Self-etch Adhesives Research Articles

Synthesis, characterization, photo-polymerization, hydrolytic stability, and etching behavior of new self-etch adhesive monomers

Considering the poor hydrolytic stability of the most methacrylate-based functional monomers of self-etch dental adhesives in acidic and aqueous conditions, in this study allyl-based photo-polymerizable self-etch monomers was synthesized in order to improve the hydrolytic stability.The new self-etch monomers based on phosphonic acid functional groups were synthesized through a two-step procedure. First, phosphoric anhydride, poly-phosphoric acid, and polyethylene glycol were reacted to produce phosphate ester precursor (P-PEG-P). Next, allyl 2, 3-epoxypropyl ether was reacted with P-PEG-P to synthesize allyl self-etch monomer. Glycidyl methacrylate was also reacted with P-PEG-P to synthesize a methacrylate self-etch analogue monomer. The monomers were characterized using FTIR and 1H-NMR spectroscopy. The viscosities of monomers were measured using a rheometer. The degree photopolymerization conversion of monomers was measured using FTIR spectroscopy. The pH assay was performed by a digital pH-meter. The etching behavior of the monomers on human teeth was studied using scanning electron microscopy (SEM). Thermo-gravimetric analysis (TGA) was performed to evaluate the possible interaction of the monomers with tricalcium phosphate (TCP). The solubility of synthesized monomers was examined in ethanol, acetone, and water. The hydrolytic stability of cured resins in artificial saliva during 4 months was also surveyed.The synthesis of new self-etching monomers was successfully confirmed by spectroscopy analyses. The results represented appropriate viscosity of self-etching monomers around 1 (Pa s). The resin containing methacrylate monomer exhibited its degree of conversion is more than that of allyl monomer (p < 0.05). The allyl and methacrylate self-etch monomers exhibited pH values of 1.2 and 1.3, respectively. SEM micrograph verified that the synthesized monomers were able to suitable etching of the enamel human premolar teeth. The data obtained from TGA tests revealed that thermal stability of (TCP) containing monomers is enhanced. Also, the monomers exhibited an excellent solubility in polar solvents, but when they are mixed with TCP, they are not, anymore, dissolved in these solvents. Furthermore, the allyl monomer showed higher hydrolytic stability than the methacrylate monomer.The new photo-polymerizable acidic monomer based on allyl functionality showed enhanced hydrolytic stability compared to methacrylate-based monomer. It may be considered as a promising monomer for self-etch dental adhesives.

Antibacterial one-step self-etching dental adhesive with silver nanoparticles synthesized in situ

ObjectivesThe objective of this study is to value the long-term antibacterial capability and adhesive properties of one-step self-etching dental adhesive containing silver nanoparticles (AgNPs) synthesized in situ. MethodsOne-step self-etching adhesives with various weight percentages of silver 2-ethylhezanoate (0%, 0.05%, 0.10%, and 0.20%) were obtained by in-situ synthesis; the sizes and distribution of the AgNPs in resin were observed. The antibacterial effects of dentin-resin specimens were assessed by various test methods after being aged for 1 week to 1 year. The microtensile bond strength (μTBS) and interfacial nanoleakage (NL) were evaluated using extracted human teeth after being aged for 1 day and 1 year. ResultsUniform distribution of AgNPs in resin was observed in all experimental groups, and the average size was 4.71 nm-4.81 nm. All groups containing AgNPs showed significant antibacterial differences from the control group (P<0.05) over the ageing of 1 year. Although the increase of concentration tended to improve antibacterial activity, significant differences were not observed between the 0.10% and 0.20% groups (P>0.05). No significant differences were observed between all experimental groups and the control group in μTBS testing and NL testing at 1-day and 1-year time points (P>0.05). Conclusions0.10% AgNPs synthesized in situ might be appropriate to impart a long-term antibacterial ability to the one-step self-etching adhesive, without affecting its adhesive performance. Clinical SignificanceThis study suggests that in-situ synthesis of AgNPs is an effective method to improve the antibacterial ability of dental adhesives with the potential to inhibit secondary caries.

