Effects of frequently consumed beverages by children on the surface roughness of compomers.

PURPOSE: To evaluate and compare changes on the surface roughness of conventional and colored compomers used in pediatric dentistry caused by beverages frequently consumed by children. METHODS: 176 conventional and colored compomer discs were prepared. The discs were divided into four equal subgroups and incubated in different beverages: distilled water, milk, fruit juice, and cola. The surface roughness of the samples was measured and recorded on Days 1, 7, 14, 21, and 28. The data obtained were statistically analyzed. RESULTS: In distilled water and milk, the surface roughness of the conventional compomer was higher than the colored compomer after Day 7 (P< 0.05). In fruit juice and cola, the surface roughness of conventional and colored compomers was similar at all timepoints (P< 0.05). There was a significant difference between discs incubated in distilled water and milk, on Days 21 and 28 (P< 0.05). The colored compomer showed the highest roughness in cola on Day 1, whereas the conventional compomer showed the highest roughness in milk on Day 21. CLINICAL SIGNIFICANCE: Cola caused the highest surface roughness on the surface of colored compomers, whereas milk caused the highest surface roughness on conventional compomers.

Comparative analysis of shear bond strength of MTA and Theracal PT with different restorative materials.

BACKGROUND: This study aimed to compare the in vitro shear bond strength (SBS) of mineral trioxide aggregate (MTA) and dual-cured, resin-modified calcium silicate material (Theracal PT) to composite resin, compomer, and bulk-fill composite, and to evaluate the bond failure mode under a stereomicroscope. METHODS: Ninety acrylic specimens, each with a 4 mm diameter and 2 mm height central hole, were prepared. These specimens were randomly divided into two groups based on the capping materials: MTA and Theracal PT. Each group was further subdivided into three subgroups (n = 15) according to the restorative materials: composite resin, compomer, and bulk-fill composite. The specimens were then subjected to shear testing using a universal testing machine at a crosshead speed of 1 mm/min. Post-test, the fracture locations were examined using a stereomicroscope. Data were analyzed using a two-way analysis of variance (ANOVA) and the Tukey test. RESULTS: The SBS values for the Theracal PT group were significantly higher than those for the MTA group (p < 0.001). Within the MTA groups, no significant differences were observed in SBS values across the different restorative materials. However, a significant difference was found between the mean SBS values of the Theracal PT + composite resin group and the Theracal PT + compomer group (p < 0.001). CONCLUSIONS: Theracal PT shows promise in dentistry due to its superior bond strength. Given its bond values, Theracal PT appears capable of forming durable and long-lasting restorations by establishing reliable bonds with various restorative materials commonly used in dentistry.

Two-year clinical and radiographic evaluation of ACTIVA BioACTIVE versus Compomer (Dyract® eXtra) in the restoration of class-2 cavities of primary molars: a non-inferior split-mouth randomised clinical trial.

OBJECTIVES: The trial aimed to compare the clinical performance and radiographic success of ACTIVA BioACTIVE versus Compomer in restoring class-II cavities of primary molars. MATERIALS AND METHODS: A non-inferior split-mouth design was considered. A pre-calculated sample size of 96 molars (48 per group) with class-2 cavities of twenty-one children whose ages ranged from 5 to 10 years were randomly included in the trial. Pre-operative Plaque Index (PI), DMFT/dmft scores and the time required to fill the cavity were recorded. Over 24 months, the teeth were clinically evaluated every six months and radiographically every 12 months by two calibrated and blinded evaluators using the United States public health service (USPHS)-Ryge criteria. The two-sided 95% confidence interval (CI) for the difference in success rate was considered to assess non-inferiority, and the margin was set at -18%. The linear mixed model and Firth's logistic regression model were used for data analysis (P < 0.05). RESULTS: After 24 months, 86 teeth (43 per group) were evaluated. The mean PI score was 1.1(± 0.9), while DMFT/dmft was 0.35 (± 0.74) and 6.55 (± 2.25) respectively. The clinical and radiographic success rate of Dyract vs. ACTIVA was 95.3% and 88.3% vs. 93% and 86%, respectively. The two-sided 95% CI for the difference in success rate (-2.3%) was - 3.2 to 1.3% and didn't reach the predetermined margin of -18% which had been anticipated as the non-inferiority margin. Clinically, ACTIVA had a significantly better colour match (P = 0.002) but worse marginal discolouration (P = 0.0143). There were no significant differences regarding other clinical or radiographic criteria (P > 0.05). ACTIVA took significantly less placement time than Dyract, with a mean difference of 2.37 (± 0.63) minutes (P < 0.001). CONCLUSION: The performance of ACTIVA was not inferior to Dyract and both materials had a comparable high clinical and radiographic performance in children with high-caries experience. ACTIVA had a significantly better colour match but more marginal discolouration. It took significantly less time to be placed in the oral cavity. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov on 4 May 2018 (#NCT03516838).

