Influence of residues from bioceramic sealer on the bond interface with universal adhesive in different application modes.

This study evaluated the effect on adhesive layer thickness, bond strength, and adhesive failure pattern of the application of universal adhesive (Scotchbond Universal) using either manual or rotary brush in dentin previously impregnated with bioceramic sealer (Sealer Plus BC) using a manual brush, at 24 h and 1 year. Eighty-eight bovine crowns were divided into four groups (n = 22) according to the intervention: (i) use of bioceramic sealer and adhesive application using manual brush, (ii) use of bioceramic sealer and adhesive application using rotary brush, (iii) use of resin sealer and adhesive application using manual brush, and (iv) use of resin sealer and adhesive application using rotary brush. Subsequently, specimens were restored with a composite resin (Filtek Z-250). Adhesive layer thickness was evaluated using confocal microscopy. Bond strength was assessed using the microtensile bond strength test, and adhesive failure pattern was evaluated under a stereomicroscope. Data were analyzed using two-way ANOVA/Tukey tests. Specimens where a rotary brush had been used exhibited lower adhesive layer thickness. Specimens treated with resin sealer and using a manual brush showed lower bond strength values and a higher occurrence of adhesive failures at 24 h and 1 year than specimens treated with bioceramic sealer and using rotary brush for adhesive application.

Influence of luting strategies on dentin bond performance of self-adhesive resin luting cement in combination with a universal adhesive.

OBJECTIVES: This study aimed to evaluate the dentin bond performance of various resin luting cement (RLC) systems combined with universal adhesives in different luting strategies. MATERIALS AND METHODS: Three self-adhesive resin luting cements (SRLCs) were used with universal adhesives as primers. Twelve specimens per group were prepared to measure shear bond strength (SBS) under distinct luting strategies in etch-&-rinse and self-etch modes. Regarding luting strategies, the bonded specimens were categorized into four groups based on tooth primer application and the curing mode of the SRLC paste: (i) with light irradiation of the tooth primer (wL) + dual-cure mode (DC) of the SRLC paste, (ii) wL + self-cure mode (SC) of the SRLC paste, (iii) without light irradiation of the tooth primer (woL) + DC mode of the SRLC paste, and (iv) woL + SC mode of the SRLC paste. Specimens were also subjected to different storage conditions: 24 h in water (baseline condition) and 10,000 cycles of thermal cycling. RESULTS: Luting strategy, storage condition, and SRLC system type significantly influenced dentin SBS values in both etching modes. Notably, certain SRLCs exhibited significantly higher dentin SBS when the primer was light-irradiated compared with no primer irradiation. CONCLUSION: Most SRLCs demonstrated higher dentin bond strength with light-irradiated primers, suggesting potential enhancement of dentin bond performance via primer light irradiation.

Shear bond strength of universal adhesives to human enamel and dentin.

OBJECTIVE: The composition of universal adhesives is highly diverse. The purpose of this in vitro study was to compare the shear bond strength of a composite with five different universal adhesives to human enamel and dentin. MATERIALS AND METHODS: The shear bond strength of a composite (G-aenial Universal Injectable) to human enamel and dentin was tested in selective enamel etching mode before and after thermocyclic aging (10,000 cycles) using five different universal adhesive systems (Adhese Universal VivaPen, Clearfil Universal Bond Quick, G-Premio Bond, Prime&Bond active, and Scotchbond Universal Plus). Two-bottle systems (OptiBond FL and G2-Bond Universal) were used as control. Scanning electron microscopy was conducted of the bonding interface. RESULTS: Significant differences in shear bond strength values were found among the five evaluated universal adhesives. Lowest shear bond strength values were observed for 2-hydroxyethylmethacrylate (HEMA)-free systems. Thermocyclic aging did not significantly reduce shear bond strength values indicating that the initial bond remains stable. CONCLUSIONS: The clinical use of universal adhesives Adhese Universal VivaPen, Clearfil Universal Bond Quick, and Scotchbond Universal Plus can be encouraged as they provided comparable or even better shear bond strength values than the two-bottle controls. CLINICAL SIGNIFICANCE: Universal adhesives that were developed for the same indication and approved for clinical use demonstrated variety in shear bond strength values. When applied in the selective enamel etching mode, a stable bond can be expected from adhesives containing HEMA and monomers with phosphate groups.

Microtensile Bond Strength of Self-Etch Adhesives on Dentin Treated with Chlorhexidine.

