authors. Since the data were not presented in a form that was amenable to meta-analysis, the results of the review are presented in narrative form only. Three trials satisfied the inclusion criteria. A chemical cured composite was compared with a light cured composite (one trial), a conventional glass ionomer cement (one trial) and a polyacid-modified resin composite (compomer) (one trial). The quality of the trial reports was generally poor. There is no clear evidence on which to make a clinical decision of the type of orthodontic adhesive to use.

Clinical performance of resin-modified glass ionomer cement, flowable composite, and polyacid-modified resin composite in noncarious cervical lesions: One-year follow-up.

Background:The restoration of noncarious cervical lesions (NCCLs) often poses a challenge to the clinician. Various restorative materials are available in the market for the restoration of the same. Each material has various advantages and shortcomings.Aim:The aim of this study was to compare and to evaluate the clinical performance of capsulated resin-modified glass ionomer cement (RMGIC), flowable composite, and polyacid-modified composite resin (PMCR) in NCCLs.Materials and Methods:A total of 101 restorations were placed among healthy controls in this clinical trial. A total of 101 restorations were divided into three groups with n = minimum 32 per group (Group 1: 33 restorations, Group 2: 34 restorations, and Group 3: 34 restorations). The restorative materials used were capsulated RMGIC, flowable composite and PMCR. After the placement, the restorations were evaluated for the United States Public Health Services criteria for six parameters, namely retention, marginal adaptation, marginal discoloration, color stability, surface roughness, and sensitivity. The restorations were evaluated at baseline, 6 and 12 months.Statistical Analysis:Statistics was performed using SPSS 21.0 version. Chi-square test was done to compare the proportions between groups. Fisher's exact test was used to compare proportion change between time points.Results:There was no statistically significant difference seen among the three groups for retention, color stability, surface roughness, and hypersensitivity. RMGIC had shown superior characteristics in marginal adaptation and marginal discoloration compared to flowable composite and PMCR, and the difference was statistically significant.Conclusion:Within the limitations of this study, all the three restorative materials are clinically acceptable for the restoration of NCCLs. RMGIC is superior regarding marginal adaptation and esthetics for restoring NCCLs.

Microleakage of glass ionomer based restorative materials in primary teeth: An In vitro study.

Using AutoCAD, we examined the microleakage of dye at the edges of primary-teeth restorations using three glass ionomer-based restorative materials. A total of 30 extracted noncarious primary molars were used. Class V cavities were adjusted on the buccal surfaces. The teeth were randomly divided into three groups of 10 teeth each as follows: Group A (Ketac Molar), Group B (Photac Fil), and Group C (Dyract XP). All specimens were stored for 24 h at 37°C in distilled water. The teeth were thermocycled 1000 times between 5°C ± 2°C and 55°C ± 2°C before immersion in 0.5% basic fuchsin for 24 h. Two mesiodistal cuts of each tooth were photographed under a stereomicroscope equipped with a digital camera. The dye-infiltrated surface area was measured. Statistical evaluations were performed by the Kolmogorov-Smirnov test, Levene test, one-way analysis of variance, and Tukey's honestly significant difference test. The mean microleakage ratio differed significantly among the groups (P < 0.05). Group C exhibited a significantly smaller area (P < 0.001) than the other groups. Group A had a nonsignificantly higher mean microleakage value than Group B (P > 0.05). Polyacid-modified composite resin may be a useful restorative material in primary teeth in terms of minimizing microleakage.