The Effect of Laser Irradiation to Surfaces of Computer-Aided Design/Computer-Aided Fabrication Resin Blocks Coated with a Silane Coupling Agent on Bond Strength between the Resin Blocks and Composite Resin.

The aim of this study was to investigate the effect of laser irradiation to computer-aided design/computer-aided fabrication (CAD/CAM) resin blocks coated with a silane coupling agent on the bond strength between resin blocks and composite resin. The CAD/CAM resin blocks used in this study were Cerasmart 300 (GC) and Vita Enamic (Vita); they were cut into plates and then subjected to a series of treatments. After processing with a silane coupling agent, treatment with a semiconductor laser was performed at 3.0, 5.0, and 7.0 W, followed by bonding procedures. The control group included those exposed to silane and bonded without laser application. After bonding, a mold with a simulated cavity was formed on the specimen and filled with flowable composite resin, and they were stored for 24 h or stressed by thermal cycling for subsequent testing that assessed the shear bond strength (n = 10). The results revealed that the bond strength was significantly enhanced by laser irradiation after applying a silane coupling agent (p < 0.03), whereas significant increase was not detected between the materials (p > 0.05). Particularly, 7 W laser irradiation had a significant increase on the bond strength between the composite resin and Cerasmart block after thermal cycling (p = 0.009). The SBS of the composite resin to CAD/CAM resin blocks was significantly enhanced by laser irradiation after silane coupling agent application.

Toothbrush Abrasion of Restorations Fabricated with Flowable Resin Composites with Different Viscosities In Vitro.

The purpose of this study was to examine toothbrush-induced abrasion of resin composite restorations fabricated with flowable resin composites of different viscosities in vitro. In this study, six types of flowable resin composites with different flowability (Beautifil Flow F02, F02; Beautifil Flow F10, F10; Beautifil Flow Plus F00, P00; Beautifil Flow Plus F03, P03; Beautifil Flow Plus X F00, X00; and Beautifil Flow Plus X F03, X03) were used. For the toothbrush abrasion test, the standard cavity (4 mm in diameter and 2 mm in depth) formed on the ceramic block was filled with each flowable resin composite (n = 10) and brushed for up to 40,000 strokes in a suspension containing commercial toothpaste under the conditions of 500 g load, 60 strokes/min, and 30 mm stroke distance. After every 10,000 strokes, the brushed surface of the specimen was impressed with a silicone rubber material. The amount of toothbrush-induced abrasion observed on each impression of the specimen was measured using a wide-area 3D measurement device (n = 10). The viscosity was determined using a cone-and-plate rotational measurement system. Because of the effect of different shear rates on viscosity and clinical use, the values 1.0 and 2.0 s-1 were adopted as data (n = 6). In this study, the results of the toothbrush abrasion test demonstrated no significant differences in the amount of toothbrush-induced abrasion among flowable resin composites used (p > 0.05). No significant correlation was reported between toothbrush-induced abrasion and viscosities of flowable resin composites.

Dentin bond strengths of all-in-one adhesives combined with different manufacturers' flowable resin composites.

The present study aimed to evaluate the dentin bond strengths of all-in-one adhesives in combination with flowable-resin-composites of different manufacturers. The materials used in this study were two all-in-one adhesives (BeautiBond Multi, BM, and Clearfil Bond SE ONE, SE) and four flowable resin composites (Clearfil Majesty ES Flow, CME; Estelite Flow Quick, EFQ; MI Flow II, MIF; and Beautifil Flow Plus F03, BFP). By combining each all-in-one adhesive and flowable resin composite, eight experimental groups were established. The shear bond strengths (SBSs) in each group were measured, and the data were statistically analyzed using one-way analysis of variance. The SBSs of the group that used SE showed no significant differences among all flowable resin composites (p>0.05), whereas those of the group that used BM showed significant differences between BFP and CME, and CME and EFQ. The combinations showed dentin bond strength ranging approximately from 20 to 30 MPa.

Pulp tissue reaction to a self-adhesive, resin-based direct pulp capping material containing surface pre-reacted glass-ionomer filler.