AIM: To evaluate the microtensile bond strength of self-etching adhesive systems in dentin treated with 2% chlorhexidine digluconate (CHX). MATERIALS AND METHODS: The occlusal surfaces of 20 human molars were removed and divided into eight groups: 1A, Clearfil SE adhesive (SE) with self-etching technique (TS); 1B, SE with TS and previous application of CHX; 2A, Scotchbond Universal (SBU) adhesive with TS; 2B, SBU adhesive with TS and previous application of CHX; 1C, SE with total-etching technique (TT); 1D, SE with TT and previous application of CHX; 2C, SBU with TT; 2D SBU with TT and previous application of CHX. Composite resin (5mm) was applied on the hybridized surface. Samples were subjected to microtensile test and evaluated on Scanning Electron Microscope (SEM) and with energy-dispersive X-ray (EDX). RESULTS: Low values of bond strength were observed in groups 1A (39,77±11,56) and 2A (40,84±12,49) comparing with 1B (22,86±5,18) and 2B (27,02±5,58). TS group presented adhesive type remover fracture while TT groups presented cohesive at the top of hybrid layer. EDX revealed the presence of CHX crystals for TS, which was not found in the TT. CONCLUSION: The previous application of chlorhexidine on dentin decreased the bond strength of adhesive systems on self-etching technique.

Effect of irradiance and exposure time on the adhesive properties of universal adhesives after 2 years of storage.

OBJECTIVE: This study aims to evaluate the effects of exposure time and irradiance on the dentin bonding properties (microtensile bond strength (µTBS) and nanoleakage (NL)) of the Clearfil Universal Bond Quick (CUQ) adhesive and Scotchbond Universal Adhesive (SBU) immediately and after 2 years of water storage. MATERIAL AND METHODS: Hence, 128 human molars were randomly assigned to 16 groups based on adhesive strategy, irradiance/exposure times, and storage time for each universal adhesive tested. The adhesives were applied using the etch-and-rinse and self-etch strategies and were light-cured using four different irradiance/exposure times: 1400 mW/cm2 for 5 s (1400 × 5), 1400 mW/cm2 for 10 s (1400 × 10), 3200 mW/cm2 for 5 s (3200 × 5), and 3200 mW/cm2 for 10 s (3200 × 10). Then, each sample was restored and sectioned into a resin-dentin bonded stick to be tested for µTBS and NL (immediately and after 2 years of water storage). The mean µTBS and NL of all resin-dentin bonded sticks from the same hemi-tooth (factor time) were statistically analyzed using a three-way ANOVA and Tukey's test (a = 0.05). RESULTS: Despite a significant decrease in the µTBS values for all groups after 2 years of water storage, the 3200 × 5 group showed higher µTBS values, whereas the 3200 × 10 group showed lower µTBS values for both universal adhesives tested. Although a significant increase in the NL values was observed for all groups after 2 years of water storage, the 3200 × 10 group showed higher NL values than the other groups (p < 0.001). CONCLUSION: Results indicate that light-curing the adhesive layer with 14-16 J/cm2 led to an improvement in the stability of the resin-dentin adhesive interface. A longer exposure time (10 s) coupled with a higher irradiance (3200 mW/cm2) resulted in a greater degree of degradation of the adhesive interface. CLINICAL SIGNIFICANCE: To guarantee better stability of the adhesive interface, clinicians could be preferred a light-cured universal adhesive layer with 14-16 J/cm2. Higher irradiances should be avoided.

Dentin bond strength and antimicrobial activities of universal adhesives containing silver nanoparticles synthesized with Rosa canina extract.

