An experimental teeth bleaching agent containing casein phosphopeptide-amorphous calcium phosphate.

OBJECTIVES: This study was aimed to obtain an experimental bleaching agent by adding casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) in order to eliminate the mineral loss on the tooth surface after bleaching and to evaluate the bleaching effectiveness. MATERIALS AND METHODS: In this study, experimental bleaching agents containing 1%, 3% CPP-ACP and without CPP-ACP were obtained. Bleaching effectiveness (color change), the effect of bleaching agents on mineral content (energy dispersive x-ray spectroscopy), surface morphology (scanning electron microscope), and surface hardness of enamel (Vicker's microhardness) before and after bleaching were evaluated. The obtained data were statistically analyzed. RESULTS: When the bleaching levels of the groups were compared, no statistically significant difference was observed between the control and 1% CPP-ACP groups (p > 0.05) while the addition of 3% CPP-ACP decreased significantly the effectiveness of the bleaching agent (p < 0.05). When the effects of experimental bleaching agents on surface hardness were examined, while the enamel surface hardness decreased statistically significantly after application in the control group (p < 0.05), no statistically significant change was observed in surface hardness after the application of 1% CPP-ACP containing bleaching agent (p > 0.05). However, a statistically significant increase was observed in surface hardness after the application of 3% CPP-ACP containing bleaching agent (p < 0.05). When the Ca and P ratio of the groups were compared, no statistically significant difference was observed between the control and 1% CPP-ACP groups (p > 0.05), while they increased significantly in 3% CPP-ACP group (p < 0.05). CONCLUSIONS: The addition of 1% CPP-ACP to the bleaching agent had positive effects on the mineral content and surface hardness of the enamel, and did not negatively affect the whitening effectiveness. CLINICAL SIGNIFICANCE: Adding CPP-ACP to the bleaching agent at appropriate concentrations can eliminate possible negative effects without compromising the effectiveness of the bleaching agent.

A randomized clinical study evaluating the 30-month clinical performance of class II indirect restorations in endodontically treated teeth using ceramic, hybrid, and composite computer-aided design/computer-aided production blocks.

Context Background: In the literature, the information about which indirect material is the most appropriate for the restoration of endodontically treated teeth is insufficient. Therefore, studies evaluating the clinical performance of root canal-treated teeth will shed light on this issue for clinicians. Aim: This clinical study aimed to evaluate the clinical performances of class II indirect restorations using ceramic, hybrid, and composite blocks to endodontically treated teeth. Materials and Methods: A total of 60 indirect class II restorations were performed in 51 patients using Cerasmart (GC Dental Products Europe, Leuven, Belgium) composite, IPS e.max computer-aided design CAD (Ivoclar Vivadent, Schaan, Liechtenstein) ceramic, and Vita Enamic (Vita Zahnfabrik, Bad Sackingen, Germany) hybrid blocks. All the restored teeth had root canal treatment. The restorations were evaluated using modified FDI criteria for 30 months. Statistical Analysis Used: The data were analyzed using Kruskal-Wallis analysis and Friedman two-way analysis of variance. Results: A total of 53 restorations of the 60 restorations could be followed up at the end of 30 months. No statistically significant difference was observed between the groups after 30 months in terms of all criteria evaluated (P > 0.05). Conclusion: Composite, ceramic, and hybrid blocks showed successful clinical performance in endodontically treated posterior teeth with large material loss.

The effect of propolis on the bond strength of composite resin to enamel after intracoronal bleaching with different bleaching agents.

This study evaluated the effect of propolis as an antioxidant agent on bond strength to enamel after intracoronal bleaching. A total of 160 incisors were endodontically treated. Sixteen teeth were served as control, and the remaining teeth were randomly divided into three main groups according to the bleaching agent used; group 1: Sodium perborate (SP); group 2: Carbamide peroxide (CP); group 3: Hydrogen peroxide (HP). After bleaching, the samples were divided into three subgroups; subgroup A: no antioxidant agent application, subgroup B: sodium ascorbate (SA), subgroup C: propolis (PP). After the antioxidant agents application, the sample's surfaces were washed and dried. After adhesive application, composite resin cylinders were applied to enamel surfaces using tygon tubes and a shear bond strength test was performed. The use of PP significantly decreased the bond strength of composite resin to the enamel (p < 0.05). Using propolis as an antioxidant agent adversely affects the bond strength to enamel after intracoronal bleaching.

