OBJECTIVES: To evaluate the effect of various toothpaste tablets on gloss and surface roughness of resin-based composite. METHODS AND MATERIALS: Sixty-four resin-based composite specimens were divided into four groups of...OBJECTIVES: To evaluate the effect of various toothpaste tablets on gloss and surface roughness of resin-based composite. METHODS AND MATERIALS: Sixty-four resin-based composite specimens were divided into four groups of 16 specimens each. Gloss and roughness were measured before and after simulated brushing with three types of toothpaste tablets and one conventional toothpaste: CT: Chewtab Toothpaste Tablets; AT: Anticavity Toothpaste Tablets; HC: Charcoal Toothpaste Tablets; CP: Cavity Protection toothpaste. The Kruskal-- Wallis procedure was performed to compare the differences by groups. Post-hoc comparisons were conducted with Bonferroni corrections (α=0.05). RESULTS: There was a significant drop in gloss for all groups. CT and AT maintained the highest gloss with means of 81.6 GU and 74.1 GU, respectively. The lowest gloss of 24.5 GU was observed for HC. There was a significant increase in roughness for all groups except for CT. CT had the lowest roughness with a mean of 0.034 μm, while HC had the highest roughness with a mean of 0.074 μm. There was a significant correlation between post-brushing gloss and post-brushing roughness (p<0.001, r=-0.884). CONCLUSION: Chewtab Toothpaste Tablets had the least effect on gloss and roughness, while Charcoal Toothpaste Tablets had the most negative effect on the surface properties of resin-based composites.
PURPOSE: This study's purpose was to evaluate the effect of simulated in vitro hydrostatic pulpal pressure (HPP) on microleakage. METHODS AND MATERIALS: Extracted third molars (n=12) were sectioned 5 mm below the cemento...PURPOSE: This study's purpose was to evaluate the effect of simulated in vitro hydrostatic pulpal pressure (HPP) on microleakage. METHODS AND MATERIALS: Extracted third molars (n=12) were sectioned 5 mm below the cementoenamel junction, pulp tissue removed, and the sectioned crowns mounted on a Plexiglas plate penetrated by an 18-gauge stainless steel tube. The mounted specimen mesial surface received a 2×4×6 mm Class V preparation followed by restoration with a strongly acidic, one-step dental adhesive and a flowable microfilled resin, following all manufacturers' instructions. Restorations were finished to contour, and tubing was attached to a 20-cm elevated, 0.2% rhodamine G reservoir to the specimen steel tube for 48 hours. Specimens then received a nail polish coating to within 1 mm of the restoration margins and were placed in 2% methylene blue (MB) dye for 24 hours, followed by rinsing, embedding in epoxy resin, and sectioning into 1 mm slices using a diamond saw. Controls were intact molars (n=12) processed as above but without HPP. Specimen slices were evaluated using laser confocal microscopy with images exported to ImageJ software with microleakage assessed as the MB linear penetration as a percentage of the total interfacial wall length. Mean values were evaluated with the Kruskal Wallis/Dunn test at a 95% confidence level. RESULTS: The control specimens demonstrated significantly greater (p<0.0001) MB penetration than experimental specimens with simulated HPP. Under this study's conditions, simulated HPP significantly decreased MB dye penetration. CONCLUSION: Studies accomplished without simulated HPP may overestimate microleakage results.