OBJECTIVE: The purpose in the study was to evaluate the effect of biogenic silver nanoparticles (Ag NPs) synthesized by the green synthesis method on dentin bond strength in three different universal adhesives and investigate their antibiofilm activity against Streptococcus mutans (S. mutans). MATERIALS AND METHODS: Three different universal adhesives (single bond universal, all-bond universal, and clearfil universal) were used in this study. Ag NPs were synthesized using rose hip (Rosa canina) extract as a reducing and stabilizing agent and they were characterized with STEM, UV-vis spectrophotometer, DLS, and zeta potential. Ag NPs were added to the adhesive resins at a rate of 0.05% (w/w), and their homogeneous distribution in the adhesive was determined using EDX spectrometry. Samples in all groups were tested at baseline-after 5000 and 10,000 thermal cycles. Adhesive composite discs were used for the live/dead analysis of S. mutans, MTT metabolic activity test, lactic acid production, and determination of colony-forming unit (CFU) values (n = 3). Ninety extracted caries-free human third molars were used to determine microtensile bond strength (µTBS) (n = 10). After the universal adhesive was applied to the dentin surface, composite resin (Z550 XT, 3 M ESPE, USA) was placed and sections were taken to form a composite-dentin stick of 1 mm × 1 mm wideness and 8-mm length. The sticks were broken at a rate of 1 mm/min under uniaxial tension in a universal testing machine, and the failure modes were determined by SEM. One-way analysis of variance (ANOVA) for antibacterial tests and two-way analysis of variance for µTBS tests were performed (p < 0.05). RESULTS: All universal adhesive groups containing Ag NPs showed higher antibacterial activity than control groups without Ag NPs (p < 0.05). There was a statistically significant difference in the live/dead assay analysis, MTT metabolic activity test, lactic acid production, and CFU values in the thermal cycled Ag NPs groups (p < 0.05). Antibacterial activity decreased in groups containing Ag NPs subjected to 10,000 thermal cycles. The highest lactic acid production 11.06 (± 0.629) and CFUs 7.61 (± 0.304), live bacteria 31.13 (± 0.466), and S. mutans MTT metabolic activity 0.29 (± 0.376) at AU (All-Bond Universal-Ag NPs) 10,000 thermal cycles group. There was no difference in µTBS values between the initial and 5000 thermal cycle groups, there was a difference between the 10,000 thermal cycle groups. The CU (Clearfil Universal-Ag NPs) group subjected to 10,000 thermal cycles showed lower µTBS 11.1 (± 3.2). CONCLUSION: In conclusion, universal adhesives containing biogenic Ag NPs showed higher antibacterial activity than the control groups and did not reduce the µTBS. CLINICAL RELEVANCE: Antibacterial universal adhesives can contribute to restoration success in clinical applications by reducing residual bacteria and preventing secondary caries formation.

Effect of an additional bonding resin on the 5-year performance of a universal adhesive: a randomized clinical trial.

OBJECTIVES: To evaluate the effect of the application of an additional hydrophobic bonding resin on the clinical performance of a universal adhesive applied in etch-and-rinse (ER) or self-etch adhesive (SE) strategy in non-carious cervical lesions (NCCLs) after 5 years. MATERIALS AND METHODS: Scotchbond Universal Adhesive (3M Oral Care) was applied in 134 NCCLs of 39 subjects using different adhesion approaches: 3-step ER (3-ER), 2-step ER (2-ER), 2-step SE (2-SE), and 1-step SE (1-SE). Enamel and dentin were acid etched prior to application of the universal adhesive for the 3-ER and 2-ER groups. An extra layer of a hydrophobic bonding resin was applied for groups 3-ER and 2-SE. All lesions were restored with Filtek Supreme XTE resin composite (3M Oral Care). Restorations were evaluated at baseline and at 5 years using the modified USPHS criteria. Mann-Whitney U and Wilcoxon tests were performed, and the survival rates (retention/fracture) were analyzed using Kaplan-Meier and log-rank tests (p < 0.05). RESULTS: The recall rate was 66.7% at 5 years. The cumulative survival rate was 96.9% for 3-ER, 96.8% for 2-ER, 71.4% for 2-SE, and 81.3% for 1-SE strategies. The log-rank test was statistically significant (p = 0.006). Retention rates were 100% for both ER groups, 75% for 2-SE and 81.3% for 1-SE. At 5 years, 2- and 1-SE approaches showed similar retention rates, but lower than those for 3- and 2-ER. A significant decrease in retention rate was detected for 2-SE (p = 0.007) and 1-SE (p = 0.014) groups between baseline and 5 years. All groups, except 2-ER, showed an increase in marginal discoloration. For this parameter, significant differences were detected between 2-ER and 1-SE (p = 0.004). CONCLUSIONS: The addition of a hydrophobic bonding resin to the recommended application sequence of Scotchbond Universal Adhesive did not improve its clinical performance in NCCLs after 5 years. Higher retention rates were measured when this adhesive was applied in ER mode. TRIAL REGISTRATION: This manuscript is a 5-year follow-up of a randomized clinical trial that started in 2012 when there was no strong recommendation for registration in clinicaltrials.gov. The results after 36 months of clinical service were previously published in this journal.

Effect of adhesive strategy on resin cement bonding to dentin.