Evaluation of six different one-step universal adhesive systems in terms of dentin bond strength, adhesive interface characterization, surface tension, contact angle, degree of conversion and solvent evaporation after immediate and delayed use.

OBJECTIVES: In this study, it was aimed to investigate the effects of different waiting periods on resin-dentin bond strength (BS), degree of conversion (DC), contact angle (CA), surface tension (ST), solvent evaporation (weight loss) and the characteristics of adhesive interfaces of the current six universal adhesive resins (ARs). MATERIALS AND METHODS: A total of 216 caries-free human lower third molar teeth were used. Composite resin restorations were performed by applying six universal ARs in etch-and-rinse and self-etch mode on standardized dentin surfaces after 0, 5, and 30 min waiting time. Then, a micro-shear BS test, SEM examination and characterization of the adhesive interface were performed. In addition, DC, CA, ST, solvent evaporation of all tested ARs were evaluated. RESULTS: The obtained data were statistically anaIyzed. The tested ARs did not show any statistical difference between 0 and 5 min evaluations in all parameters evaluated except for weight loss (p > 0.05). While the weight loss, ST and CA of all ARs increased in 30 min (p < 0.05), the BS, DC, thickness of the adhesive layer and the hybrid layer, resin tag length and number of resin tags varied according to the ARs used. When the ARs were used in etch-and-rinse mode, all the parameters evaluated also varied according to the AR used. Higher adhesive layer thickness and lower hybrid layer thickness were found in the self-etch mode (p < 0.05). CONCLUSIONS: All of the adhesives tested can be safely used up to 30 min. This could also prevent economical loss caused by waste adhesive material. CLINICAL SIGNIFICANCE: It is important to know how the bond strength, degree of conversion, adhesion, contact angle and surface tension properties of the adhesive resin waiting in the dispensing cup for a long time during clinical use are affected to make ideal restorations.

Evaluation of drug release, monomer conversion and surface properties of resin composites containing chlorhexidine-loaded mesoporous and nonporous hydroxyapatite nanocarriers.

The aim of this study was to evaluate drug release, degree of conversion (DC), and surface properties of resin composites containing chlorhexidine (CHX)-loaded mesoporous (mHAP) and nonporous hydroxyapatite (HAP) nanocarrier. CHX loaded mHAP and HAP, or CHX without nanocarrier was added into the resin composite in 1% and 5% concentrations. After characterization of experimental materials with XRD, EDX, FT-IR, and SEM, the CHX release on the 1st, 7th, 30th, and 120th days were evaluated by UV-vis spectroscopy. DC, surface roughness, and surface hardness of the samples were also evaluated. The data was statistically analyzed. While mHAP groups released significantly higher CHX on the 30th day (p < .05), there was no statistically significant difference between the HAP and mHAP groups on the 120th day (p > .05). DCs of all groups were similar (p > .05). While mHAP and HAP groups containing 5% CHX showed significantly higher roughness than the other groups (p < .05), no statistically significant difference was observed between the other groups (p > .05). The 1% and 5% CHX groups without nanocarrier showed significantly lower surface hardness (p < .05). However, no statistically significant difference was observed between the other groups in terms of surface hardness (p > .05). A controlled CHX release was achieved by mHAP and HAP nanocarriers for 120 days. The nanocarrier addition up to 5% did not negatively affect the DC and the surface hardness which is one of the surface properties of the resin composites. Although the addition of 5% nanocarrier to the resin composite increased the surface roughness, while adding 1% of these nanocarriers did not change.

Effect of different coronal restorations on the fracture resistance of teeth with simulated regenerative endodontic treatment: An in vitro study.

This study investigated the effect of different coronal restorations on the fracture resistance (FR) of immature teeth with simulated regenerative endodontic treatment. A total of 120 lower premolars were divided into eight groups. Except for negative control, the root canals were instrumented with rotary files and Peeso reamers. Fifteen instrumented teeth were acted as positive control (unrestorated). In the remaining 90 teeth, regenerative endodontic treatment procedures were performed. Ninety teeth were randomly divided into 6 groups according to coronal restoration type; Filtek Z550, Filtek Bulk fill Restorative (FBR), SDR+Filtek Z550, EverX+Filtek Z550, Ribbond+FBR and Ribbond+SDR+Filtek Z550. After thermal ageing, the restorated teeth were subjected to vertical loading force. FR values was obtained as follows: Negative control > Ribbond+FBR = Ribbond+SDR+Filtek Z550 > Filtek Z550 = FBR =SDR+Filtek Z550 = EverX+Filtek Z550 > Positive control, (P < 0.05). The use of Ribbond in combination with composite resin enhanced the FR of teeth.