OBJECTIVES: To investigate the influence of filler type/loading on the micro-tensile fracture strength (μTFS) of adhesive resins, as measured 'immediately' upon preparation and after 1-week water storage ('water-stored')...OBJECTIVES: To investigate the influence of filler type/loading on the micro-tensile fracture strength (μTFS) of adhesive resins, as measured 'immediately' upon preparation and after 1-week water storage ('water-stored'). METHODS: The morphology and particle-size distribution of three filler particles, referred to as 'Glass-S' (Esschem Europe), 'BioUnion' (GC), and 'CPC_Mont', were correlatively characterized by SEM, TEM, and particle-size analysis. These filler particles were incorporated into an unfilled adhesive resin ('BZF-29unfilled', GC) in different concentrations to measure the 'immediate' μTFS. After 1-week water storage, the 'water-stored' μTFS of the experimental particle-filled adhesive resins with the most optimum filler loading, specific for each filler type, was measured. In addition, the immediate and water-stored μTFS of the adhesive resins of three experimental two-step universal adhesives based on the same resin matrix but varying for filler type/loading, coded as 'BZF-21' (containing silica and bioglass), 'BZF-29' (containing solely silica), and 'BZF-29_hv' (highly viscous with a higher silica loading than BZF-29), and of the adhesive resins of the gold-standard adhesives OptiBond FL ('Opti-FL', Kerr) and Clearfil SE Bond 2 ('C-SE2', Kuraray Noritake) was measured along with that of BZF-29unfilled (GC) serving as control/reference. Statistics involved one-way and two-way ANOVA followed by post-hoc multiple comparisons (α<0.05). RESULTS: Glass-S, BioUnion, and CPC_Mont represent irregular fillers with an average particle size of 8.5-9.9 μm. Adding filler to BZF-29unfilled decreased μTFS regardless of filler type/loading. One-week water storage reduced μTFS of all adhesive resins except BZF-21, with the largest reduction in μTFS recorded for BZF-29unfilled. Among the three filler types, the μTFS of the 30 wt% Glass-S and 20 wt% BioUnion filled adhesive resin was not significantly different from the μTFS of BZF-29unfilled upon water storage. CONCLUSIONS: Adding filler particles into adhesive resin did not enhance its micro-tensile fracture strength but appeared to render it less sensitive to water storage as compared to the unfilled adhesive resin investigated.
When restoring anterior teeth using resin composites, the use of silicone guide matrices obtained from diagnostic wax-ups is recommended, as this technique facilitates layering and optimizes working time. This is particu...When restoring anterior teeth using resin composites, the use of silicone guide matrices obtained from diagnostic wax-ups is recommended, as this technique facilitates layering and optimizes working time. This is particularly important in polychromatic layering and when more than one anterior tooth is to be restored with resin composites. However, in cases of fractured anterior teeth, it is often not feasible to perform a previous impression and waxing. In these cases, due to trauma and related psychological aspects, patients usually seek immediate esthetic solutions. Therefore, an interesting restorative approach that can simplify the restorative technique is the creation of a silicone guide matrix obtained from the patient's fractured tooth, without the need for prior waxing. This type of personalized matrix was initially proposed by Bertholdo, Ricci, and Barrote. Thus, the purpose of the present work is to demonstrate a modification of the technique for making this type of custom-made matrix for the restoration of two upper central incisors of a 14-year-old patient who fractured his teeth in a bicycle accident.
OBJECTIVES: This study aimed to investigate bond performance of various resin luting cement (RLC) systems on enamel and dentin in different etching modes and to compare the RLC-tooth interface morphology using scanning e...OBJECTIVES: This study aimed to investigate bond performance of various resin luting cement (RLC) systems on enamel and dentin in different etching modes and to compare the RLC-tooth interface morphology using scanning electron microscopy (SEM). METHODS AND MATERIALS: The self-adhesive RLC systems used in combination with universal adhesives were as follows: Scotchbond Universal Adhesive Plus + RelyX Universal (3M Oral Care) and Clearfil Universal Bond Quick ER + SA Luting Multi (Kuraray Noritake Dental). These RLC systems were also used alone as self-adhesive RLC systems without universal adhesives (self-adhesive mode). The conventional RLC systems for comparison materials were as follows: BeautiBond Xtream + ResiCem EX (Shofu) and Tooth Primer + Panavia V5 (Kuraray Noritake Dental). Twelve specimens were prepared for each group to measure shear bond strength (SBS) in different etching modes. A stainless-steel rod was used as a substitute for indirect restorations. Bonded specimens were allocated to baseline (stored for 24 hours) and artificially aged (thermocycling [TC] for 10,000 cycles) groups. Representative treated tooth surfaces and RLC-tooth interfaces were observed using SEM. RESULTS: Three-way analysis of variance (ANOVA) revealed that all the factors (etching mode, storage period, and RLC system) had a significant influence on the enamel SBS values (p<0.05). Enamel SBS was significantly higher in etch-&-rinse (ER) mode than in self-etch (SE) mode, regardless of RLC system or storage period. Three-way ANOVA showed that all the factors had a significant influence on the dentin SBS values (p<0.001). Most RLC systems showed significantly higher dentin SBS in SE mode than in ER mode, regardless of storage period. However, the combination with Scotchbond Universal Adhesive Plus and RelyX Universal showed no significant difference in SBS values between etching modes at the baseline and showed a significantly higher SBS value in ER mode than in SE mode after TC. CONCLUSIONS: The self-adhesive RLC systems with universal adhesives tended to show higher enamel and dentin bond performance than the self-adhesive RLC systems alone. The morphology of treated tooth surfaces and resin cement-tooth interfaces were dependent on the RLC system and etching mode used. The RLC systems with primer application showed a thin, high-density layer above the intact dentin in both etching modes, suggesting chemical interaction.