Effect of Bonding Agents on the Shear Bond Strength of Tooth-colored Restorative Materials to Dentin: An In Vitro Study.

AIM: The aim of the study is to determine the difference in the shear bond strengths to dentin among dental composite (Filtek Z350®, 3M), compomer (Dyract Flow®, Dentsply) and Giomer (Beautifil®, Shofu) with 3MTM Single BondTM Universal Adhesive (SBU) (7th generation, self-etch, single solution adhesive) and AdperTM Single Bond 2 Adhesive (ASB) (5th generation, total-etch, two solution adhesive). MATERIALS AND METHODS: Sixty extracted human permanent teeth were collected, cleansed of debris, and placed in distilled water. The samples were segregated into two groups depicting the two bonding agents-AdperTM (ASB) and 3MTM Single Bond Universal (SBU) and sub-grouped into three groups depicting the three restorative materials (Composite, Giomer, and Compomer) used. Groups were respresented as follows: Group I-ASB + Composite; Group II-ASB + Giomer; Group III-ASB + Compomer; Group IV-SBU + Giomer; Group V-SBU + Compomer; Group VI-SBU + Composite. After applying the bonding agent as per the manufacturer's instructions, following which the restorative material was placed. A Universal Testing Machine (Instron 3366, UK) was employed to estimate the shear bond strength of the individual restorative material and shear bond strengths were calculated. RESULTS: Composite bonded with SBU (group VI) displayed the greatest shear strength (11.16 ± 4.22 MPa). Moreover, Giomers and flowable compomers displayed better bond strengths with ASB compared with their SBU-bonded counterparts. CONCLUSION: These results mark the importance of careful material selection in clinical practice and the bonding agent used to achieve optimal bond strength and enhance the clinical longevity and durability of dental restorations. CLINICAL SIGNIFICANCE: From a clinical perspective, to avoid a compressive or a shear failure, it would be preferrable to use a direct composite restorative material with SBU (Single bond universal adhesive, 7th generation) to achieve maximum bond strength. How to cite this article: Kuchibhotla N, Sathyamoorthy H, Balakrishnan S, et al. Effect of Bonding Agents on the Shear Bond Strength of Tooth-colored Restorative Materials to Dentin: An In Vitro Study. J Contemp Dent Pract 2024;25(3):245-249.

Residual Monomer Release after the Polymerization of Different-Colored Flowable Compomer.

BACKGROUND: Compomers are restorative materials commonly used in pediatric dentistry. It is important to investigate the monomer release of materials used especially in pediatric patients. The aim of this study was to evaluate the residual monomer released from different-colored flowable compomers at five polymerization times. MATERIALS AND METHODS: Three experimental groups were formed: Group 1: pink flowable compomer (Twinky Star, VOCO, Germany), Group 2: blue flowable compomer (Twinky Star, VOCO), Group 3: white flowable compomer, A2 color of Dyract XP (Dentslpy DeTrey, Konstanz, Germany). For each group, samples were prepared using standard cylindrical Teflon molds (n = 10), and the compomers were cured using a light-emitting diode (LED) source in accordance with the manufacturer's recommendations. During each time period, the number of residual monomers: bisphenol-A glycidyl methacrylate (bis-GMA), urethane dimethacrylate (UDMA), hydroxyethyl methacrylate (HEMA), and triethylene glycol dimethacrylate (TEGDMA) were determined with high-performance liquid chromatography (HPLC). All data were analyzed statistically. RESULTS: In all groups, the amount of residual monomers increased after 1-h release periods (P < 0.05). For 2 weeks, the total residual monomers released were determined at most in Group 3 and at least in Group 1. However, there was no significant difference between the groups in terms of released amounts of monomers (P > 0.05). CONCLUSIONS: According to the study, when the total amount of residual monomer released from all groups was compared, no difference was found and it was observed that none of them exceeded the toxic dose. Flowable colored compomers can be used as safely as white compomers in pediatric dentistry.