A randomized clinical study of the performance of self-etching adhesives containing HEMA and 10-MDP on non-carious cervical lesions: A 2-year follow-up study

ObjectiveTo evaluate the association of HEMA and 10-MDP in the clinical performance of self-etching adhesives in the restoration of NCCLs during 2-years. Materials and methods60 restorations were performed in 17 volunteers and randomized into three groups: G1 (n = 20) - Prime and Bond Universal (10-MDP); G2 (n = 20) - Optibond All-in-One (HEMA); and G3 (n = 20) - Clearfil SE (10-MDP and HEMA). No cavity preparation was performed. After 2 years, the restorations were evaluated using the modified USPHS criteria for retention, marginal adaptation/ staining, postoperative sensitivity and secondary caries. The results were analyzed using Fisher's exact test and Kruskal–Wallis test. ResultsAll groups showed 100% retention rate, except G1, who lost two restorations (p > 0.05). Regarding marginal adaptation, G1 showed greater deficiency, as only eight restorations (40%) remained intact (p < 0.05). Regarding marginal staining, G1 and G2 showed higher rate, as only 12 restorations (65%) in each one were free of staining (p < 0.05). All groups showed similar results for postoperative sensitivity and secondary caries (p > 0.05). ConclusionThe association of HEMA and 10-MDP monomers in the self-etching adhesives did not influence the clinical performance of the NCCL restorations with respect to retention, postoperative sensitivity, and incidence of secondary caries. However, positively influenced the marginal adaptation and marginal staining at the 2-year follow-up. Clinical significanceThe association of HEMA and 10-MDP monomers in the self-etching adhesives positively influence the clinical performance of the NCCL restorations with respect to marginal adaptation and marginal staining.

Longevity and Clinical Performance of Direct Posterior Restorations

Various materials and techniques are employed, with composite resins being a popular choice. Factors influencing restoration longevity include material selection, practitioner skill, patient factors, and cavity characteristics. Recent developments in dental materials and techniques have expanded treatment options. Amalgam has historically exhibited superior longevity but faces declining usage due to aesthetic concerns. Composite resins have shown variable longevity, influenced by factors such as cavity location and size. Glass ionomer cements, while biocompatible, have limited mechanical strength. Tunnel restorations and atraumatic restorative treatment restorations have shown varying success rates. Advances in materials, techniques, and bonding agents are shaping the landscape of adhesive dentistry. Adhesive dentistry has evolved significantly with the decline of amalgam and the emergence of innovative materials. Challenges like polymerization shrinkage persist, but promising developments, such as low-shrinking monomers and nanoparticle fillers, are on the horizon. Self-etching adhesives have improved bonding. The longevity of posterior restorations depends on various factors, and practitioners must stay updated on these advancements for optimal patient care.Various materials and techniques are employed, with composite resins being a popular choice. Factors influencing restoration longevity include material selection, practitioner skill, patient factors, and cavity characteristics. Recent developments in dental materials and techniques have expanded treatment options. Amalgam has historically exhibited superior longevity but faces declining usage due to aesthetic concerns. Composite resins have shown variable longevity, influenced by factors such as cavity location and size. Glass ionomer cements, while biocompatible, have limited mechanical strength. Tunnel restorations and atraumatic restorative treatment restorations have shown varying success rates. Advances in materials, techniques, and bonding agents are shaping the landscape of adhesive dentistry. Adhesive dentistry has evolved significantly with the decline of amalgam and the emergence of innovative materials. Challenges like polymerization shrinkage persist, but promising developments, such as low-shrinking monomers and nanoparticle fillers, are on the horizon. Self-etching adhesives have improved bonding. The longevity of posterior restorations depends on various factors, and practitioners must stay updated on these advancements for optimal patient care.