OBJECTIVE: This study aimed to evaluate the effect of direct pulp capping using an experimental self-adhesive resin for direct pulp capping (SRD) containing silica and surface pre-reacted glass-ionomer (S-PRG) filler on pulpal healing and to monitor the dentin bridge formation in rat pulp 2-4 weeks after operation. METHODS: Five types of SRDs (SRD-0: S-PRG fillers 0 wt%; SRD-1: S-PRG fillers 9.1 wt%; SRD-2: S-PRG fillers 18.4 wt%; SRD-3: S-PRG fillers 27.8 wt%; and SRD-6: S-PRG fillers 57.4 wt%) were prepared, and mineral trioxide aggregate (MTA) was used as control (n = 8). Direct pulp capping was performed on rats that were sacrificed for further evaluation 2 or 4 weeks after the operation. The pulp tissue disorganization (PTD), inflammatory cell infiltration (ICI), and reparative dentin formation were histopathologically evaluated; the data were statistically analyzed using the Kruskal-Wallis and the Mann-Whitney U tests. RESULTS: The histopathological evaluation of SRD-1-treated test animals 2 weeks post-operation revealed inferior PTD and ICI when compared with that of MTA. Even 4 weeks after the operation in SRD-1- and SRD-2-treated rats, the PTD and ICI were inferior when compared with those of MTA. The dental specimens of SRD-0 and MTA showed orthodentin formation, whereas SRD-treated test animals showed osteodentin formation at a position slightly deeper than the site of the pulpal exposure. SIGNIFICANCE: The reparative dentin formed by SRD-0 and MTA was genuine, whereas that formed by SRD-3 and SRD-6 was ossified and ectopic. SRD may have the potential to be utilized clinically as a direct pulp capping material.

Amorphous nanoparticles in clays, soils and marine sediments analyzed with a small angle X-ray scattering (SAXS) method.

This paper describes the amounts and size distributions of amorphous nanoparticles in clays, soils and marine sediments, and the effect of amorphous nanoparticles on the properties of clays, soils and marine sediments. So far aluminum-silicate amorphous nanoparticles such as allophane were observed only in soils of volcanic origin with a transmission electron microscope, and thus most people believed that aluminum-silicate amorphous nanoparticles were present only in soils of special origin. Recently, a method has been devised to quantify amorphous nanoparticles by using small angle X-ray scattering intensity. Using the method, we have quantified amorphous nanoparticles in clays, soils and marine sediments, and have found that all clays, soils and marine sediments measured in this study contain large amounts of amorphous nanoparticles. On the basis of this result, we have concluded that large amounts of amorphous nanoparticles are ubiquitously formed from rocks when the rocks are weathered or altered. We have also found that the amorphous nanoparticles affect the properties of clays, such as adsorption properties and plasticity. These findings show that amorphous nanoparticles play an important role in clays, soils and marine sediments.

Effect of various surface treatments on the bond strength of resin luting agent and the surface roughness and surface energy of CAD/CAM materials.

The aim of this study was to examine the effect of various surface treatments on the bond strength of a resin luting agent and the surface roughness and surface energy of computer-aided design and computer-aided manufacturing (CAD/CAM) materials. Four types of CAD/CAM blocks (Shofu Block HC: BHC; GC Cerasmart: CER; VITA Enamic: ENA; and Lava Ultimate: LAV) were used. All blocks were randomly divided into eight groups based on the surface treatment as follows: no surface treatment (C), airborne-particle abrasion (AA), hydrofluoric acid etching (HA), silane coupling agent application (SL), AA/SL, HA/SL, AA/HA, and AA/HA/SL. The microtensile bond strength (µTBS), surface roughness and surface energy were measured. Three-way ANOVA revealed that all surface treatments significantly influenced the µTBS between the resin luting agent and all types of CAD/CAM materials; however, the effect of each surface treatment on surface roughness and energy was dependent on the CAD/CAM materials.

Quantifying nanoparticles in clays and soils with a small-angle X-ray scattering method.