Discoloration Behavior of Resin Cements Containing Different Photoinitiators.

The purpose of this study was to evaluate the sorption, solubility, and color stability of amine-free conventional light-cure and dual-cure resin cements and an amine-containing self-adhesive dual-cure resin cement. Sixty specimens were prepared using a light-cure resin cement (Variolink Esthetic LC, Ivoclar Vivadent; VE-LC), a dual-cure resin cement (Variolink Esthetic DC, Ivoclar Vivadent; VE-DC), and a self-adhesive dual-cure resin cement (RelyX U200, 3M ESPE; RXU200). The water sorption and solubility were tested by immersing the specimens in distilled water for 7 days. Kruskal-Wallis test was applied to the data. ΔE values of 1-day and 7-day immersion in black tea were analyzed using one-way analysis of variance followed by Tukey honest significant difference test (n = 10). There was no statistically significant difference among the groups in terms of sorption and solubility. The mean ΔE of RXU200 for the 0/1 and 0/7 days were found to be significantly lower than that of VE-LC and VE-DC (P < .05). ΔE values of the VE-LC and VE-DC groups did not reveal statistical difference. It should be taken into account that discoloration of resin cements remains a problem even with amine-free products.

Effect of two different temperatures on resistance to cyclic fatigue of one Curve, EdgeFile, HyFlex CM and ProTaper next files.

This study compared the cyclic fatigue resistance (CFR) of three controlled memory (CM) nickel-titanium rotary files (One Curve, EdgeFile and HyFlex CM) in comparison with a file (ProTaper Next) made from M-wire nickel-titanium alloy at two different temperatures (room and intracanal) in an s-shaped canal. One hundred and sixty files were tested to determine the CFR of OneCurve, EdgeFile, HyFlex CM and ProTaper Next in an artificial canal at room and at intracanal temperature. The number of cycles to failure was recorded, and data were analysed. At both temperatures, ProTaper Next exhibited the lowest CFR compared with the other files (P < 0.05). At room temperature, there was no difference among the three CM files regarding CFR (P > 0.05). At intracanal temperature, OneCurve and EdgeFile exhibited more CFR than the HyFlex CM (P < 0.05). Testing at intracanal temperature caused a significant decrease in CFR of all tested files compared with testing at room temperature.

A randomized, prospective clinical study evaluating effectiveness of a bulk-fill composite resin, a conventional composite resin and a reinforced glass ionomer in Class II cavities: one-year results.

OBJECTIVES: 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. 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.

Efficacy of different endodontic irrigation protocols on shear bond strength to coronal dentin.

AIM: The purpose of this study was to evaluate the effect of etidronic acid on bond strength to coronal dentin. MATERIALS AND METHODS: A total of 75 human mandibular molars were sectioned 3 mm below the occlusal surface and then randomly divided into five groups according to irrigation solution used (n = 15): Group 1: 5 ml 2.5% sodium hypochlorite (NaOCl) +5 ml distilled water; Group 2: 5 ml 2.5% NaOCl + 5 ml 17% ethylenediaminetetraacetic acid (EDTA); Group 3: 10 ml mixture of 5% NaOCl and 18% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP); Group 4: 5 ml mixture of 5% NaOCl and 18% HEBP + 5 ml 17% EDTA; and Group 5: 5 ml mixture of 5% NaOCl and 18% HEBP + 5 ml distilled water. Thereafter, Clearfil SE bond was applied to the dentin surfaces and then, composite build-ups were created using Tygon tubes for the microshear bond strength test. Data were analyzed using the one-way analysis of variance and Tukey test. RESULTS: When compared to Groups 3, 4, and 5, Groups 1 and 2 showed significantly higher bond strength values (P < 0.05). However, there was no statistically significant difference between Groups 1 and 2 and between Groups 3, 4, and 5 (P > 0.05). CONCLUSION: HEBP adversely affected the bond strength of the tested adhesive to coronal dentin.

The Effect of Different Cavity Designs and Temporary Filling Materials on the Fracture Resistance of Upper Premolars.