Effect of nonthermal atmospheric plasma on bond strength of composite resin using total-etch and self-etch adhesive systems.

The aim of this study was to assess the impact of nonthermal atmospheric plasma (NTAP) on the bond strength of composite resin following plasma application at different steps of dentin bonding in total-etch and self-etch adhesive systems. Ninety extracted third molars were taken, and the occlusal surfaces were removed until the exposure of the dentin. Samples were distributed into two main groups: Group T: total-etch adhesive system and Group S: self-etch adhesive system. Groups are further subdivided (n = 10) based on plasma application at different steps of dentin bonding. T1: surface etching with 37% phosphoric acid and bonding agent application. T2: plasma application and bonding agent application. T3: plasma application, etching, and bonding agent application. T4: etching, plasma application, and bonding agent application. T5: etching, plasma application, bonding agent application, and again plasma application. S1: self-etch bonding agent application. S2: plasma application and bonding agent application. S3: Bonding agent application and plasma application. S4: plasma application, bonding agent application, and again plasma application. For all the samples, composite resin buildup was done, and shear bond strength (SBS) was measured. The contact angle was measured at different steps of dental adhesive systems. Two-way analysis of variance and the post hoc Tukey's test were used for analysis, regarding P < 0.05 as statistically significant. Among all groups of total-etch and self-etch adhesives, Group T4 (48.81 Mpa) and Group S2 (36.59 Mpa), respectively, have demonstrated significantly greater bond strength values than the corresponding control groups. NTAP enhanced the composite resin's SBS when plasma treatment was done before bonding agent application and significantly reduced the contact angles of the distilled water.

65 - Effect of papain enzyme on smear-layer deproteinization with functional monomers in self-etch adhesives

65 - Effect of papain enzyme on smear-layer deproteinization with functional monomers in self-etch adhesives

Experimental two-step universal adhesives bond durably in a challenging high C-factor cavity model.

To determine the bonding effectiveness of experimental 2-step universal adhesives (UAs) to high C-factor class-I cavity-bottom dentin and to assess the potential bond-strength contribution of an additional flowable composite layer. Three experimental 2-step UA formulations, involving the application of a 10-MDP-based primer followed by a hydrophobic adhesive resin with a 15-to-20-µm film thickness and differing only for filler, referred to as BZF-21 (silica and bioglass filler), BZF-29 (silica filler) and BZF-29_hv (higher silica-filler loading resulting in a higher viscosity), all prepared by GC, along with three representative commercial adhesives, Clearfil SE Bond 2 (C-SE2, Kuraray Noritake), G-Premio Bond (G-PrB, GC) and OptiBond FL (Opti-FL, Kerr), were comparatively investigated for their 'immediate' and 'aged' (50,000 thermocycles) micro-tensile bond strength (μTBS), when applied either in etch-and-rinse (E&R) or self-etch (SE) mode, to high C-factor class-I cavity-bottom dentin (n=10; 10 experimental groups). Four additional experimental groups involved the extra application of the flowable composite G-ænial Universal Flo (GC), employed as an intermediate liner in combination with the adhesives BZF-29 and G-PrB and again applied both in E&R or SE mode. Statistical analysis was performed using linear mixed-effects (LME) modelling and linear regression analysis (p<0.05). All 2-step UAs performed similarly when compared to the gold-standard E&R Opti-FL and SE C-SE2 adhesives, except for the aged μTBS of BZF-29_hv applied in E&R mode, and significantly outperformed the 1-step UA G-PrB. Significant reduction in μTBS upon aging was only recorded for 2-step UAs applied in E&R mode. The extra flowable composite layer significantly improved G-PrB's μTBS. The experimental 2-step UAs revealed favorable bonding performance in the challenging high C-factor class-I cavity model, comparable to that of the multi-step gold-standard E&R and SE adhesives and superior to that of the 1-step UA investigated. An additionally applied flowable composite layer compensated for the lower bonding effectiveness of the 1-step UA in the high C-factor cavity model.