Clays and soils produce strong small-angle X-ray scattering (SAXS) because they contain large numbers of nanoparticles, namely allophane and ferrihydrite. These nanoparticles are amorphous and have approximately spherical shape with a size of around 3-10 nm. The weight ratios of these nanoparticles will affect the properties of the clays and soils. However, the nanoparticles in clays and soils are not generally quantified and are sometimes ignored because there is no standard method to quantify them. This paper describes a method to quantify nanoparticles in clays and soils with SAXS. This is achieved by deriving normalized SAXS intensities from unit weight of the sample, which are not affected by absorption. By integrating the normalized SAXS intensities over the reciprocal space, one obtains a value that is proportional to the weight ratio of the nanoparticles, proportional to the square of the difference of density between the nanoparticles and the liquid surrounding the nanoparticles, and inversely proportional to the density of the nanoparticles. If the density of the nanoparticles is known, the weight ratio of the nanoparticles can be calculated from the SAXS intensities. The density of nanoparticles was estimated from the chemical composition of the sample. Nanoparticles in colloidal silica, silica gels, mixtures of silica gel and α-aluminium oxide, and synthetic clays have been quantified with the integral SAXS method. The results show that the errors of the weight ratios of nanoparticles are around 25% of the weight ratio. It is also shown that some natural clays contain large fractions of nanoparticles; montmorillonite clay from the Mikawa deposit, pyrophillite clay from the Shokozan deposit and kaolinite clay from the Kanpaku deposit contain 25 (7), 10 (2) and 19 (5) wt% nanoparticles, respectively, where errors are shown in parentheses.

Effects of the percentage of air/water in spray on the efficiency of tooth ablation with erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation.

We aimed at examining the effects of a percentage of air/water in spray on the cutting efficiency of Er,Cr:YSGG laser for enamel and dentin. The intensity and frequency of irradiation were 3.0 W and 20 Hz for the enamel surface and 2.0 W and 20 Hz for the dentin surface, respectively. Flattened surfaces of enamel and dentin were irradiated at nine points for approximately 1 s under various percentages of air/water in spray using Er,Cr:YSGG laser. A high-speed video microscope was used to record each laser irradiation on the tooth surface. A slow video image was used to count the number of water micro-explosions yielded on the tooth surface during laser irradiation. A surface roughness tester was used to measure the depth of the dimple prepared with laser irradiation on each specimen. Each individual depth of dimple was divided by the number of water micro-explosions (pulse). This allowed for the calculation of the cutting depth per pulse. Following laser irradiation, several representative specimens were observed using an SEM. Two-way ANOVA was used as the statistical analysis. This revealed that there was no significant effect of the percentage of air/water in spray on the cutting depth for enamel surface (p > 0.05). On the contrary, a significant effect was observed in air-ratio for dentin cutting (p < 0.05). Both enamel and dentin were characterized by the presence of rough surfaces, as shown by the SEM images of the dimples. The percentage of air/water in spray was not significantly effective in laser cutting for enamel. Air-percentage was significantly effective in laser cutting for dentin.

Histopathological findings of an exposed human pulp carbonised by CO2 laser irradiation: A case report.

This report shows the healing process of an exposed pulp carbonised by CO2 laser irradiation prior to the application of a capping material. Six intact teeth from four volunteers were irradiated by CO2 laser and randomly capped with either an adhesive resin (SE bond) (n = 3) or calcium hydroxide-based cement (Dycal) (n = 3). The laser was operated in super-pulsed mode (power output, 0.5 W) for an irradiation time of 30 s. All cavities were restored with composite resin. Each tooth was extracted at approximately 30, 50 or 260 days post treatment and prepared for histological evaluation. CO2 laser irradiation controlled exudate and bleeding from each exposed pulp. Histological images revealed Dycal promoted complete dentine bridge formation at the carbonised pulp surface, and laser energy affected not only the pulp surface but also the deeper part of the pulp chamber.

Effects of color lenses on visual evoked magnetic fields following bright light.

Photophobia is a common condition in which bright light causes an unpleasant feeling due to increased sensitivity to light. In addition to discomfort, photophobia may be accompanied by visual dysfunction. The present study was conducted in order to examine whether visual evoked cortical responses contribute to the assessment of visual dysfunction due to bright light. Visual evoked magnetic fields (VEFs) following the presentation of a uniform bright light of 200-3700 cd/m2 in the lower visual field were recorded in 10 healthy volunteers and the effects of five color lenses: yellow, blue, gray, green, and colorless, were examined. VEFs were subjected to a multi-dipole analysis that resulted in the separation of several source activities, including the retina, V1, V2, V6, and fusiform gyrus. Source activity in the retina corresponding to the ERG b-wave exhibited a reduced amplitude and elongated peak latency with the yellow lens. Its latency strongly correlated with transmittance at 450 nm. On the other hand, cortical activities in V1 and the fusiform gyrus were stronger with the yellow lens than with the other color and colorless lenses. Only blue-light blocking showed significant effects. The result showing that the yellow lens enhanced V1 and fusiform activities indicated that processing in these areas was improved when subjects used this lens. The combination of delayed retinal activity and increased visual cortex activity may be an objective indicator of the effects of a color lens on visual function.