OBJECTIVE: The cement bonding strategy and the polymerization mode can influence the prognosis of indirect restorations. The microtensile bond strength (µTBS) and dentin endogenous enzymatic activity of a dual-cure resin cement (PV5) used in combination with two dentin surface conditioners (accelerator-enhancer primer, TP or universal adhesive, UA) were evaluated. MATERIALS AND METHODS: PV5 was used to lute composite overlays after dentin treatment with TP or UA. The resin cement was self-cured, SC (1 h at 37 °C) or dual-cured, DC (20 s light-cure followed by 15 min self-cure at 37°C). The µTBS test, fractographic analysis, and the in situ zymography evaluations were performed after 24 h (T0 ) or 1 yr (T12 ) of artificial storage. Data were statistically analyzed (α = 0.05). RESULTS: TP/DC obtained the highest adhesive strengths (45 ± 9 and 36.6 ± 8), while UA/SC (17 ± 8 and 11 ± 4) the lowest, both at T0 and T12 , respectively. DC resulted in superior bonding values than the SC, independent of the dentin surface treatment (p < 0.05). The type of adhesive, curing mode and aging influenced the gelatinolytic activity (p < 0.05). CONCLUSIONS: The dual-cure resin cement used in combination with its accelerator-enhancer primer showed superior bonding performances with respect to universal adhesive. Dual-curing the resin cement was determinant to enhance bonding capability over time, independent of the adhesive strategy. CLINICAL RELEVANCE: Clinicians must be aware to faithfully follow manufacturer's recommendation regarding the adhesive strategy suggested with the resin cement used.

Bond strength to different CAD/CAM lithium disilicate reinforced ceramics.

OBJECTIVE: To evaluate the microstructure and the influence of applying universal adhesive only versus universal adhesive with additional silane application on shear bond strength (SBS) to four different lithium disilicate ceramic (LDC) materials. MATERIAL AND METHODS: Specimens (n = 240, 1.5 mm thick) cut from four different CAD/CAM materials were polished and etched with 4.5% hydrofluoric (HF) acid according to manufacturers' instructions (20 s: IPS e.max CAD, n!ce; 30 s: Amber Mill, CEREC Tessera). For cementation, either universal adhesive only or silane + universal adhesive were applied before prefabricated composite cylinders were cemented using a dual-cure resin cement. SBS testing was performed either after 24 h or after 20,000 cycles thermocycling +2 months water storage. Surfaces were analyzed with stereomicroscope for failure mode and with scanning-electron microscopy for microstructure of the LDC. Statistical analysis of the data was performed with non-parametric tests at α = 0.001. RESULT: SBS values for non-aged specimens ranged from 29.08 to 17.87 MPa and for aged specimens from 22.24 to 3.01 MPa. SBS was significantly reduced when silane was omitted after aging, (p < 0.001). Failure mode was mostly mixed with some cohesive failures in the LDC. CONCLUSION: Bond strengths are highly affected by the CAD/CAM LDC and their microstructures. The application of silane after hydrofluoric etching is still essential to obtain long-term bonding, irrespective of the presence of silane in the universal adhesive. Water degradation can significantly affect long-term bonding to novel LDC. CLINICAL SIGNIFICANCE: When using a universal adhesive for bonding to LDC restorations, the best long-term bond is achieved if an additional application of silane precedes the universal adhesive.

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.

The effect of dentin surface pretreatment using dimethyl sulfoxide on the bond strength of a universal bonding agent to dentin.

BACKGROUND: This study aimed to evaluate the effect of dentin pretreatment by Dimethyl Sulfoxide (DMSO) on the bond strength and microleakage of a universal bonding agent to dentin. METHODS: Fifty-six dentinal discs (thickness = 2 mm) were obtained from the crowns of the human third molars. The disks were assigned into 4 groups and treated as follows; self-etch-control group: G-Premio universal adhesive was used in self-etch mode, total-etch-control: G-Premio universal adhesive was used in total-etch mode, self-etch-DMSO: Water-based DMSO (50% volume) was applied on the samples for 60 s followed by application of G-Premio universal adhesive in self-etch mode, and Total-etch-DMSO: The samples were etched, and then, water-based DMSO was applied on them for 60 s followed by the application of G-Premio universal adhesive in total-etch mode. Afterward, resin composite was placed on all samples and light-cured. The samples were kept in distilled water and subjected to 5000 thermal cycles. Microshear bond strength was measured using the universal testing machine and failure modes were analyzed using a stereomicroscope. Forty-eight human third molars were used for microleakage evaluation and a standardized class five cavity was prepared on the buccal surface of each tooth. The teeth were assigned into 4 groups and received aforementioned surface treatment and the cavities were filled with resin composite. After storing in water for 24 h, the samples were subjected to 5000 cycles of thermocycling and the microleakage level of the samples was evaluated using silver nitrate uptake at the bonded interface. Two-way ANOVA test was used to analyze the effect of bonding technique (self-etch/ total-etch) and DMSO pretreatment on the microshear bond strength and microleakage of G-Premio adhesive to dentin. RESULTS: Bonding technique had no effect on the bond strength values (p = 0.17) while DMSO pretreatment significantly decreased the microshear bond strength of the samples (p = 0.001). DMSO application increased microleakage significantly in total-etch (P-value = 0.02) while it had no effect in self-etch mode (P-value = 0.44). CONCLUSIONS: Pretreatment of dentin using 50% DMSO significantly reduced the bond strength of G-Premio Bond in both self-etch and total-etch modes. DMSO effect on microleakage depended on the etching technique; DMSO increased the microleakage level when the adhesive was used in total-etch mode while did not affect the microleakage in self-etch mode.