Microshear Bond Strength of Self-Etch Adhesive Incorporated with Seashell, Pearl, and Hydroxyapatite Nanoparticles to Dentin

Microshear Bond Strength of Self-Etch Adhesive Incorporated with Seashell, Pearl, and Hydroxyapatite Nanoparticles to Dentin

Influência do adesivo autocondicionante na resistência de união em dentes submetidos à radiação

ABSTRACT This study aimed to conduct a literature review about the influence of self-etching adhesives on the bond strength of restorative procedures for irradiated teeth. The search for articles was carried out on six databases (PubMed, Scopus, Web of Science, Embase, LILACS, Cochrane). Gray literature (Google Scholar) and reference lists of included studies were evaluated. The keywords used were: “Radiotherapy” OR “Radiation Therapy” OR “Radiation Treatment” OR “Radiation Effects” OR “Radioterapia” OR “Terapia por radiação” OR “Tratamento por radiação” OR “Efeitos da Radiação” OR “Terapia por Radiación” OR “Tratamiento por Radiación” OR “Efectos de Radiación” AND “Dentin-Bonding agent” OR “Adesivos Dentinários” OR “Recubrimientos Dentinarios”. The inclusion criteria were laboratory and clinical studies, dissertations, literary and systematic reviews, and no time and language restrictions. Three hundred and eighteen studies were identified in the databases, 30 in the gray literature, and 5 from the reference list of included articles. 40 were excluded for being duplicates. After reading the title and abstract, 28 articles remained for complete analysis. In the end, 21 articles were included in this study. Self-etching could be a good option for irradiated teeth restorations. However, further clinical studies are needed.

Iontophoresis effects of two-step self-etch and total-etch systems on dentin permeability and sealing of composite restoration under simulated pulpal pressure.

Studies demonstrated the bond strength enhancement and the decrease in degradation of the adhesive interface after applying either self-etch adhesives or two-step, etch-and-rinse adhesives under an electric field. However, the presence of dentinal fluid driven by the pulpal pressure in vivo is a profounding factor affecting both the sealing ability and bond strength of adhesives. This study aimed to evaluate the effect of three-step etch-and-rinse and two-step self-etch adhesives when applied with iontophoresis under simulated pulpal pressure on the permeability of dentin, resin infiltration, and the sealing ability of resin composite. The experiments were done on 32 recently extracted premolars, randomly assigned into four groups (n = 8) according to two adhesive systems (SBMP and SE), applied following the manufacturer's instructions (control) for two groups or with iontophoresis for the others (SBMPi and SEi). For the iontophoresis, the anodal current was applied at 75μA for 20s through the cavity electrode during the bond. The fluid flow rate of dentin was recorded after cavity preparation (smear-layer-covered dentin; T1), bonding (T2), and composite restoration (T3) during the maintained pulpal pressure of 20mmHg. The flow rates were expressed as a percentage relative to the initial smear-layer-covered value for each specimen. Results were analyzed using repeated measures ANOVA. Scanning electron microscopy (SEM) was performed to observe the resin/dentin interface. There were no significant increases in the mean flow rates from T1 to T3 in the SBMP (P = 0.355), while these changes in the SE were significant between T1 (100%) and T2 (166.77%) and T1 and T3 (221.16%) (P = 0.002; one-way RM ANOVA; Holm-Sidak test). For the iontophoresis groups, the mean flow rates decreased significantly from T1 to T2 and T1 to T3 of both SBMPi (T2 = 86.43, and T3 = 79.53; P < 0.001) and SEi groups (T2 = 87.96, and T3 = 81.48; P = 0.004). The iontophoresis of both adhesives produced the optimal resin infiltration with improved quality of the hybrid layer and resin tags. SBMP bonded with or without iontophoresis performed better sealing ability than SE under the same condition. Both adhesives applied with anodal iontophoresis significantly decreased the dentin permeability, contributing to the improved resin infiltration.