Evaluation of failure rate of molar tubes with a modified bonding technique: a randomized clinical trial.

BACKGROUND: During orthodontic therapy, bond failure of molar tubes may delay treatment. With the high failure rate of molar tubes, alternative bonding techniques were tested to improve bond strength. OBJECTIVES: To compare the failure rates of molar tubes bonded with conventional and alternative bonding techniques by adding a layer of compomer adhesive at the molar/tube interface. TRIAL DESIGN: Single-centre, single-blinded, split-mouth, randomized clinical trial. METHODS: Patients aged 12 years or older, who required fixed appliance orthodontic treatment without extraction and with no occlusal interference were eligible to participate. They were allocated randomly using a simple non-stratified split-mouth design with a 1:1 allocation ratio. Blinding was only possible for the patients and data analysts. Molar tubes bonded with the modified bonding technique had an additional layer of compomer at the occlusal molar/tube interface. The patients were followed-up for nine months. Outcome measures included the survival time of molar tubes and the number of molar tubes debonded. The bond failure of molar tubes was analyzed using Kaplan-Meier and Cox regression analysis (P < 0.05). RESULTS: Thirty patients were recruited, randomized, and analyzed (mean age 20.33 years). The failure rate of molar tubes bonded with the modified bonding technique was 4.2 per cent and that of molar tubes bonded with the conventional bonding technique was 6.7 per cent. This difference was not statistically significant (P > 0.05). The dental arch and molar type were found to be as significant predictors for molar tube failure rate. No harm was detected during treatment. LIMITATIONS: The effect of compomer to reduce enamel demineralization was not tested. CONCLUSIONS AND IMPLICATIONS: The modified bonding technique did not significantly reduce the failure rate of molar tubes. The molar tubes bonded on the upper arch and second molars are more susceptible to debond. REGISTRATION: The trial was registered with ClinicalTrials.gov on 21 May 2022 (Registration number: NCT05391386). FUNDING: This research did not receive any funding.

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

BACKGROUND: The 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. METHODS: Ninety 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. RESULTS: Fluoride 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. CONCLUSIONS: Fluoride 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 effects of gastric acid on pediatric restorative materials: SEM analysis.

In this study, we aimed to demonstrate changes in the surface roughness and microhardness of three different restorative materials routinely used in pediatric dentistry (composite, compomer and resin-modified glass ionomer cement (RMCIS)) in response to continuous daily exposure to gastric acid. Twelve samples of each of type of restorative material were prepared. Eleven of the specimens were included in the gastric acid cycle. The microhardness and surface roughness of ten samples were measured before and after the cycle. Another sample included in the cycle was compared with the sample not included in the cycle by scanning electron microscopy (SEM). There was a significant difference between the groups in terms of roughness scores following gastric acid cycle (p = 0.039). RMCIS material possessed the highest roughness value. A significant difference was identified in terms of microhardness levels before and after the gastric acid cycle (p = 0.001). The most significant change was observed in the compomer material. SEM analysis, performed after the gastric acid cycle, revealed that most cracks were identified in RMCIS material; this was followed by compomer and composite materials, respectively. Our analysis indicates that the restorative materials used frequently in pediatric dental procedures, show increased surface roughness and reduced microhardness when exposed to gastric acid.

Evaluation of residual monomer release after polymerization of different restorative materials used in pediatric dentistry.

