Niwut Juntavee | Khon Kaen University (original) (raw)

Papers by Niwut Juntavee

European Journal of Dentistry

Objectives Firing protocols influence optical properties of dental ceramics. Effects of varying c... more Objectives Firing protocols influence optical properties of dental ceramics. Effects of varying cooling rates of monochrome and multilayer 5 mol% yttria-stabilized tetragonal polycrystalline (5YTZP) on optical properties are subjected for investigation. Materials and Methods Ninety specimens (width, length, thickness = 10 × 20 × 2 mm) were prepared from monochrome (Mo: Cercon xt) and multilayer (Mu: Cercon xt ML with cervical (C) and incisal (I) zoning) 5YTZP. Specimens were sintered and randomly treated with three cooling rates (n = 15/group): slow (S: 5°C/min), normal (N: 35°C/min), and fast (F: 70°C/min). Color appearance (∆EW), color appearance difference (∆E diff), translucency parameter (TP), contrast ratio (CR), and opalescence parameter (OP) were evaluated in CIEL*a*b* (Commission International de I'Eclairage) system. ∆E diff was achieved from the coordinate difference of specimen to VITA classic shade A2. Microstructures and compositions were evaluated by scanning elect...

Journal of Dental Sciences

Clinical Oral Investigations

Journal of Prosthodontics

PurposeFiring protocols influence the mechanical properties of dental ceramics. This study examin... more PurposeFiring protocols influence the mechanical properties of dental ceramics. This study examined the impact of altering the cooling rate of mono‐ and multilayered 5 mol% yttria‐partially stabilized zirconia (5Y‐PSZ) on their strength.Materials and methodsNinety specimens (width × length × thickness = 10 × 20 × 2 mm) were prepared using 5Y‐PSZ monolayer (Mo: Cercon‐xt) and 5Y‐PSZ multilayered (Mu: Cercon‐xt ML) blocks. Randomly distributed specimens were sintered at the recommended firing schedule for three different categories of cooling rates (n = 15/group): slow (S: 5°C/min), normal (N: 35°C/min), and fast (F: 70°C/min). A universal testing machine with four‐point bending test was used to measure the flexural strength (σ). The microstructure, fracture characteristics, and chemical composition were evaluated by scanning electron microscope and energy‐dispersive spectroscopy. The monoclinic, tetragonal, and cubic phases were investigated using X‐ray diffraction. Two‐way ANOVA and...

Journal of Clinical and Experimental Dentistry, 2018

Background: Incompatible coefficient of thermal expansion (CTE) is supposed to be a reason for ch... more Background: Incompatible coefficient of thermal expansion (CTE) is supposed to be a reason for chipping of ceramic veneered zirconia. This study evaluates the effect of veneering ceramic at varied CTE on bond strength to zirconia. Material and Methods: Zirconia disks (Z, Ø 10 mm, 1.0 mm thickness) were prepared from Y-TZP (Cercon ®) and sintered at 1350°C for 6 hours. All zirconia disks were veneered with ceramics ((Ø 7.0 mm, 1.5 mm thickness) with varied CTE including VITADur ® alpha (VDα), VITAVM ® 7 (VM7), VITAVM ® 9 (VM9), Cercon ® ceramkiss (CCK), IPSe.max ® ceram (IeC), and IPS dSIGN ® (IdS) (n=15). The specimens were thermo-cycled (5-55 °C, 500 cycles) prior to determine the shear bond strength on a universal testing machine. The veneering ceramic and zirconia rods (Ø 4 mm, 30 mm length) were prepared for CTE evaluation. ANOVA and Tukey's multiple comparisons were used to determine the statistically significant difference (α=0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristics strength (σ o) of the shear bond. The interfaces were microscopically examined. The phase transformation of zirconia was determined using X ray diffraction.