Shear Bond Strength of Two Self-Etching Adhesives to Air-Abraded Dentin: An in Vitro Study

Background: The aim of this research was to study the effect of air-abrasive treatment of dentin on the chemical composition of its surface and the adhesion strength of 2 self-etching adhesive systems (AS). Methods and Results: Powders based on aluminum oxide (Al2O3) (27µm) (KaVo, Biberach, Germany), sodium bicarbonate (NaHCO3) (40µm) (AIR-FlOW Classic Comfort, EMS, Nyon, Switzerland), and erythritol (14µm) (AIR-FLOW Plus, EMS, Nyon, Switzerland) were used for the air-abrasive treatment of adhesive surfaces. Bonding steps were carried out with Single Bond Universal (SBU) (3M ESPE, USA) and Bond Force 2 (BF2) (Toquyama, Japan). The adhesion strength of composite to dentin was evaluated on 80 samples prepared in accordance with the Ultradent Shear Bond Strength test. All samples were divided into 4 groups depending on the method of dentin surface processing. In the samples of Group 1 (n=20), aluminum oxide was used for the air-abrasive treatment of dentin. In Group 2 (n=20) and Group 3 (n=20), samples were treated using powders based on sodium bicarbonate and erythritol, respectively. Group 4 (control, n=20) included tooth samples in which the dentin surface was not air-abraded after preparation with carbide burs. Then, each group was divided into 2 subgroups (Sub-A and Sub-B) depending on the type of adhesive system used. Adhesive resin was applied and polymerized in accordance with the manufacturer’s instructions. Single Bond Universal (SBU) was used for the samples of Sub-A, and Bond Force 2 (BF2) (Toquyama, Japan) was used for the samples of Sub-B. Scanning electron microscopy and determining the surface elemental composition of samples were carried out on an SEM-EVO MA 10 (Carl Zeiss) and energy dispersive X-ray spectrometer with EDS Aztec Energy Advanced X-Act (Oxford Instruments). It was concluded that air-abrasive treatment of the dentin surface does not enhance the adhesion strength of composite material when using self-etch AS. Also, it was noted that the pH level of self-etch AS is not a crucial feature in determining the strength of the filling-tooth interface. The resulting variations in the elemental composition of dentin surface after air-abrasion with various mixtures and their effect on the efficacy of the different AS require further in vitro studies.

Hydroxyapatite Affects the Physicochemical Properties of Contemporary One-Step Self-Etch Adhesives.

The study aimed to evaluate the influence of the manipulation surfaces on the physical properties of one-step self-etch adhesives (1-SEAs). Scotchbond Universal (SBU), Clearfil Universal Bond Quick ER (UBQ), and an experimental adhesive (UBQexp) were manipulated on different surfaces: manufacturer's Teflon-based dispensing dish (TD) or hydroxyapatite plate (HA). After manipulation of the adhesives, the pH of each 1-SEA was measured. Samples of each adhesive/manipulation surface were prepared and subjected to water sorption (WS)/solubility (SL) and flexural strength tests. The modulus of elasticity (E) was measured in dry and wet conditions before and after 24 h water storage, and the percentage of variation of E (ΔE) was calculated. Results were analyzed using the t-test with Bonferroni corrections (α = 0.05). When adhesives were manipulated on the HA plate, there was a significant increase in the adhesives' pH. WS and SL of all 1-SEAs decreased when the HA was used. Only SBU showed higher flexural strength when manipulated on the HA compared to the manipulation on TD under dry and wet conditions. For each 1-SEA, the use of HA resulted in significantly higher E in dry and wet conditions. ΔE of all adhesives was smaller with the manipulation on HA than on TD. It was concluded that the manipulation of 1-SEA on a hydroxyapatite plate considerably affected the adhesives' properties.