Surface topography and spectrophotometric assessment of white spot lesions restored with nano-hydroxyapatite-containing universal adhesive resin: an in-vitro study.

BACKGROUND: White spot lesion (WSL) is a main shortcoming accompanied by orthodontic treatment. It impairs the esthetic, surface hardness, and surface texture of enamel. So, this study was conducted to analyze the surface characteristics and color change of white spot lesions treated with nano-hydroxyapatite (nHA)-enriched universal adhesive resin. MATERIALS AND METHODS: Eighty sound human permanent molars crowns were sectioned into two halves, producing 160 specimens. 16 specimens were left untreated, and 144 specimens were artificially-demineralized to generate WSLs. The specimens were classified according to the treatment approach applied as follows: I; Sound enamel, Group II; artificially-created WSLs, Group III; ICON resin-restored WSLs, Group IV; Universal adhesive resin-restored WSLs, Group V; 0.5 wt% nHA-containing universal adhesive resin-restored WSLs, Group VI; 1 wt% nHA-containing universal adhesive resin- restored WSLs, and Group VII; 3 wt% nHA-containing universal adhesive resin-restored WSLs, Group VIII; 5 wt% nHA-containing universal adhesive resin-restored WSLs, Group IX; 7 wt% nHA-containing universal adhesive resin-restored WSLs, and Group X; 10 wt% nHA-containing universal adhesive resin-restored WSLs. Some surface characteristics and color changes were assessed. Data was collected and analyzed statistically using ANOVA and the Tukey test at p < 0.05. RESULTS: Surface microhardness of WSLs was significantly improved with all investigated ratios of nHA-containing universal adhesive (p < 0.0001), with the highest mean belonging to 10 wt% nHA-containing universal adhesive resin treated WSLs. All ratios of nHA-containing universal adhesive resin significantly reduced the surface roughness of WSLs (p < 0.0001). The investigated ratios of 1, 3, 5, 7, and 10 wt% nHA-containing universal adhesive resin treatment approach could mask the WSLs significantly (p < 0.0001). CONCLUSIONS: Nano-hydroxyapatite-containing universal adhesive is a promising contemporary approach for the management of WSLs, coupled both the remineralizing concept and the minimally invasive resin infiltration.

In vitro performance of an autocured universal adhesive system in bonding to dentin.

BACKGROUND: The successful integration of resin-based dental adhesives significantly impacts restorative dentistry, providing efficient and aesthetically pleasing caries treatments. Among various adhesives, one-step self-etching adhesives (1-SEAs) have gained popularity due to their simplicity and short application time. However, concerns have been raised regarding their bonding performance and marginal adaptation characteristics, which differ from two-step self-etching adhesives (2-SEAs) and three-step etch-and-rinse adhesives. Additionally, light-cured bonding materials may encounter challenges in deep cavities and inaccessible areas, necessitating extended light irradiation time. Autocured bonding materials are a potential solution, but limited comparative studies have been conducted on their performance. METHODS: In this in vitro study, we evaluated a new autocured universal bonding material (Bondmer Lightless 2) and compared the results with recent light-cured bonding materials. Microshear bond strength (µSBS) tests were performed on 25 human molars using five different combinations of adhesives and composite resins: Bondmer Lightless 2 with Estelite Bulk Fill Flow (BE group), Bondmer Lightless 2 with a prototype composite resin (BO group), Prime&Bond Universal with SDR flow + (PS group), Scotchbond Universal with Filtek Bulk Fill (SF group), and G-Premio Bond with Gracefil BulkFlo (GG group). The bond strengths and failure modes were assessed using a universal testing machine and scanning electron microscope (SEM), respectively. Marginal adaptation was evaluated using swept-source optical coherence tomography (SS-OCT) and confocal laser scanning microscopy (CLSM) on 40 sound bovine maxillary incisors. RESULTS: The µSBS test showed no significant differences in bond strength among the tested groups. Most failure modes were observed at the bond interface between the adhesive and the dentin. The autocured bonding material demonstrated significantly higher marginal adaptation (SI%) than PS, SF, and GG. The CLSM images corresponded with gaps observed in the SS-OCT images, indicating improved marginal sealing in the autocured group. CONCLUSIONS: The new autocured universal bonding material exhibited comparable bond strength to a conventional light-cured material while demonstrating a superior marginal adaptation level. This finding suggested that the autocured material could be a valuable alternative, especially when extended light irradiation would pose a challenge. Further clinical studies would be warranted to evaluate the performance of the autocured bonding material in actual restorative dental practice.