BACKGROUND: The choice of the restorative resin material to be used in pediatric dentistry is of a great importance due to the cytotoxic effects caused by residual monomers. In this study, it was aimed to investigate the amount of residual monomer released over time from different resin-based restorative materials, which are widely used in pediatric dentistry, by using high performance liquid chromatography with photodiode array detector (HPLC-PDA). METHODS: The compomers in all colors (Twinky Star and Glasiositte A2), two composites with different hybrid properties (Arabesk-GrandioSO), and RMGIC (Ionolux) samples with 2 × 5 mm diameters were prepared. The samples were polymerized with an LED light unit (CELALUX 2, VOCO, Cuxhaven, Germany) and then finishing-polishing procedures were applied. A total of 156 samples were obtained, 13 samples in each of the 12 groups. The amount of residual monomer (BIS-GMA; HEMA, TEGDMA, UDMA) (µg/mL) released into the 75% ethanol solution was determined at different times, (1st hour, 1st, 7th, 14th, and 21st day) by using HPLC-PDA. RESULTS: The residual monomer release continued on day 21 and BIS-GMA was the most released monomer in all groups. HEMA release showed a maximum increase in all the materials at day 7. The highest amount of residual monomer was detected in the gold-colored compomer. HEMA and BIS-GMA release from RMGIC was less than others in all time frames. CONCLUSIONS: The color and composition of resin-based restorative materials affect the amount of residual monomer. Pediatric dentists should prefer gold-colored compomers less than others as a restorative material, especially in deep cavities. More studies are needed about the subject.

The cytotoxic and oxidative effects of restorative materials in cultured human gingival fibroblasts.

The aim of this study was to evaluate the cytotoxic and oxidative effects of the most commonly used dental restorative materials on human gingival fibroblast cells (HGFCs). HGFCs were obtained from healthy individuals. The tested restorative materials were a microhybrid resin based composite, a compomer resin, a glass ionomer cement, and an amalgam alloy. One hundred eight cylindirical samples, 10 mm in diameter and 2 mm in height, were prepared according to ISO 10993-12:2002 specifications (n = 9 in the tested subgroups). Freshly prepared and aged samples in artificial saliva at 37 °C (7 and 21 d) were placed into well plates and incubated. Wells without dental materials were constituted as the control group. After 72 h incubation period, cytotoxicity was determined using the neutral red (NR) assay. Oxidative alterations were assessed using total antioxidant capacity (TAC) and total oxidant status (TOS) assay kits. Data were analyzed using the ANOVA and LSD post hoc tests. All tested materials led to significant decreases in the cell viability rates (33-73%) compared to the control group. Glass ionomer and resin composite were found to be more cytotoxic than amalgam alloy and compomer. The highest TAC level was observed in glass ionomer after seven-day aging and these changes prevented an increase in TOS levels. Increases in TAC levels after seven-day aging in all groups exhibited significant differences with freshly prepared samples (p < 0.05). In all material groups, TOS levels of freshly prepared samples differed statistically and significantly from samples aged for 7 and 21 d (p < 0.05). The data obtained suggested that all the tested materials exhibited cytotoxic and pro-oxidant features. Freshly prepared samples caused higher TOS levels. However, oxidant status induced by materials decreased over time.

Longevity of posterior composite and compomer restorations in children placed under different types of anesthesia: a retrospective 5-year study.

OBJECTIVES: The aims of this study were (i) to assess cumulative survival rates of class II resin-based composite and compomer restorations in primary molars with a 5-year observation period and (ii) to analyze the influence of different types of anesthesia and different localizations of the restorations in the teeth. METHODS: Patient charts of a private practice for pediatric dentistry were screened for class II resin-based composite (Spectrum TPH3) and compomer (Dyract Posterior; both Dentsply DeTrey) restorations in primary molars with a 5-year observation period used with Adper Prompt L-Pop (3M-ESPE). One restoration per patient (age ≤ 6 years at placement) was randomly selected. RESULTS: Two hundred sixty restorations were included (43% resin-based composites, 57% compomers). After 5 years, cumulative survival rates were 43% for resin-based composite and 49% for compomer restorations with no statistically significant differences. There was a tendency for higher survival rates for restorations placed under N2O inhalation sedation or general anesthesia. Distal-occlusal compomer restorations showed significantly lower survival rates (p = 0.003) as compared to mesial-occlusal compomer restorations. CONCLUSION: Within the limitations of the study, we conclude that type of restorative material as well as the type of anesthesia do not influence restoration survival rates, although restorations placed in patients receiving N2O inhalation sedation or general anesthesia tend to perform better as compared with patients receiving no anesthesia or only local infiltration. CLINICAL RELEVANCE: Resin-based composite and compomer restorations show similar survival rates of more than 43% (annual failure rates less than 11.5%) after 5 years for restoration of primary molars.