Influence of silver nanoparticles on the resin-dentin bond strength and antibacterial activity of a self-etch adhesive system

Statement of problemThe influence of silver nanoparticles on adhesive properties of Single Bond Universal (3M ESPE) and the antibacterial activity of silver nanoparticles-modified adhesives against Streptococcus mutans is unclear. PurposeThe purpose of this in vitro study was to evaluate the effect of silver nanoparticles on the dentin bond strength of modified adhesives and the antibacterial activity against the cariogenic pathogen S. mutans. Material and methodsSingle Bond Universal adhesive was used as the control. Silver nanoparticles were added to adhesives at 0.05% and 0.1% (by weight) (experimental groups), and scanning electron microscopy was used to observe the uniformity of the modified adhesives. The Single Bond Universal adhesive and the modified adhesives were then used to prepare dentin-composite resin blocks. The microtensile bond strength and microleakage of the prepared dentin-composite resin blocks were determined with or without thermocycling. The colony-forming units (CFU) of S. mutans cultured with the adhesives were evaluated, and the microtensile bond strength and microleakage of each group were tested after treatment with S. mutans. The differences in the microtensile bond strength or CFU were analyzed by using the 2-way analysis of variance and independent sample t test. The differences in microleakage between the groups were evaluated by using the Mann-Whitney test (α=.05). ResultsSilver nanoparticle-modified adhesives exhibited uniform morphologies without agglomeration and exhibited a homogeneous adhesive layer in dentin-composite resin blocks. The microtensile bond strength and microleakage of the modified adhesives were similar to those of the control group, with or without thermocycling (P>.05). However, thermocycling reduced the bond strength significantly (P<.001). Self-etch adhesives incorporated with silver nanoparticles showed significant antibacterial activities after less than 6 months of aging treatment. The modified adhesives did not exhibit a decreased bond strength after S. mutans exposure (P>.05), while the control group exhibited a markedly decreased bond strength after S. mutans exposure (P<.05). ConclusionsSilver nanoparticle-modified adhesives showed excellent antibacterial activities against S. mutans and resisted the destruction of dentin bond strength caused by S. mutans while not compromising the bonding properties of Single Bond Universal self-etch adhesives.

Primer application technique and remaining dentin thickness affected microtensile bond strength of contemporary dentin adhesives under simulated pulp pressure.

To evaluate the effect of application techniques, type of adhesives and remaining dentin thicknesses on microtensile bond strength (µTBS) of 3 adhesive systems. 112 flat occlusal dentinal surfaces of third molar were randomly allocated into 16 groups based on 2 remaining dentin thicknesses (RDT), 2 application techniques, and 3 adhesive systems (Optibond FL, OFL; Clearfil SE Bond, CSE; and Single Bond Universal, SB); SB was applied in either etch-and-rinse (ER) or self-etch (SE) mode. Simulated pulpal pressure was performed during restorative procedure and water storage. The stick-shaped specimens from each tooth underwent µTBS testing. The data were evaluated using a paired t test and ANOVA followed by a post hoc test. The fractured specimens were evaluated for mode of failure using a stereomicroscope. The mean µTBS values were significantly affected by RDT, application technique, and types of adhesives. Neither RDT nor application technique affected µTBS of SB in ER mode, whereas application technique affected both conventional and universal self-etch adhesives. RDT also influenced µTBS of OFL. RDT and application technique differently affected the µTBS of dentin bonding which was product-related. Etch-and-rinse systems had higher bond strength to superficial than to deep dentin, whereas self-etch systems were more sensitive to both RDT and application technique. The universal adhesive is less sensitive to intrinsic wetness and can be used according to manufacturer's instructions.