Evaluating the effect of poly (amidoamine) treated bioactive glass nanoparticle incorporated in universal adhesive on bonding to artificially induced caries affected dentin.

BACKGROUND: The purpose of this study was to evaluate remineralisation and its effect on microtensile bond-strength of artificially induced caries affected dentin (CAD) when treated with a commercial universal adhesive modified with poly(amidoamine) dendrimer (PAMAM) loaded mesoporous bioactive glass nanoparticles (A-PMBG). MATERIAL AND METHODS: Mesoporous bioactive glass nanoparticles (MBG) were synthesised using sol-gel process, where PAMAM was loaded (P-MBG) and added to commercial adhesive at different weight percentages (0.2, 0.5, 1 and 2 wt%). First, rheological properties of commercial and modified adhesives were evaluated. The effect of remineralization/hardness and microtensile bond-strength (MTBs) of those samples that mimicked the rheological properties of commercial adhesives were evaluated using Vickers hardness tester and universal testing machine respectively. Scanning-Electron microscope was used to visualize failed samples of MTBs and remineralization samples. Both evaluations were carried out at 1-,3 and 6-month intervals, samples being stored in stimulated salivary fluid during each time interval. RESULTS: Addition of nanoparticles altered the rheological properties. With increase in the weight percentage of nanoparticles in commercial adhesive, there was significant increase in degree of conversion, viscosity and sedimentation rate (p < 0.05). The 0.2 and 0.5 wgt% groups closely mimicked the properties of commercial adhesive and were evaluated for remineralization and MTBs. After 6 months, 0.2wgt% group showed increased MTBs (p < 0.05) and 0.5wgt% group increased remineralization/hardness (p < 0.05). CONCLUSION: The complex of PAMAM-MBG-Universal adhesive can remineralize the demineralised CAD thereby improving its bond-strength when evaluated for up to 6-months.

Evaluation of different decontamination procedures on bond strength to sound and caries affected dentin using "no-wait" universal adhesive.

BACKGROUND: Current study aimed to evaluate the effect of different decontamination procedures on micro-shear bond strength (µSBS) of sound (SoD) and caries-affected dentin (CAD) of two universal adhesives after blood-saliva contamination. METHODS: One hundred and eighty bovine anterior teeth were prepared and allocated into the respective groups according to tested dentin substrates [SoD, CAD], universal adhesives [Clearfil Bond Universal Quick (UBQ), All-Bond-Universal (ABU)], adhesive contamination stage [none, contamination before and after adhesives light-curing], and according to decontamination procedures [no decontamination, water rinsing, adhesive rebond, Ethylenediaminetetraacetic acid (ETDA) and chlorhexidine (CHX) application]. Universal adhesives were applied according to manufacturer instructions in self-etch (SE) bonding mode. Four composite microrods were built for each tooth. Specimens were kept in distilled water for 24 hours at 37°C before testing µSBS. Four-way ANOVA and Tukey HSD tests were used for data analysis. RESULTS: A statistically significant difference between contamination stages of both universal adhesives at different decontamination procedures for SoD and CAD. Highest µSBS was recorded for UBQ control group at SoD, while the least was recorded for light-cured ABU upon water rinsing decontamination procedure of CAD. CONCLUSIONS: Proper cavity isolation is mandatory to avoid possible contamination which can dramatically affect µSBS. CHX is a potent cavity decontaminant that can restore different dentin substrates bond strength. EDTA presents a promising substitute. UBQ adhesive showed better bonding performance than ABU to both dentin substrates. Application of regular cavity decontamination approaches is highly advised in daily practice to avoid possible detrimental effect of accidental cavity contamination.