The Scientific World Journal, Oct 6, 2021

Introduction. High-translucence ceramics have been used increasingly. is study evaluated the biax... more Introduction. High-translucence ceramics have been used increasingly. is study evaluated the biaxial flexural strength of different ceramics as a result of varying thicknesses. Materials and Methods. Circular discs with varied thickness of 0.4

Journal of Clinical and Experimental Dentistry, 2018

Shear bond strength of ceramic bracket bonded to different surface-treated ceramic e1167

The journal of contemporary dental practice, 2018

Aim: This study evaluated the effect of light-emitting diode (LED) illumination bleaching techniq... more Aim: This study evaluated the effect of light-emitting diode (LED) illumination bleaching technique on the surface nanohardness of various computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic materials. Materials and methods: Twenty disk-shaped samples (width, length, and thickness = 10, 15, and 2 mm) were prepared from each of the ceramic materials for CAD/CAM, including Lava™ Ultimate (L V), Vita Enamic ® (E n) IPS e.max ® CAD (M e), inCoris ® TZI (I C), and Prettau ® zirconia (P r). The samples from each type of ceramic were randomly divided into two groups based on the different bleaching techniques to be used on them, using 35% hydrogen peroxide with and without LED illumination. The ceramic disk samples were bleached according to the manufacturer's instruction. Surface hardness test was performed before and after bleaching using nanohardness tester with a Berkovich diamond indenter. Results: The respective Vickers hardness number upon no bleaching and bleaching without or with LED illumination [mean ± standard deviation (SD)] for each type of ceramic were as follows: 102.

Orthodontic Waves, Sep 1, 2008

Bonding orthodontic buccal tube on a large resin composite restoration of molar tooth can result ... more Bonding orthodontic buccal tube on a large resin composite restoration of molar tooth can result in easier bond failure than bonding to intact enamel. The resin composite type may be one of several factors that influence the bond strength. The objective of this study was to analyze the survival probabilities of buccal tubes bonded to various resin composites. Resin composite discs, 33 specimens for each group were prepared as follows: (1) nanofill (Filtek Supreme), (2) compomer (F2000), (3) hybrid (Z100), (4) packable (P60) and (5) flowable (Filtek Flow). The surface was etched with 9.6% hydrofluoric acid, followed by plastic conditioner application. Orthodontic buccal tubes were then bonded. Shear/peel bond strength was tested with the universal testing machine. The Weibull analysis was performed to indicate the survival probability for each resin composite type. Scanning electron microscope comparison of unetched and etched surface of resin composite was demonstrated. The probabilities of survival at a stress level of 7.8MPa ranked from highest to lowest as follows: hybrid (95.87%), packable (95.38%), flowable (91.81%), compomer (69.95%) and nanofill (36.03%). The survival probabilities of orthodontic buccal tube bonded on hybrid, packable and flowable resin composite were substantially high, while that of nanofill resin composite was remarkably low. From scanning electron microscope, different surface topography of etched surface exhibited unequal resistance to acid etching among different resin composites. Therefore, type of resin composite surface accounted for the differences seen in the survival probabilities of orthodontic buccal tubes.

European Journal of Dentistry, Jan 11, 2022

Objective Different post-sintering processes are expected to be a reason for alteration in the st... more Objective Different post-sintering processes are expected to be a reason for alteration in the strength of zirconia. This study evaluated the effect of post-sintering processes on the flexural strength of different types of monolithic zirconia. Materials and Methods A total of 120 classical-(Cz) and high-translucent (Hz) monolithic zirconia discs (1.2 mm thickness and 14 mm in Ø) were prepared, sintered, and randomly divided into four groups to be surface-treated with (1) as-glazed (AG); (2) finished and polished (FP); (3) finished, polished, and overglazed (FPOG); and (4) finished, polished, and heat-treated (FPHT) technique (n ¼ 15). Biaxial flexural strength (σ) was determined on a piston-on-three ball in a universal testing machine at a speed of 0.5 mm/min. Statistical Analysis Analysis of variance, and post hoc Bonferroni multiple comparisons were determined for significant differences (α ¼ 0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristic strength (σ 0). The microstructures were examined with a scanning electron microscope and X-ray diffraction. Results The mean AE standard deviation value of σ (MPa), m, and σ 0 were 1,626.43