The study aimed to evaluate the effect of thickness on the translucency parameter (TP) and whiteness index for dentistry (WID) of single-shade resin composites compared with a multi-shade resin composite after thermocycl...The study aimed to evaluate the effect of thickness on the translucency parameter (TP) and whiteness index for dentistry (WID) of single-shade resin composites compared with a multi-shade resin composite after thermocycling. A total of 100 resin composite samples of five brands (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma, and Charisma Diamond One) with thicknesses of 2 mm and 4 mm were prepared (n=10). CIE L*a*b* coordinates were obtained using a spectrophotometer. The resin composite samples were subjected to 10,000 thermocycles. Before and after thermocycling, TP values were calculated with the CIEDE2000 formula, and whiteness values were calculated using the WID. The influence of thickness, resin composite, and aging on these variables was analyzed using the generalized linear model (p<0.05). Omnichroma and Filtek Z250 exhibited, respectively, the highest and the lowest TP00 values compared with the other resin materials (p<0.001). The TP00 values of Zenchroma and Diamond One were similar (p>0.05). Vittra APS Unique had a lower TP than Zenchroma and Diamond One (p<0.001). Before thermocycling, the highest WID showed the combination of Vittra APS Unique with thicknesses of 2 mm (48.33±1.18). After thermocycling, the highest WID was shown in the combination of Vittra APS Unique with thicknesses of 2 mm (45.33±0.55) and 4 mm (46.23±0.94) (p<0.001). After thermocycling, the lowest WID was for the combination of Filtek Z250 with thicknesses 2 mm (21.16±0.93) and 4 mm (20.70±0.91) (p<0.001). The TP and WID values of the resin composites varied across different composites and thicknesses. Single-shade resin composites of different thicknesses demonstrated higher translucency and whiteness values than multi-shade resin composite, both before and after thermocycling.
PURPOSE: This study aimed to evaluate the effects of two desensitizers and the Er,Cr:YSGG laser on human dentin tubules, applied alone or in combination. METHODS: Ninety-six dentin specimens were obtained from extracted...PURPOSE: This study aimed to evaluate the effects of two desensitizers and the Er,Cr:YSGG laser on human dentin tubules, applied alone or in combination. METHODS: Ninety-six dentin specimens were obtained from extracted third molars and divided into six groups: Group 1: no-treatment (Control); Group 2: nano-hydroxyapatite desensitizer (NhapD); Group 3: NhapD+Er,Cr:YSGG laser (L); Group 4: Er,Cr:YSGG laser (L); Group 5: glutaraldehyde desensitizer (GD); and Group 6: GD+L, respectively. All specimens were evaluated using scanning electron microscopy. The diameter and the number of open dentin tubules, the tubules' occluding ratio, and the mineral coverage area were measured via the Image J software at 2000× magnification. Atomic force microscopy was used to determine the blocking mechanism of desensitizing treatments and the surface morphology of dentin specimens. One-way ANOVA and Tukey tests were used for statistical analysis. RESULTS: The number of open tubules and the mean diameter of tubules for all treatment groups showed statistically significant differences from the control group The NhapD+L group had a significantly lower number of open tubules than the L and GD groups. The NhapD+L and L groups significantly had higher occluding ratios than the other groups. CONCLUSIONS: The present study showed that the Er,Cr:YSGG laser alone was effective in terms of tubule occlusion and also contributed to increasing the occluding ratio of nano-hydroxyapatite. It may be recommended to use the Er,Cr:YSGG laser with nano-hydroxyapatite desensitizers to achieve effective tubule occlusion.