The Influence of Chlorhexidine Gluconate Dentine Pre-Treatment on Adhesive Interface and Marginal Sealing.

Background and Objectives: The aim of this in vitro study was to evaluate the combined effect of a 2% chlorhexidine aqueous solution and a universal adhesive system applied in self-etch and etch-and-rinse strategies on the composite resin-dentin interface. Materials and Methods: Class V cavities were prepared on the facial and lingual surfaces of forty caries-free molars extracted for orthodontic reasons. The samples were randomly divided into two groups corresponding to the used etching protocol: I-etch-and-rinse; II-self-etch. In each tooth, one cavity was assigned for the control subgroups -IA (n = 20) and IIA (n = 20)-adhesive only, and the opposite cavity was pretreated with a 2% chlorhexidine solution-Gluco CHeX Cerkamed-subgroups IB (n = 20) and IIB (n = 20). Both sets of groups were restored using a universal adhesive system (Single Bond Universal Adhesive, 3M-ESPE) and a bulk-fill composite resin (Filtek One Bulk Fill Restorative, 3M-ESPE). The roots and the pulp tissue were then removed, and a needle connected to a perfusor with 100 mL saline solution was used for pulp pressure simulation with a hydrostatic pressure of 20 cm H2O. Cariogenic attack was simulated using a demineralizing solution for 3 days at a constant temperature of 25 °C. The teeth were then sectioned in a facial-lingual direction and the microleakages at the occlusal and cervical margins were registered and scored using an optical Carl-Zeiss AXIO Imager A1m microscope (Carl-Zeiss). The composite resin-dentin interface was analyzed using a SEM Vega Tescan LMH II. Statistical analysis was performed using the Kruskal-Wallis test with a significance level of p < 0.05. Results: Microleakage evaluation showed no significant differences among the study groups (p > 0.05). In subgroup IA, significant differences were recorded between occlusal and cervical margins (p < 0.05). Conclusions: Application of chlorhexidine on tooth substrate before using a universal bonding system in total etch or self-etch mode has no influence on the adhesive interface in the condition of cariogenic attack. The thickness of the adhesive resin layer seems to be less uniform when using chlorhexidine, but the morphological differences at the adhesive interface have no influence on the sealing capacity of the universal bonding system, regardless of the etching strategy.

Short-Term Comparison of Clinical Performance of Universal Adhesives with Self-Etch Mode in NCCL Restorations.

OBJECTIVES: To evaluate the clinical performance of universal adhesives with self-etch mode regarding their functional monomer and HEMA contents. METHODS: The study involved 27 patients (108 restorations) aged between 34 and 69 (mean age: 53.8). Each restoration contained one of four different universal adhesives applied in self-etch mode: G-Premio Bond (HEMA-free, MDP and 4-MET containing), Xeno Select (HEMA and MDP-free), Tetric-n-Bond Universal (HEMA and MDP-containing) and Clearfil Universal Bond Quick (HEMA, MDP and amide monomers containing). The restorations were evaluated according to the FDI criteria at baseline, 6, and 12 months. The data were statistically analyzed using Friedman's and Kruskal-Wallis tests for significance in each pair (p⟨0.05). RESULTS: After 12 months, one restoration was lost in each of the G-Premio Bond and Clearfil Bond Quick groups. The success rate was 96.3% for both adhesives and 100% for Xeno Select and Tetric-n-Bond adhesives. There was no statistically significant difference between the four dentin adhesive groups among all the evaluation periods regarding any evaluation criteria. However, four universal adhesives showed clinically acceptable marginal discoloration and marginal deterioration in a few restorations. CONCLUSION: Monomer contents of universal adhesives with self-etch mode had no significant effect on the success of restorations.

Immediate and Late Repair of Microhybrid Resin Composites: Effect of Silane Coupling Agent, Universal Adhesives and Photo Polymerization.