Effect of filler size and filler loading on wear of experimental flowable resin composites.

The relationship between wear resistance and filler size or filler loading was clarified for the universal resin composite; however, their relationship in flowable resin composites has not been clarified. The purpose of this study was to investigate the effect of filler size and filler loading on wear of experimental flowable resin composites by using a cyclic loading device. Nine experimental flowable resin composites consisting of three different sizes (70, 200 and 400 nm) and loading (50, 55 and 60 wt%) of filler were prepared. Bowl-shaped cavities were prepared on a flat surface of ceramic blocks using a No. 149 regular cut diamond point. The cavities were treated with a silane coupling agent and an all-in-one adhesive and then filled with each experimental flowable resin composite. The restored surfaces were finished and polished with a 1500-grit silicon carbide paper. The specimens were subjected to an in vitro two-body wear test using a cyclic loading device. The localized worn surfaces were evaluated at 10,000, 20,000, 30,000, and 40,000 cycles using a computer-controlled three-dimensional measuring microscope (n=5). The volumetric wear loss of the materials was calculated automatically by the equipment. Data were statistically analyzed with two-way ANOVA and post hoc Tukey test. Two-way ANOVA showed that the filler size significantly influenced wear volume (p<0.003), but the filler loading did not have a significant effect (p>0.05). A post hoc Tukey test detected significant differences in filler size between 70 nm and 400 nm, and 200 nm and 400 nm (p<0.007). The experimental flowable resin composite containing a mean filler size of 400 nm exhibited significantly lower wear resistance in two-body wear compared with those containing mean filler sizes of 200 nm or 70 nm.

Effect of filler size and filler loading on wear of experimental flowable resin composites

Abstract The relationship between wear resistance and filler size or filler loading was clarified for the universal resin composite; however, their relationship in flowable resin composites has not been clarified. Objectives: The purpose of this study was to investigate the effect of filler size and filler loading on wear of experimental flowable resin composites by using a cyclic loading device. Material and Methods: Nine experimental flowable resin composites consisting of three different sizes (70, 200 and 400 nm) and loading (50, 55 and 60 wt%) of filler were prepared. Bowl-shaped cavities were prepared on a flat surface of ceramic blocks using a No. 149 regular cut diamond point. The cavities were treated with a silane coupling agent and an all-in-one adhesive and then filled with each experimental flowable resin composite. The restored surfaces were finished and polished with a 1500-grit silicon carbide paper. The specimens were subjected to an in vitro two-body wear test using a cyclic loading device. The localized worn surfaces were evaluated at 10,000, 20,000, 30,000, and 40,000 cycles using a computer-controlled three-dimensional measuring microscope (n=5). The volumetric wear loss of the materials was calculated automatically by the equipment. Data were statistically analyzed with two-way ANOVA and post hoc Tukey test. Results: Two-way ANOVA showed that the filler size significantly influenced wear volume (p<0.003), but the filler loading did not have a significant effect (p>0.05). A post hoc Tukey test detected significant differences in filler size between 70 nm and 400 nm, and 200 nm and 400 nm (p<0.007). Conclusion: The experimental flowable resin composite containing a mean filler size of 400 nm exhibited significantly lower wear resistance in two-body wear compared with those containing mean filler sizes of 200 nm or 70 nm.

Histological evaluation of direct pulp capping with all-in-one adhesives in rat teeth.

The aim of this study was to histologically evaluate direct pulp capping using different all-in-one adhesives in rat teeth. Five all-in-one adhesives and a control material (MTA) were used. Each material was applied on the exposed pulp, and each cavity was subsequently restored with the resin composite. Rats were sacrificed 14 days after the surgical procedure. Serial stained sections were histologically evaluated for examining pulp tissue disorganization (PTD), inflammatory cell infiltration (ICI), dentin bridge formation (DBF), and bacterial penetration (BP). We found that rat pulps, which were direct capped with all-in-one adhesives, showed various degrees of PTD, ICI, and DBF depending on the material, and that there were no complete dentin bridges. In contrast, rat pulps capped with MTA showed no PTD and ICI, and there were complete dentin bridges in all, but one specimen. No BP was observed in any specimen.

Shear bond strengths of tooth coating materials including the experimental materials contained various amounts of multi-ion releasing fillers and their effects for preventing dentin demineralization.