Comparison of Retention and Marginal Discoloration of Self-Etch and Total-Etch Adhesives before Pit and Fissure Sealant Application on Permanent Second Molars in Pediatric Patients. A 1-year follow-up longitudinal study

Objective: To compare the retention and marginal discoloration of Self-etch and Total Etch Adhesive during Pit and Fissure Sealant application at 1 month, 3 months, 6 months, and 12 months. Materials and methods: 30 school-going children received sealants in all four permanent second molars, carried out in the Department of Pedodontics and Preventive Dentistry. The fully erupted second permanent molars were randomly allocated into 3 groups: group A (self-etch), B (Total etch), and C (control group). According to the split mouth design, each patient received sealant in the second molar with self-etch in one arch and total-etch in the other arch; contra-lateral molars were kept in the control group. Results: No statistically significant difference was found in the marginal discoloration and microleakage of fissure sealants placed on occlusal surfaces following use of an SE bonding agent and traditional TE adhesive after 12 months. Conclusion: When TE adhesive was put on before sealant, the same amount of microleakage or marginal discoloration happened in the occlusal fissure of permanent teeth as when SE adhesive was put on before sealant.

Incorporation of calcium hydroxide to experimental self-etch adhesives for improved long-term dentin bonding

This study investigated the degree of conversion (DC), calcium release (CaR), and long-term dentin bond stability (DBS) of experimental self-etch adhesive systems containing calcium hydroxide. Four adhesive systems were formulated including UDMA, HEMA, GDMA-P monomers, TPO and diphenyl iodonium as photoinitiator system, and ethanol/water as solvent with different mass fractions of calcium hydroxide: 0% (control), 1%, 2% and 4%. The DC was evaluated through Fourier Transform Infrared spectroscopy coupled to an attenuated total reflectance device. The CaR was evaluated through a spectrophotometer after 3 h up to 168 h. The DBS was measured through the microtensile bond strength method through a microtensile testing machine after 24 h and 12 months of water storage. The data were statistically evaluated using one- and two-way ANOVA and Tukey's post-test (p < 0.05). The DC of all adhesive systems was statistically similar (p > 0.05). No material released calcium up to 168 h after photoactivation. For DBS, adhesive systems containing 0%, 1% and 4% calcium hydroxide showed statistically similar means between immediate (24 h) and 12-month time-points. The adhesive system containing 2% calcium hydroxide showed statistically higher bond strength at 12-month time-point (p = 0.001). The inclusion of calcium hydroxide to experimental adhesive systems tested did not affect the DC and calcium release. However, the inclusion of 2% calcium hydroxide was able to improve long-term dentin bond strength.

Comparison of Different Adhesive Systems on Bond Strength of Resin Composite Posts Placed in Primary Teeth.

Background This study evaluated the push-out bond strength of resin composite posts to the intracanal dentin in primary teeth using different adhesive systems. Materials and Methods In this experimental study, sixty-eight primary lateral incisors were randomly allocated in four groups (n = 17): Adper Single Bond 2 (ASB), Clearfil SE Bond 2 (CSE), G-Premio Bond in etch-and-rinse mode (GP-ER), and G-Premio Bond in the self-etch mode (GP-SE). The coronal one third of root canals was filled with resin composite. The push-out test was performed using a universal testing machine. ANOVA and LSD tests were used to analyze the data (P < 0.05). Results One-way ANOVA showed significant differences between the four groups in push-out bond strength (P = 0.002). The ASB and GP-SE groups showed lower and higher bond strengths, respectively. The failure mode distribution did not differ between the bonding agents used (P = 0.763). Adhesive and mixed failures were more frequent. Conclusion The GP-SE, GP-ER, and CSE exhibited significantly higher push-out bond strength than ASB. A universal adhesive system and 6th generation self-etch adhesives are recommended for use with resin composite posts in primary anterior teeth. Regarding the advantages of these bonding agents, such as fewer clinical steps, lower technical sensitivity, and easy application, they can be a good option for restoring primary teeth with short resin composite posts.

Effect of nanosecond- and microsecond-pulse Er,Cr:YSGG laser ablation on dentin shear bond strength of universal adhesives.