The aim of this study was to evaluate the push-out bond strength and the failure mode of single adjustable posts (SPLENDOR SAP), anatomical posts (AP), or computer-aided design/computer-aided manufacturing (CAD-CAM) post...The aim of this study was to evaluate the push-out bond strength and the failure mode of single adjustable posts (SPLENDOR SAP), anatomical posts (AP), or computer-aided design/computer-aided manufacturing (CAD-CAM) posts cemented to flared root canal dentin with self-adhesive dual-cure resin cement. Thirty single-rooted premolars received endodontic treatment with gutta-percha and a calcium hydroxide-based endodontic cement. After 24 hours, the canal spaces were enlarged with burs. The tooth specimens were divided equally into three groups (n=10), according to the glass fiber post (GFP) system: AP-prefabricated GFP (Reforpost #2, Angelus) was relined with composite resin (Filtek Z350 XT, 3M ESPE); SPLENDOR SAP-GFP was used with a glass fiber sleeve to adjust the adaptation (Splendor SAP, Angelus); and CAD-CAM-a resin pattern was obtained and scanned to produce a CAD-CAM GFP (Fiber CAD Lab, Angelus) milled using a subtractive technique. The three GFP systems were cemented with self-adhesive resin cement (Rely X U200, 3M ESPE). The roots were fixed to an acrylic resin plate used to section them into specimens of cervical, middle, and apical thirds. Then, the slices were attached to a universal testing machine to perform the push- out test at a speed of 0.5 mm/min and a load of 50 Kgf. The posttest specimens were examined under a stereoscopic microscope to evaluate the failure mode. The bond strength variable was analyzed using a generalized linear model, following a split-plot design. Failure mode analysis was performed using Fisher exact test. The significance level adopted was 5%. There was no significant difference among the GFP systems or among the thirds, in terms of bond strength (p>0.05), nor was there any significant association between the systems and the failure mode (p>0.05). Most specimens presented mixed or adhesive failure between resin cement and dentin. It was concluded that the bond strength to flared root dentin was not influenced by the GFP system or the root third.
OBJECTIVES: To evaluate the effect of the different radiant exposures from a multipeak light curing unit on the physical and mechanical properties of flowable and high-viscosity bulk-fill resin-based composites (RBC). ME...OBJECTIVES: To evaluate the effect of the different radiant exposures from a multipeak light curing unit on the physical and mechanical properties of flowable and high-viscosity bulk-fill resin-based composites (RBC). METHODS: Five flowable bulk-fill RBCs (Tetric N-Flow Bulk-fill, Ivoclar Vivadent; Filtek Bulk Fill Flow, 3M Oral Care; Opus Bulk Fill Flow APS, FGM; Admira Fusion x-base, Voco and; and SDR Plus Bulk Fill Flowable, Dentsply Sirona) and five high-viscosity bulk-fill RBCs (Tetric N-Ceram Bulk-fill, Ivoclar Vivadent; Filtek One Bulk Fill, 3M Oral Care; Opus Bulk Fill APS, FGM; Admira Fusion x-tra, Voco; and SonicFill 2, Kerr) were photo-cured using a VALO Cordless light (Ultradent) for 10, 20, and 40 seconds at an irradiance of 1200, 800, or 400 mW/cm2, resulting in the delivery of 4, 8, 12, 16, 24, 32, or 48 J/cm2. Post-gel shrinkage (Shr) was calculated using strain-gauge test. The degree of conversion (DC, %) was calculated using FTIR. Knoop hardness (KH, N/mm2) and elastic modulus (E, MPa) were measured at the top and bottom surfaces. Logarithmic regressions between the radiant exposures and mechanical properties were calculated. Radiodensity was calculated using digital radiographs. Data of Shr and radiodensity were analyzed using two-way analysis of variance (ANOVA), and the DC, KH, and E data were analyzed with two-way ANOVA using split-plot repeated measurement tests followed by the Tukey test (a = 0.05). RESULTS: Delivering higher radiant exposures produced higher Shr values (p<0.001) and higher DC values (R2=0.808-0.922; R2=0.648-0.914, p<0.001), KH (R2=0.707-0.952; R2=0.738-0.919; p<0.001), and E (R2=0.501-0.925; R2=0.823-0.919; p<0.001) values for the flowable and high-viscosity RBCs respectively. Lower KH, E and Shr were observed for the flowable bulk-fill RBCs. All bulk-fill RBCs had a radiopacity level greater than the 4-mm thick aluminum step wedge. The radiant exposure did not affect the radiopacity. CONCLUSION: The Shr, DC, KH, and E values were highly correlated to the radiant exposure delivered to the RBCs. The combination of the higher irradiance for longer exposure time that resulted in radiant exposure between 24 J/cm2 to 48 J/cm2 produced better results than delivering 400 mW/cm2 for 40 s (16 J/cm2), and 800 mW/cm2 for 20 seconds (16 J/cm2) or 1200 mW/cm2 for 10 seconds (12 J/cm2). All the bulk-fill RBCs were sufficiently radiopaque compared to 4 mm of aluminum.