We examined shear bond strengths (SBSs) of various tooth-coating-materials including the experimental materials to dentin and demineralization resistance of a fractured adhesive surface after the SBS testing. Three resin-type tooth-coating-materials (BC, PRG Barrier Coat; HC, Hybrid Coat II; and SF, Shield force plus) and two glass-ionomer-type tooth-coating-materials (CV, Clinpro XT Varnish; and FJ, Fuji VII) were selected. The experimental PRG Barrier Coat containing 0, 17, and 33 wt% S-PRG filler (BC0, BC17, and BC33, respectively) were developed. Each tooth-coating-material was applied to flattened dentin surfaces of extracted human teeth for SBS testing. After storing in water for 32 days with 4000 thermal cycling, the specimens were subjected to the SBS test. Specimens after SBS testing were subjected to a pH cycling test, and then, demineralization depths were measured using a polarized-light microscope. ANOVA and Tukey's HSD test were used for statistical analysis. The SBS value of FJ and CV was significantly lower than those of other materials except for BC (p < 0.01). The lesion depth of FJ was significantly shallower than those of other materials (p < 0.01); that of CV was significantly shallower than those of BC, HC, SF, and the control; and those of BC0 and BC17 were significantly shallower than that of the control (p < 0.05). The resin-type tooth-coating-materials demonstrated significantly higher SBS for dentin than the glass-ionomer-type tooth-coating-materials; however, they were inferior to the glass ionomer-type tooth-coating-materials in regards to the acid resistance of the fractured adhesion surface.

Effect of adhesive system application for cavities prepared with erbium, chromium: yttrium scandium gallium garnet laser on rat dental pulp tissue.

We examined the effects of adhesive systems under study applied for a laser-cut cavity using an Er,Cr:YSGG laser on rat dental pulp at 24 h and 14 days postoperatively. Group 1, laser-cut cavities were treated with a self-etching-primer and bonding agent; group 2, pretreated with a phosphoric-acid, and then treated with a self-etching-primer and bonding agent; group 3, pretreated with a phosphoric-acid and sodium-hypochlorite, and then treated with a self-etching-primer and bonding agent; and group 4, treated with an all-in-one adhesive. A flowable resin composite was used as filling material for each cavity treated with each group. A glass-ionomer-cement was used as a control. The following items were evaluated: pulp-tissue-disorganization (PTD), inflammatory-cell-infiltration (ICI), tertiary-dentin-formation (TDF), and bacterial-penetration (BP). The results were statistically analyzed using the Kruskal-Wallis test and Mann-Whitney U test. No significant differences were observed among the experimental groups for all parameters after 24 h and 14 days (P > 0.05). The majority of the specimens showed PTD with edema formation after 24 h; however, all the specimens demonstrated pulpal healing with TDF after 14 days. On the parameter of TDF, all groups showed significant differences between the two postoperative periods (P < 0.01). On the parameter of ICI, a significant difference was found between the two postoperative periods in group 4 (P < 0.05). No specimens showed BP. The pretreatment on the cavity prepared with the laser using phosphoric-acid or sodium-hypochlorite did not affect the dental pulp healing of rat tooth.

Effect of an experimental adhesive resin containing multi-ion releasing fillers on direct pulp-capping.

The purpose of this study was to evaluate pulpal healing and reparative dentin formation after 14 and 28 days in exposed rat pulp directly capped with an experimentally developed all-in-one adhesive containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler. The four experimental groups and the control group were compared using the Kruskal-Wallis test, followed by the Steel-Dwass post-hoc test to compare the histopathological score. The Mann-Whitney U test was used to compare the histopathological score at 14 and 28 days for each observation item. All experimental adhesives containing S-PRG fillers developed for direct pulp capping showed no pulpal inflammation. After 14 days, the experimental adhesives containing S-PRG fillers and the control group formed tertiary dentin around the exposed pulp. After 28 days, the experimental adhesives containing 13 and 27 wt% of S-PRG fillers formed dentin bridge equal to the control.

In vitro wear of flowable resin composite for posterior restorations.