Aaps Pharmscitech, May 17, 2017

Dental caries prevention products available on the market contain only remineralizing agents or a... more Dental caries prevention products available on the market contain only remineralizing agents or antibacterial agents. This study aimed to develop adhesive pastes containing calcium phosphate and α-mangostin for dental caries prevention using the optimization technique. Calcium phosphate was used as a remineralizing agent, and extracted α-mangostin was used as an antibacterial agent. The effect of the independent variables, which were fumed silica, Eudragit ® EPO, polyethylene glycol, and ethyl alcohol, on the responses was investigated. The drying time, erosion rate, calcium release rate, and αmangostin release rate were established as the measured responses. An equation and a model of the relationship were constructed. An optimal formulation was obtained, and its effect on dental caries prevention was investigated using the pH-cycling model. The quadratic equation revealed that the drying time, calcium release rate, and α-mangostin release rate tended to decrease when increasing the fumed silica and decreasing other factors. The erosion rate tended to increase when decreasing Eudragit ® EPO and increasing other factors. The observed responses of the optimal adhesive pastes were not significantly different from the predicted responses. This result demonstrated that optimization is an efficient technique in the formulation development of the adhesive pastes. In addition, the optimal adhesive pastes could enhance acid resistance activity to the tooth enamel.

World Journal of Dentistry, 2017

Aim: This study evaluated the influence of light emitting diode (LED) illumination bleaching tech... more Aim: This study evaluated the influence of light emitting diode (LED) illumination bleaching technique on color stability of various computer-aided design-computer-aided manufacturing (CAD-CAM) of ceramic materials. Materials and methods: A total of 20 disk-shaped samples (width × length × thickness = 10 mm × 15 mm × 2 mm) were prepared from each of the ceramic materials for CAD-CAM including Lava™ Ultimate (L V), Vita Enamic ® (E n), IPS e.max ® CAD (M e), inCoris ® TZI (I C), and Prettau ® zirconia (P r). The samples from each type of ceramic were randomly divided into two groups based upon different bleaching techniques using 35% hydrogen peroxide with and without LED illumination. Colorimetric evaluation was determined using spectrophotometer for color differences. Results: The color difference (ΔE) upon bleaching, either without or with LED illumination [mean ± standard deviation (SD)], for each type of ceramic was 0.34 ± 0.21, 0.54 ± 0.41 for L V groups; 5.59 ± 1.35, 5.81 ± 1.45 for E n groups, 4.60 ± 1.80, 6.92 ± 1.42 for M e groups, 3.43 ± 1.04, 4.14 ± 0.72 for I C groups, and 6.61 ± 0.80, 7.03 ± 0.64 for P r groups respectively. The differences in color changes were indicated upon bleaching procedure in different degrees for the different ceramic materials. The analysis of variance (ANOVA) indicated significant differences of color change due to the effect of bleaching technique on the ceramic material (p < 0.05). Conclusion: Bleaching can affect the color stability of dental ceramics for CAD-CAM. Using 35% hydrogen peroxide bleaching agent with LED illumination caused more color alteration of dental ceramics than without LED illumination. Clinical significance: Bleaching affects color of ceramic materials. Clinicians should be careful in the protection of the existing restoration.