OBJECTIVES: To evaluate the volume and depth of enamel loss promoted by 37.5% and 7.5% hydrogen peroxide (HP) gels, and quantify the loss of calcium (Ca) and phosphate (P) ions by using ion chromatography (IC) analysis a...OBJECTIVES: To evaluate the volume and depth of enamel loss promoted by 37.5% and 7.5% hydrogen peroxide (HP) gels, and quantify the loss of calcium (Ca) and phosphate (P) ions by using ion chromatography (IC) analysis after bleaching. METHODS: Sixty bovine enamel specimens were randomly divided into three groups: Control - no bleaching gel; HP37.5%, application of HP 37.5% for 45 minutes for 14 days; and HP7.5%, application of HP 7.5% for 3 applications of 8 minutes. The surface analysis (n=5) was performed using a scanning electron microscope (SEM) and dispersive energy system (EDS) to calcium and phosphorus dosage. The micro-CT was used for the enamel loss analysis (n=5). IC was used to analyze extracted Ca and P (n=10). Data were analyzed by one-way ANOVA and two-way repeated measures ANOVA, followed by Tukey and Dunnett's tests (α=0.05). RESULTS: Significantly higher volume and depth of enamel loss were found for bleached groups compared with the control group. HP7.5% had significantly higher enamel change than HP37.5%. SEM showed higher enamel porosity for HP37.5% and HP7.5% compared to control. The IC demonstrated a significant increase of Ca incorporated into the gel, however, only HP7.5% had a higher P presence than the control group. The HP7.5% showed higher Ca and P ion exchange than HP37.5% (p<0.001). CONCLUSION: HP37.5% and HP7.5%, caused enamel mineral changes compared with the control group. The IC method was demonstrated to be an effective methodology for detecting enamel mineral loss by the bleaching gel.
OBJECTIVES: This study aimed to evaluate the optical and mechanical performance of two single-shade resin-based composites (RBCs) compared to those of a conventional RBC for restoring posterior teeth. METHODS: Two single...OBJECTIVES: This study aimed to evaluate the optical and mechanical performance of two single-shade resin-based composites (RBCs) compared to those of a conventional RBC for restoring posterior teeth. METHODS: Two single-shade RBCs, Omnichroma (Tukoyama) and Vittra Unique APS (FGM), and a conventional RBC, Filtek Z350XT shade A2 (3M Oral Care), were evaluated in this study. The optical shade-matching performance was measured using a spectrophotometer. The light emitted by VALO Grand (Ultradent) and transmitted through the 2.0-mm RBC specimens was evaluated using beam profiling. Knoop hardness (KH, N/mm2), degree of conversion (DC, %) at the top and bottom, flexural strength (FS, MPa), elastic modulus (E, GPa), postgel shrinkage (Shr, %), and shrinkage stress (MPa) were evaluated. Scanning electron microscopy (SEM) was used to characterize the filler. Data for FS, E, and Shr were analyzed by one-way analysis of variance (ANOVA) and KH and DC by repeated one-way ANOVA measurement followed by Tukey test (α=0.05). The modified von Mises stress values, light transmission, and SEM images were analyzed qualitatively. RESULTS: All single-shade RBCs exhibited higher chromatic adaptation than the Filtek Z350XT (p<0.001). Omnichroma exhibited less color difference than Vittra Unique APS, irrespective of the shade. The light transmitted through Omnichroma and Vittra Unique APS increased during polymerization. KH and DC values were significantly reduced from the top to the bottom of the specimens for all RBCs (p<0.001); however, the ratio values were always higher than 80%. In general, all RBCs demonstrated similar mechanical properties. All RBCs exhibited a similar FS (p=0.083) and Shr value (p=0.144). Filtek Z350XT exhibited significantly higher E (p<0.001) than both single-shade RBCs. All RBCs exhibited similar shrinkage stress during restoration and similar residual stress during occlusal loading. CONCLUSIONS: Single-shade Omnichroma and Vittra Unique APS increased light transmission during light-activation, demonstrating better chromatic adaptation than conventional Filtek Z350XT. In general, Omnichroma and Vittra Unique APS exhibited similar mechanical properties and shrinkage stress distributions as Filtek Z350XT during light-activation and occlusal loading.