Evaluation of the Impact of Acidic Drink on the Microhardness of Different Esthetic Restorative Materials: An In Vitro Study.

AIM: The aim of this study was to assess the impact of acidic drink on the microhardness of different esthetic restorative materials. MATERIALS AND METHODS: Sixty samples (20 samples of each group) were prepared. group I: nanohybrid ormocer-based composite, group II: glasiosite compomer, and group III: nanoceramic composite. A cylindrical aluminum mold of 5 mm depth and 10 mm internal diameter was used to prepare the samples. All the esthetic restorative samples were submerged in 25 mL of acidic drink (Coca-Cola) for 10 minutes each day up to 15 days. The microhardness of each sample was measured using a Vickers diamond intender. These values were matched with baseline, 7th day, and 15th day for final microhardness values. RESULTS: The mean surface microhardness of 61.13 ± 0.82 was shown by group I, which was slightly more than that in group II (59.65 ± 1.16) and group III (59.22 ± 1.30). Analysis of covariance did not show any statistically significant difference between the groups. The samples in group III showed the highest reduction in surface microhardness value after immersion into acidic drink, followed by group II and group I on 7th day and 15th day. A statistically significant difference (p < 0.001) was found on 7th day. CONCLUSION: The present study concludes that the esthetic restorative material-nanohybrid ormocer-based composite-showed the finest behavior both before and after being dipped in the acidic drink followed next by glasiosite compomer and nanoceramic composite. CLINICAL SIGNIFICANCE: The various esthetic restorative materials with different physical characteristics and colors are marketed in numerous ways. Nevertheless, all dental restorative materials show surface degradation under acidic conditions over a period of time. So, it helps to know the surface microhardness changes of various esthetic restorative materials upon repeated exposure to acidic beverages.

Effects of different pediatric drugs and toothbrushing on color change of restorative materials used in pediatric dentistry.

OBJECTIVE: The purpose of this study was to evaluate the effects of different pediatric drugs and toothbrushing on color changes of restorative materials used in pediatric dentistry. MATERIALS AND METHODS: Sixty specimens were prepared from each of three restorative materials (compomer [Dyract XP], glass hybrid [Equia Forte], and glass carbomer [GCP Glass Fill]). Specimens were divided into six solution groups (n = 10) and immersed in five different pediatric drugs (antibiotic, analgesic, common cold syrup, cough syrup, and an iron and vitamin formula) and distilled water. Two subgroups (brushed and unbrushed) were established for each group (n = 5). Specimens were agitated for 1 min every 8 h over 2 weeks. Color changes [CIEDE2000 (ΔE00)] were calculated at baseline, 7, and 14 days. Data were subjected to 4-factor mixed-design ANOVA using a general linear model procedure for repeated measurements. RESULTS: After 14 days, the highest ΔE00was found in the compomer/non-brushing group immersed in iron and vitamin formula (5.6 ± 0.27), and the lowest was in glass hybrid/brushing group immersed in distilled water (0.59 ± 0.8) pairwise. ΔE00values were significantly greater for compomer than for glass hybrid or glass carbomer (P < 0.05). There were statistically significant differences between the brushing and non-brushing groups for all tested solutions on the compomer specimens (except antibiotic) and glass hybrid specimens (except antibiotic and cough syrup). The Δ00 values in brushing groups were significantly lower statistically than in non-brushing groups (P < 0.05). CONCLUSIONS: Toothbrushing dramatically affected the color stability of the aesthetic restorative materials. The content of pediatric drugs is also an important factor for color change. Glass hybrids and glass carbomers used with their surface sealants appeared to be more resistant to staining from pediatric drug formulations than compomers.

Glass carbomer and compomer for ART restorations: 3-year results of a randomized clinical trial.