The study aimed to evaluate the bond strength of universal adhesives to dentin after Er,Cr:YSGG laser irradiation with nanosecond-domain and microsecond-domain pulses. Eighty extracted caries-free, sound human molars were divided into eight groups. The enamel was removed until the dentin occlusal flat dentin surface was exposed. Etch-and-rinse followed by adhesive was applied to group 1, and a self-etch adhesive was applied to group 2. Er,Cr:YSGG laser (3mJ, 100Hz, 100ns), (3mJ, 100Hz, 150μs), and (20mJ, 100Hz, 150μs) were applied to groups 3-4, 5-6, and 7-8, respectively. The laser preparation was followed by self-etch adhesives or adhesives treatment. When the composite resin had been built up on the samples, the shear bond strength was tested, and the data were statistically analyzed using analysis of variance (ANOVA). Groups prepared with nanosecond-pulse laser showed significantly higher bond strength values than the microsecond-pulse laser groups and self-etch mode group, and the SEM photographs also showed more dentinal tubules and no damage in the ablation area. The shear bond strength of long pulse laser ablated was comparable to that of self-etching system when it was combined with a self-etch adhesive at low energy, but higher energy laser degraded shear bond strength. The pulse width of Er,Cr:YSGG laser affects the bond strength, nanosecond pulses of laser irradiation without water cooling can enhance bond strength, but microsecond pulses of laser cannot enhance bond strength.

Self-conditioning adhesives in pediatric dentistry: an integrative literature review

As clinical time must be taken into account in pediatric dental care, the use of self-etching accessories is the best alternative for restorative procedures in this population. Cons suitable accessories, which require a conditioning time, self-etching accessories and time separators with the number of steps and the number of steps required. However, this theme is still not clear in the literature. Thus, the objective of this integrative literature review was to compare, in relation to their clinical performance and their adhesive properties, self-etching accessories compared to the performance of restorations compared to primary teeth. The search was performed on Pubmed, Google Scholar and EBSCOHost with the descriptors “dentin-bondin agents OR dentin-bonding system” AND “deciduous OR primary teeth” AND “self-etch adhesive OR self-etch system” Per studies from the last five years . Thirty-six articles were obtained and five were selected. In only one study, self-etching adhesives and performance differences between their self-etching characteristics and performance differences between the evaluated characteristics. Therefore, studies selected for the selected studies, randomly selected and with study time are considered better that are not more rigid and that are more rigid in randomized trials and that have been considered as time period.

Delayed light activation of resin composite affects the bond strength of adhesives under dynamic simulated pulpal pressure.

To evaluate the effect of a time delay before the light activation of resin composite on the microtensile bond strength (µTBS) of self-etch adhesives under dynamic simulated pulpal pressure. One hundred twenty crown segments were prepared from human third molars. Dentin surfaces were prepared with coarse diamond burs and connected to a dynamic pulpal pressure device. The self-etch adhesives used were Clearfil SE Bond (CSE), G2-Bond Universal (G2B), Clearfil Universal Bond Quick (CBQ), and G-Premio Bond (GPB). Each adhesive was divided into 3 subgroups: immediate light activation of resin composite (T0), delayed light activation for 150s (T1), and 300s (T2). The µTBS data were obtained after 24-h water storage. Scanning electron microscopy was used to evaluate the nanoleakage at the resin-dentin surface. The µTBS data were analyzed using two-way ANOVA and Duncan's multiple comparisons. All adhesives demonstrated a significant reduction in µTBS at T2, except for CBQ where the bond strength was not affected by the delayed light activation times. The two-step self-etch adhesives (CSE and G2B) demonstrated higher bond strength than the one-step adhesives at all conditions. Nanoleakage was observed in all adhesives at T2; however, nanoleakage was detected only in CBQ and GPB at T1. Delayed light activation of resin composite adversely affected the dentin bond strength of self-etch adhesives. Two-step self-etch adhesives had better bonding performance than one-step self-etch adhesives. After adhesive application, resin composite should be adapted and cured as soon as possible.