This study evaluated the fracture resistance of teeth with mesio-occluso-distal (MOD) resin composite restorations using universal adhesive (Single Bond Universal; SBU) in three different manipulation modes compared with...This study evaluated the fracture resistance of teeth with mesio-occluso-distal (MOD) resin composite restorations using universal adhesive (Single Bond Universal; SBU) in three different manipulation modes compared with those using two-step self-etch (Clearfil SE bond; CSE) and 3-step etch-and-rinse (Scotchbond Multi-Purpose; SBMP) adhesives at 24 hours and after thermocycling. One hundred and sixty maxillary premolars were assigned into eight groups of 20 each. Intact teeth and nonrestored cavity-prepared teeth served as controls. For the remaining specimens, cavities were restored with resin composite using different adhesives-SBU in self-etch, etch-and-rinse, or selective enamel etching modes; CSE in self-etch or selective enamel etching; and SBMP. Specimens from each group were either stored in 37°C water for 24 hours or further submitted to thermocycling for 30,000 cycles (n=10), then subjected to axial compression stress until fracture. Fracture patterns were observed microscopically. Data were statistically analyzed at a 95% confidence level. Among the restored teeth, mean failure load of the group using SBMP was the highest at both short-term and long-term evaluation periods (p<0.05). Fracture strengths of the SBU groups where enamel was etched with phosphoric acid prior to the adhesive application were similar and were greater than in those specimens without pre-etching (p<0.05). After thermal aging, a significant decrease in fracture resistance value was detected only for the group using SBU in etch-and-rinse application mode (p<0.05). For the self-etch strategy, SBU demonstrated lower load to fracture than CSE following thermocycling; all specimens failed at and beneath the crestal level (p<0.05). Application of SBU universal adhesive in selective enamel etching mode provided higher and more stable fracture resistance of teeth with MOD resin composite restorations than in self-etch mode.
This study examined the influence of cariogenic environments on the surface roughness of ion-releasing restorative materials (IRMs). Custom-made stainless steel molds with holes of 5 mm × 2mm were used to fabricate 60 di...This study examined the influence of cariogenic environments on the surface roughness of ion-releasing restorative materials (IRMs). Custom-made stainless steel molds with holes of 5 mm × 2mm were used to fabricate 60 disc-shaped specimens of each of the following materials: Activa Bioactive (AV), Beautifil Bulk Restorative (BB), Cention N (Bulk-fill) (CN), and Filtek Z350XT (FZ) (Control). Baseline surface roughness (Ra) measurements were obtained using an optical 3D measurement machine (Alicona Imaging GmbH, Graz, Austria). The specimens were then randomly divided into five subgroups (n=12) and exposed to 10 ml of the following mediums at 37°C: distilled water (DW), demineralization solution (DM), remineralization solution (RM), pH cycling (PC) and air (AR) (control). Ra measurements were again recorded after one week and one month, followed by statistical evaluations with two-way analysis of variance (ANOVA) to determine interactions between materials and mediums. One-way ANOVA and post hoc Games Howell tests were performed for intergroup comparisons at a significance level of 0.05. Mean Ra values ranged from 0.085 ± 0.004 (µm) to 0.198 ± 0.001 µm for the various material-medium combinations. All IRMs showed significant differences in Ra values after exposure to the aqueous mediums. The smoothest surfaces were observed in the AR for all materials. When comparing materials, AV presented the roughest surfaces for all mediums. All IRM materials showed increased surface roughness over time in all cariogenic environments but were below the threshold value for bacterial adhesion, except for AV 1-month post immersion with pH cycling. Therefore, besides AV, the surface roughness of IRMs did not deteriorate to an extent that it is clinically relevant.