The purpose of this study was to examine three- and two-body wear values of flowable resin composites for posterior restorations, using a mechanical loading device. The cavities prepared on flattened extracted molars were restored with flowable resin composites (Clearfil Majesty LV: MLV, Estelite Flow Quick: EFQ, Beautifil Flow Plus F00: BFP, and MI Fill: MIF) using accompanying adhesive systems. A universal resin composite (Clearfil Majesty) was used as a control. The specimens were subjected to in vitro three- and two-body wear testing. MLV showed high wear value (three-body: 14.69 µm, two-body: 0.268 mm(3)) compared with other materials tested in both three- and two-body wear tests. BFP showed high three-body wear value (5.78 µm), whereas low two-body wear value (0.008 mm(3)). MIF and EFQ showed equivalent wear values (MIF, three-body: 0.42 µm, two-body: 0.026 mm(3); EFQ, three-body: 1.15 µm, two-body: 0.14 mm(3)) to that of the control in both wear tests.

Histological evaluation of direct pulp capping of rat pulp with experimentally developed low-viscosity adhesives containing reparative dentin-promoting agents.

OBJECTIVES: This study examines the wound healing process in exposed rat pulp when capped with experimental adhesive resin systems. METHODS: Experimental adhesive resin system for direct pulp capping was composed of primer-I (PI), -II (PII), and -III (PIII) and an experimental bonding agent (EBA). PI was Clearfil(®) SE Bond(®)/Primer (CSP) containing 5.0 wt% CaCl2, PII was PI containing 10 wt% nanofiller (Aerosil(®) 380), and PIII was CSP containing 5.0 wt% of compounds of equal moles of synthetic peptides (pA and pB) derived from dentin matrix protein 1. EBA was Clearfil(®) SE Bond(®)/Bond (CSB) containing 10 wt% hydroxyapatite powders. Three experimental groups were designed. PI was assigned to experimental Groups 1 and 3. PII was assigned to experimental Groups 2 and 3. PIII and EBA were assigned to all experimental adhesive groups. Control teeth were capped with calcium hydroxide preparation (Dycal(®)), and CSP and CSB were applied to the cavity. The rats were sacrificed after each observation period (14, 28, 56, and 112 days). The following parameters were evaluated: pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation (RDF), and bacterial penetration. RESULTS: There were no significant differences among all the groups for all parameters and all observation periods (p>0.05, Kruskal-Wallis test). All groups showed initial RDF at 14 days postoperatively and extensive RDF until 112 days postoperatively. Groups 2 and 3 demonstrated higher quantity of mineralized dentin bridge formation compared with Group 1. CONCLUSIONS: Addition of nanofillers to the primer was effective in promoting high-density RDF. CLINICAL SIGNIFICANCE: Experimentally developed adhesive resin systems induce the exposed pulp to produce almost the same quantity of reparative dentin as calcium hydroxide. However, we need further studies to elucidate whether the same results could be obtained in humans.

The effect of multi-ion releasing filler contents on the dentin bond strength of an adhesive resin developed for direct pulp-capping.

We aimed to evaluate the microtensile bond strength (µTBS) of experimentally developed all-in-one adhesives containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler as a direct pulp-capping agent. Flattened dentin surfaces of extracted human molars were treated with four experimental adhesives of different S-PRG filler content (group 1: 0 wt%, group 2: 13 wt%, group 3: 27 wt% and group 4: 40 wt%) and Fluorobond Shakeone as the control. The beam samples were made and attached to the testing device, placed onto the tabletop-material-tester, and subjected to µTBS test. The data were statistically analyzed using one-way ANOVA. The results demonstrated that the µTBS value of group 2 was significantly lower than that of the control. No other significant differences among the µTBS values of groups and control were observed. It was concluded that the µTBS values of the experimental adhesives were not affected by the S-PRG filler contents except in group 2.

Bond strength of composite resin to enamel and dentin prepared with Er,Cr:YSGG laser.

We aimed to examine the effect of various adhesive systems on the bond strength of composite resin to enamel or dentin prepared with erbium, chromium: yttrium scandium gallium garnet (Er,Cr:YSGG) laser. Each laser-cut enamel or dentin surface was treated with a bonding agent (SBB, Group 1); self-etching primer (SBP) and SBB (Group 2 and control); phosphoric-acid (KET), SBP and SBB (Group 3); KET, sodium-hypochlorite (ADG), SBP and SBB (Group 4); all-in-one adhesive (TSB, Group 5); or KET, ADG and TSB (Group 6). The control group was only polished with wet silicon carbide papers. The enamel shear bond strength of Group 5 was significantly lower than that of other groups (p<0.01). The control group showed higher bond strength compared to Groups 1-6 (p<0.05). Preconditioning using phosphoric acid or phosphoric acid followed by sodium hypochlorite increased the bond strength of composite resin to enamel and dentin prepared using an Er,Cr:YSGG laser.