This study investigated the effect of silane coupling agent and universal adhesive application on repair bond strength of resin-based composite after bur grinding. Microhybrid resin composite (Charisma Smart) blocks (N=80; 8x8x4 mm3) were prepared, aged (37°C; 1 month), roughened, etched and randomly divided into two groups. Silane was applied to half of the groups (Porcelain Primer, Bisco), before one of the following universal primers/adhesives was applied: a) Scotchbond Universal (3M), b) All-Bond Universal (Bisco), c) G-Premio Bond (GC), and d) Clearfil SE Bond (Kuraray). In each adhesive group half of the group was photo-polymerized. The blocks were repaired with the same size resin composite and segmented into beams. Half of the beams were subjected to micro-tensile bond test (1 mm/min), while the other half was aged (37°C; 6 months) prior to testing. Failure modes were analyzed using Scanning Electron Microscopy (SEM). Data were analyzed using repeated measures of ANOVA, Tukey's post-hoc, and paired t-tests (alpha=0.05). The silane application did not affect the repair bond strength regardless of photo-polymerization of the adhesive resin. The repair bond strength decreased significantly after 6 months when adhesive resin was not photopolymerized (p⟨0.05). Photo-polymerizing universal adhesives might ensure higher repair bond strength and its maintenance after aging.

The clinical success of repaired posterior composite restorations with and without silane application.

OBJECTIVE: To evaluate the clinical success of posterior composite restorations repaired with and without silane application for up to 2 years. MATERIALS AND METHOD: In this retrospective study, patient record files acquired from the 40 patients who were treated due to needing repair for two class II defective composite restorations and visited the clinical practice for regular check-up visits were used. In the experimental group, the defective restorations were repaired using a silane coupling agent (Porcelain Primer), a universal adhesive (G-Premio Bond), and a microhybrid resin composite (Charisma Smart). In the control group, the restorations were repaired using the universal adhesive and the resin composite without silane coupling agent application. The repaired restorations were blindly assessed by two calibrated examiners using modified USPHS criteria at baseline, 6 months, 1, and 2 years. The data were analyzed using non-parametric tests (p = 0.05). RESULTS: After 2 years, 80 repaired class II restorations were evaluated. No restoration of either the control or silane-treated group failed. After 2 years, there were no statistically significant differences between the experimental and control groups (p > 0.05). The differences in surface roughness were observed in each group over time (p < 0.05). There were no variations in other criteria over time (p > 0.05). CONCLUSION: There was no significant effect of the silane coupling agent on restoration repair survival. CLINICAL RELEVANCE: The repair of localized defects of the posterior composite restorations either with or without silane application is a conservative treatment option that may increase the clinical success of these restorations.

Sixty-month follow up of three different universal adhesives used with a highly-filled flowable resin composite in the restoration of non-carious cervical lesion.

OBJECTIVE: The purpose of this clinical trial was to evaluate and compare the performances of three different universal adhesives used with a highly filled flowable universal resin composite in the restoration of non-carious cervical lesions (NCCLs) over a 60-month period. MATERIAL AND METHODS: Ninety-nine NCCLs were restored at 18 participants. NCCLs were divided into three different universal adhesive groups: Clearfil Universal Bond (CU) (n = 31), iBOND Universal (IU) (n = 33), and G-Premio Bond (GP) (n = 35). Prior to the adhesive procedures, selective enamel etching was performed with 37% phosphoric acid in all experimental groups. Adhesive systems were applied following the manufacturers' instructions, and the lesions were restored with a highly filled flowable resin composite (G-ænial Universal Flo). Restorations were finished and polished immediately after placement. All restorations were scored with regard to retention, marginal discoloration, marginal adaptation, sensitivity, surface texture, and color match using modified United States Public Health Service (USPHS) criteria after 1 week (baseline) and 6, 12, 18, 24, 36, and 60 months. Statistical analyses were performed using chi-square and McNemar's and Kaplan Meier tests. The level of significance was set at p < 0.05. RESULTS: After 60 months, the recall rate was 72.2%. Survival rates of CU, IU, and GP restorations were 87%, 85.2%, and 96.5%, respectively. Five CU (25%), 8 IU (34.8%), and 12 GP (42.9%) restorations exhibit bravo scores for marginal adaptation. However, no differences were seen among them. CU showed lower bravo score than IU and GP for marginal discoloration (CU, 0%; IU, 26.1%; GP, 32.1%). Two CU, 7 IU, and 6 GP restorations showed bravo scores for surface texture, and 2 (9.1%) CU and 1 (3.3%) GP restorations were scored as bravo score for color match (p > 0.05). CONCLUSION: The tested universal adhesives showed similar success rates during the 60-month follow-up. However, CU showed better clinical performance than IU and GP in terms of marginal adaptation and discoloration. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03415412 CLINICAL RELEVANCE: The long-term clinical performances of the three universal adhesives in the restoration of NCCLs using selective enamel etching mode were successful after 60 months.