OBJECTIVES: This study was designed to: 1) evaluate and compare the evidence-practice gap (EPG) in minimal intervention dentistry (MID) in Japan and Brazil by measuring concordance between dentists' clinical practice and...OBJECTIVES: This study was designed to: 1) evaluate and compare the evidence-practice gap (EPG) in minimal intervention dentistry (MID) in Japan and Brazil by measuring concordance between dentists' clinical practice and published evidence; and 2) identify dentists' factors associated with the EPG in both countries. METHODS: We performed a cross-sectional study using a web-delivered questionnaire among 136 Japanese and 110 Brazilian dentists. The questionnaire consisted of three questions concerning "restoration diagnosis and treatment," "deep caries diagnosis and treatment," and "caries risk assessment" regarding MID. A chi-square test was used to analyze differences in concordance among clinical practice and evidence from the literature between Japanese and Brazilian dentists. Logistic regression analyses were performed to analyze dentists' factors associated with overall concordance for all three questions. RESULTS: Overall concordance was significantly higher in Brazil (55%) than in Japan (38%) (p<0.01). Concerning how evidence was obtained, textbooks, nonacademic journals, and seminars and workshops were used as information sources more frequently by Japanese than Brazilian dentists (p<0.001), whereas scientific journal articles in English were used more frequently by Brazilian dentists (p<0.001). On logistic regression analysis, overall concordance was higher for Japanese dentists who frequently obtained evidence from scientific journal articles in English (p<0.05), whereas Brazilian dentists who frequently obtained evidence from the Internet were associated with lower overall concordance (p<0.05). CONCLUSIONS: Because overall concordance was significantly higher in Brazil than in Japan, Japan may have a greater EPG in MID practice. Specific characteristics of Japanese and Brazilian dentists showed significant associations with overall concordance.
OBJECTIVES: This study aimed to investigate the effect of manual coloring of blank monolithic zirconia blocks of four materials on their shade reproducibility, flexural strength, and surface roughness as compared with pr...OBJECTIVES: This study aimed to investigate the effect of manual coloring of blank monolithic zirconia blocks of four materials on their shade reproducibility, flexural strength, and surface roughness as compared with preshaded blocks of the same material. METHODS AND MATERIALS: Eight disc-shaped specimens (diameter=12mm; height=2mm) and eight bar-shaped specimens (25×2×2 mm) were milled from the shaded and non-shaded blocks of the four zirconia systems: Ceramill, Kerox, White Peaks, and Dental Direkt. In total, 128 specimens were fabricated. The non-shaded specimens of each system were coloured according to A2 shade. The surface roughness (Ra) was measured using a contact profilometer. Color difference was calculated according to the CIEDE2000 formula. The bar-shaped specimens were loaded to fracture following three-point bend testing at 1 mm/minute crosshead speed. Data were analysed following one-way analysis of variance (ANOVA), and the Tukey post-hoc test (p=0.05). RESULTS: Manual-coloring affected the surface roughness, color difference, and flexural strength of three materials in comparison to their preshaded blocks (p<0.05). White Peaks was not affected (p>0.05). Ra values ranged from 1.1-1.9; three materials were not affected (p>0.05). Kerox preshaded blocks were the smoothest (p<0.05) but became the roughest once colored (p<0.05). White Peaks and Dental Direkt materials had preshaded blocks matching the A2 guide-tab (p>0.05). DE was perceptible and unacceptable for the preshaded and manually shaded blocks of all materials tested (ΔE>1.8). While manual coloring reduced flexural strength of Ceramill and Dental Direkt (p<0.05), flexural strength was retained by Kerox and White Peaks (p>0.05). CONCLUSIONS: White Peaks was not affected by the coloring technique. Coloring had negative effects on Ceramill flexural strength and color reproducibility.