INTRODUCTION: The aim of this study was to compare the fracture resistance of upper premolars undergoing root canal treatment that had been temporarily restored with 4 different temporary filling materials. METHODS: This study was based on 120 extracted upper premolars. Eight teeth were left intact and served as the negative control group. Mesio-occluso-distal cavities with 2 different designs were prepared for the rest of the teeth (for group 1 a width of one third of the intercuspal distance and for group 2 a width of two thirds of the intercuspal distance). Then, the endodontic access cavities were prepared, and the root canals instrumented with Revo-S rotary files (MicroMega, Besancon, France). Thereafter, a total of 16 teeth consisting of 8 each from group 1 and group 2 served as the positive control group and did not have any temporary filling material. The teeth were randomly divided into 4 subgroups (n = 12) according to the temporary filling material: Cavit G (3M ESPE, St Paul, MN), Coltosol F (Coltène/Whaledent AG, Altstätten, Switzerland), Intermediate Restorative Material (Dentsply Sirona, Konstanz, Germany), or DiaTemp (DiaDent Europe BV, Almere, Netherlands). Each specimen was then subjected to a fracture resistance test using a universal testing machine until the fracture occurred. The force required to fracture each specimen was recorded, and the data were statistically analyzed. RESULTS: The negative control group showed the highest fracture resistance values compared with the other groups, whereas the positive control groups showed the lowest fracture resistance values. There were no statistically significant differences in the fracture resistance of upper premolar teeth undergoing root canal treatment among Cavit G, Intermediate Restorative Material, Coltosol F, and DiaTemp, regardless of the cavity width (P > .05). CONCLUSIONS: The cavity design was found to be an effective factor on the fracture resistance of upper premolar teeth undergoing root canal treatment. The temporary filling materials tested did not affect the fracture resistance.

A randomized, prospective clinical study evaluating effectiveness of a bulk-fill composite resin, a conventional composite resin and a reinforced glass ionomer in Class II cavities: one-year results

Abstract 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.

Bonding performance of universal adhesives on composite repairs, with or without silane application.

AIM: This study aims to investigate the adhesive performance of three different universal adhesives to repair aged composite restorations, with or without the application of silane. MATERIALS AND METHODS: A hundred and twenty resin composite samples were prepared, aged and randomly divided into 6 main Groups (single bond universal [SBU], All-Bond Universal [ABU], Futurabond U, Clearfil Tri-S Bond, Single Bond 2, and Clearfil SE Bond) and 2 subgroups (with or without silane). A microhybrid composite resin was placed on the aged composite surfaces and light cured. After a micro-shear bonding test, the fracture surfaces were examined under the scanning electron microscopy. Statistical analysis was performed using two-way ANOVA and Tukey's post hoc tests. RESULTS: Among all the universal adhesives, SBU showed the highest bond strength values compared to the other two universal adhesives when used with and without silane (P > 0.05). Between ABU and Futurabond U, no significant difference was observed with silane (P > 0.05) and without silane (P > 0.05). Among conventional adhesives, there was no statistically significant difference (P > 0.05) both with and without silane. CONCLUSION: Within the limitations of this study, while SBU can be safely used with and without the application of silane, Futurabond U cannot be used without silane.

Micro-shear bond strength of universal adhesives used for amalgam repair with or without Alloy Primer.

AIM: The aim of this study was to investigate the adhesive performance of three different universal adhesives to repair aged amalgam by composite resins with or without Alloy Primer. MATERIALS AND METHODS: Sixty amalgam samples were prepared, aged, and randomly divided into 12 main groups according to adhesive procedures used. Composite buildups were placed on amalgam surfaces. After micro-shear bonding test, the fracture surfaces were examined under the scanning electron microscopy statistical analysis was performed using two-way analysis of variance and Tukey's post hoc tests. RESULTS: Without use of Alloy Primer, all of the universal adhesives provided similar bond strength values with conventional adhesives (P > 0.05); however, an Alloy Primer significantly increased the bond strength values of universal adhesives (P < 0.05). No significant difference in bond strength values was noted for conventional adhesives with or without Alloy Primer (P > 0.05) except for Clearfil SE Bond (P < 0.05). CONCLUSIONS: Within the limitations of this study, it can be concluded; using Alloy Primer before universal adhesives increased the bond strength significantly.