OBJECTIVE: To evaluate the survival of atraumatic restorative treatment (ART) restorations using high viscosity glass ionomer cement (GIC), compomer (COM), and glass carbomer (CAR) for occlusal and occlusoproximal cavitated dentin caries lesions in primary molars. METHODS: A total of 568 4-7-year-old children (287 occlusoproximal and 281 occlusal cavities) were selected in Barueri, Brazil. The patients were randomly allocated in three groups: GIC, COM, and CAR. All treatments were performed on school setting following ART premises. Evaluations were performed after 2, 6, 12, 18, 24, and 36 months. Restoration survival was evaluated using Kaplan-Meier survival analysis and log-rank test, while Cox regression analysis was used for testing association with clinical factors (α = 5%). RESULTS: The overall survival rate after 3 years of occlusal ART restorations was 73% (GIC = 83%; COM = 78%; CAR = 62%) and 49% for occlusoproximal ART restorations (GIC = 56%; COM = 56%; CAR = 36%). CAR restorations were less successful than GIC and COM for both occlusal and occlusoproximal restorations (p < 0.05). No difference was found between GIC and COM (p > 0.05). CONCLUSIONS: GIC and compomer are clinically more successful than CAR for occlusal and occlusoproximal restorations in primary molars. CLINICAL SIGNIFICANCE: Both compomer and high viscosity glass ionomer cement are suitable materials for ART in primary molars. However, glass carbomer cement should not be used for ART (#NCT02217098).

The evaluation of microleakage and fluoride release of different types of glass ionomer cements.

BACKGROUND: The aim of this study was to evaluate six different glass ionomer cement (GIC)-based restorative materials through comparisons of microleakage and fluoride release. MATERIALS AND METHODS: For microleakage, 30 teeth were randomly separated into 6 groups of 5: Group 1 (Dyract: compomer), Group 2 (Freedom: compomer), Group 3 (Equia: high-viscosity glass ionomer cements), Group 4 (Fuji IX: resin-modified glass ionomer cement), Group 5 (Ketac Molar: traditional glass ionomer cement [TGIC]) and Group 6 (Voco: TGIC). For fluoride release of six different GIC-based restorative materials, standard samples were prepared of 4 mm thickness and 7 mm diameter. A total of 60 samples were obtained as 10 samples from each group. The analyses were made using a Thermo Orion 720 A+ ionometer with the Orion fluoride electrode. At the end of 24 h, 72 h, 7 days, 14 days, and 30 days, the electrode was placed into the dish containing the sample, distilled water, and TISAB II; a reading was taken; and the value shown on the screen was recorded. RESULTS: For microleakage, a statistically significant difference was determined between the groups in respect of the occlusal variable (P < 0.05), no statistically significant gingival variable (P > 0.05). About fluoride release: According to the repeated measures variance analysis results, the difference between the groups, and between the time-group interaction and according to time, was found to be statistically significant (P < 0.05). CONCLUSIONS: In terms of microleakage, it was concluded that all materials could be used in clinical applications. The Equia high-viscosity glass ionomer cements (HVGIC) was determined to be the material with the highest fluoride release value.

Adhesives for fixed orthodontic brackets.

BACKGROUND: 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. OBJECTIVES: To evaluate the effects of different orthodontic adhesives for bonding. SEARCH METHODS: 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. SELECTION CRITERIA: 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 COLLECTION AND ANALYSIS: 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. MAIN RESULTS: 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. AUTHORS' CONCLUSIONS: There is no clear evidence on which to make a clinical decision of the type of orthodontic adhesive to use.

Hydrogen peroxide bleaching induces changes in the physical properties of dental restorative materials: Effects of study protocols.