This non-controlled clinical study evaluated the masking effect of an infiltrant resin on mild molar incisor hypomineralization (MIH) lesions. Thirty MIH-affected anterior teeth with creamy/ white opacities from 12 child...This non-controlled clinical study evaluated the masking effect of an infiltrant resin on mild molar incisor hypomineralization (MIH) lesions. Thirty MIH-affected anterior teeth with creamy/ white opacities from 12 children aged 6-15 years received the application of an infiltrant resin (Icon- DMG). Standard photographs were taken before (T1), immediately after (T2), and 1 week after (T3) resin infiltration. Two calibrated examiners qualitatively analyzed the color match using the Fédération Dentaire Internationale (FDI) scale. The binomial distribution test analyzed the scores of the color match at T1 with T2 and T3, and McNemar's test analyzed the scores of the color match between T2 and T3 (α=0.05). There was a significant increase in color match between T1 and T2 (p=0.0005), between T1 and T3 (p=0.0005), and between T2 and T3 (p=0.0019). It was concluded that infiltrant resin was effective in improving the esthetic appearance of creamy/white opacities on MIH-affected anterior teeth.
The rise in temperature in pulp tissues is related not only to heat transfer by high-irradiance light-curing units (LCUs), but also to restorative procedures. This research aimed to compare the rise in pulp temperature (...The rise in temperature in pulp tissues is related not only to heat transfer by high-irradiance light-curing units (LCUs), but also to restorative procedures. This research aimed to compare the rise in pulp temperature (PT) induced by three LCUs at each restorative step while considering the influence of resin composite shade and thickness. To accomplish this, the investigators used a proposed experimental model replicating pulp fluid circulation with a controlled, simulated intraoral temperature in bovine incisors. The recorded external and internal PT ranged from 36.7°C to 37.1°C and 32.7°C to 33.0°C, respectively. A significant decrease of internal temperature was recorded during class V preparation, followed by a progressive and representative rise of temperature in the subsequent restorative steps. The temperature was significantly higher during light curing of the adhesive system using Valo compared to light curing using Elipar and Radii Cal. However, none of the analyzed devices produced a temperature that exceeded the pulp tolerance limit (a temperature increase over 5.5°C). The paired test showed no significant difference in pulp temperature associated with the thickness of the increment of resin composite. However, shade was found to have more influence on the amount of energy absorbed by pulp tissue-A1 samples showed significantly higher temperature variation compared to samples using the A4 shade of resin composite. To conclude, the microcirculation and the performance of procedures under constant air-water flux dissipate the heat absorbed by the pulp. Additionally, the data suggest that all three LCUs analyzed can be safely used in clinical procedures, and that the resin composite shade may influence the amount of irradiance delivered to the tooth surface and represents a significant factor in pulp temperature variance.
OBJECTIVES: The objective of this prospective double-blind clinical trial was to compare clinical outcomes of indirect pulp capping restorative protocols on permanent teeth over a 12-month period. METHODS AND MATERIALS:...OBJECTIVES: The objective of this prospective double-blind clinical trial was to compare clinical outcomes of indirect pulp capping restorative protocols on permanent teeth over a 12-month period. METHODS AND MATERIALS: Deep carious lesions in permanent teeth (90) were randomly assigned to three indirect pulp capping protocols (n=30: TheraCal LC, Dycal, and no liner). All teeth were restored with resin composite. The outcome measures were pain (VAS scale) and success rate (pulp vitality based on percussion, palpation, cold test, and radiographic findings), collected at screening, intervention, and 24-hour, 7-day, 3-month, 6-month, and 12-month follow-up visits. RESULTS: There was no statistically significant difference in tooth sensitivity among the three indirect pulp capping protocols nor in success rates among the restorative protocols after 1 year of follow-up (p>0.1).The respective success rates, as defined by the tooth remaining vital, after 1 year were: 96.2% for TheraCal LC, 100% for Dycal, and 100% for no liner. CONCLUSIONS: After 12-month evaluation, the success rate of indirect pulp capping therapy on permanent teeth was not affected by the pulp capping restorative protocol.