OBJECTIVE: The purpose of this study was to evaluate the influence of study protocols on the effects of bleaching on the surface roughness, substance loss, flexural strength (FS), flexural modulus (FM), Weibull parameters, and color of 7 restorative materials. MATERIALS AND METHODS: The test materials included 4 composite resins, 1 glass-ionomer cement, 1 dental ceramic, and 1 polyacid-modified composite. The specimens were randomly divided into 4 groups (n = 20) according to different study protocols: a bleaching group at 25°C (group 25B), a bleaching group at 37°C (group 37B), a control group at 25°C (group 25C), and a control group at 37°C (group 37C). The specimens in the bleaching group were treated with 40% hydrogen peroxide for 80 min at the respective environmental temperatures. The surface roughness, substance loss, FS, FM, and color of the specimens were measured before and after treatment. FS data were also subjected to Weibull analysis, which was used to estimate of the Weibull modulus (m) and the characteristic strength (σ0 ). RESULTS: Surface roughness increased and significant color changes were observed for all tested specimens after bleaching treatment, except for the ceramic. After bleaching at 37°C, the polyacid-modified composite showed significantly reduced FS, FM, m, and σ0 values in comparison to the control specimens stored at 37°C in whole saliva. Significant differences were also found between the 37B and 25B polyacid-modified composite groups in terms of surface roughness, FS, m, σ0 , and color changes. CONCLUSIONS: Varying effects of bleaching on the physical properties of dental restorative materials were observed, and the influences of the study protocols on bleaching effects were found to be material-dependent. CLINICAL SIGNIFICANCE: The influence of study protocols on the effects of bleaching on the surface roughness, flexural properties, and color of dental restorative materials are material-dependent and should be considered when evaluating the effects of bleaching on dental restorative materials.

Compomers Reinforced with Bioactive Glass and Hydroxyapatite Particles.

PURPOSE: To understand the effect of the addition of hydroxyapatite (HA) and bioactive glass (BAG) to compomer restorative materials on the remineralisation capacity of the material. MATERIALS AND METHODS: 1%, 2%, 3% and 4% w/w HA and BAG particles were added mechanically to the compomers. To examine the resistance to demineralisation, Class V cavities were prepared in extracted teeth and restored with experimental filling materials. Demineralised lesions were created in 72 enamel samples. Vickers microhardness measurements of samples were performed at three different areas including the margin of the restoration, the varnish-protected enamel and the exposed enamel areas. Measurements performed on protected enamel were used as reference enamel values for each group. SEM was used to evaluate the surface texture of the specimens. The statistical analyses were performed by one-way ANOVA, Tukey's HDS and paired-samples t-tests. RESULTS: BAG and HA groups revealed higher microhardness values at the exposed enamel and exposed marginal enamel than did the control group (p = 0.001). 3% and 4% HA and BAG groups produced higher microhardness values than did 1% modified groups on exposed enamel (p = 0.001). 4% HA group revealed the highest microhardness values on marginal exposed enamel (p = 0.001). 2%, 3%, 4% and HA, as well as 3% and 4% BAG groups showed higher microhardness values than did the control group on marginal exposed enamel at 20 µm depth (p = 0.001). SEM images revealed that HA and BAG particles were not distributed homogeneously and the particles seemed to be grouped in the matrix. CONCLUSIONS: Within the limits of this study, the addition of the BAG and HA into compomers improved the demineralisation resistance properties of enamel, depending on the amount of additive.

Microtensile Bond Strength of Polyacid-modified Composite Resin to Irradiated Primary Molars.

AIM: This study evaluated the influence of various doses of radiotherapy on the microtensile bond strength (pTBS) of compomer resin to dentin and enamel in primary molars. MATERIALS AND METHODS: Thirty-five intact primary molars were collected and divided into seven groups. Teeth were irradiated with doses from 10 to 60 Gy, except for the control group. Compomer restorations were performed, and enamel-compomer resin beams and dentin-compomer resin beams were tested at a crosshead speed of 1 mm/min. RESULTS: No statistically significant difference was found between the irradiated tooth enamel and the control group (F = 1.1468; p = 0.194). However, statistically significant differences were evident among the dentin groups (F = 11.050; p < 0.001). CONCLUSION: Radiation may not cause a significant difference in the pTBS of compomer resin to primary tooth enamel, but appears to dose dependently decrease its bond strength to primary tooth dentin. CLINICAL SIGNIFICANCE: Radiotherapy may affect the success rate of compomer fillings in primary teeth, especially in deeper cavities with exposed dentin.

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

AIM: Using AutoCAD, we examined the microleakage of dye at the edges of primary-teeth restorations using three glass ionomer-based restorative materials. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSIONS: Polyacid-modified composite resin may be a useful restorative material in primary teeth in terms of minimizing microleakage.