Journal of Esthetic and Restorative Dentistry, Feb 4, 2022

ObjectiveTo evaluate masking ability of different types and thicknesses of ceramics upon various ... more ObjectiveTo evaluate masking ability of different types and thicknesses of ceramics upon various substructures.Materials and MethodsDiscs (Ø 12 mm, thickness 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0 mm) were prepared from Bruxzir‐Anterior® (Bc), Celtra‐DUO® (Cc), and Vita‐Suprinity® (Vc) (n = 15/group). Substructures (2 mm thickness) were prepared from natural dentine (Ds), tetracycline‐stained dentine (Ts), zirconia (Zs), resin composite (Rs), and cast metal (Ms). A spectrophotometer was used to measure the CIE L*a*b* color coordinates of a specimen. Masking ability was determined from the color difference (∆E00) of ceramics between before‐ and after combining with substructure using ANOVA and Bonferroni test (α = 0.05). ∆E00 value was compared with acceptable clinical threshold (∆E00 = 1.8) and an ideal threshold (∆E00 = 0.8).ResultsType‐thickness of ceramics and substructures were significantly affected ∆E00. Ts significantly influenced ∆E00 more than Rs, Ms, Zs, and Ds. No significant ∆E00 upon Ms and Zs was indicated. Bc completely masked Ts and Rs if thickness was ≥0.6 mm, and Zs, Ms, and Ds if ≥0.4 mm. Cc completely masked Ts and Rs if thickness was >1.6 mm, and Zs, Ms, and Ds if >1.4 mm. Vc completely masked Ts if thickness was >1.4 mm, Rs and Ms if >1.2 mm, and Zs and Ds if >1 mm.ConclusionTs is the most influential substructure impact on color appearance, requiring a minimum thickness of 0.6 mm Bc, 1.2 mm Vc, or 1.6 mm Cc to be perfectly masked.Clinical SignificanceMasking ability was significantly influenced by the type and thickness of ceramic material and underlying structure. Monolithic zirconia had a significantly higher masking ability than lithium silicate/phosphate glass ceramic. Ts indicated the most influencial substructure impacting the color appearance of ceramic restoration, which require a minimum thickness of 0.6 mm Bc, 1.2 mm Vc, or 1.6 mm Cc to achieve ideal masking capability.

Journal of Clinical and Experimental Dentistry, 2021

BackgroundSurface treatments are expected to be a reason for alteration in fracture resistance of... more BackgroundSurface treatments are expected to be a reason for alteration in fracture resistance of zirconia. This study evaluated the effect of post-sintering processes on the fracture toughness of different types of monolithic zirconia. Material and MethodsClassical- (Cz) and high-translucent (Hz) monolithic zirconia discs (1.2 mm thickness, 14 mm in Ø) were prepared, and randomly divided for surface treatments with 1) as-glazed (AG); 2) finished and polished (FP); 3) finished, polished, and overglazed (FPOG); and 4) finished, polished, and heat-treated (FPHT) technique (n=15/group). Fracture toughness (KIC) was determined with indentation fracture toughness method at load 1 kg for AG, FPOG and 10 kg for FP, FPHT with 15 sec dwelling time. Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristic toughness (K0). Microstructures were examined with SEM and XRD. ANOVA and multiple comparisons were determined for significant differences (α=0.05). ResultsThe mean±sd value of KIC (MPa.m1/2), m, and K0 were 1.60±0.19, 7.27, 1.71 for CzAG; 9.57±0.89, 9.97, 10.96 for CzFP; 1.61±0.15, 10.56, 1.68 for CzFPOG; 6.45±0.31, 20.31, 6.60 for CzFPHT; 1.45±0.13, 10.91, 1.51 for HzAG; 6.58±0.24, 27.00, 6.70 for HzFP; 1.24±0.05, 23.90, 1.27 for HzFPOG; and 5.07±0.16, 30.51, 5.15 for HzFPHT. The KIC was significantly affected by the post-sintering process, type of zirconia (p<0.05). The Cz indicated a significantly higher KIC than Hz. The FP significantly enhanced KIC, while OG was unable to raise KIC. HT reduced KIC due to reverse phase transformation. ConclusionsPost-sintering processes caused alteration in fracture resistance of zirconia. Fracture toughness was enhanced with FP, but not with either OG or HT process for both Cz and Hz. Surface treatment of zirconia through a finished-polished process is recommended, while glazing and heat-treated are not suggested. Key words:Fracture toughness, glazing, heat treatment, polishing, post-sintering process, zirconia.

International Journal of Dentistry, Mar 20, 2021

Introduction. Nanohydroxyapatite (nano-HA) has been utilized as an alternative agent for dental e... more Introduction. Nanohydroxyapatite (nano-HA) has been utilized as an alternative agent for dental enamel remineralization. is study compared remineralization potential of nano-HA toothpaste (NHT), functionalized tricalcium phosphate toothpaste (TCPT), and fluoride toothpaste (FT) on carious lesions. Materials and Methods. Sixty extracted human premolars were prepared for artificial carious lesions with synthetic polymer gel. Samples were divided into four groups according to testing agents: NHT, TCPT, FT, and one group with no treatment (NT). Each group was subjected to pH-cycling with the application of toothpaste in slurry form twice a day (2-min each) for 10 days. Surface microhardness was measured before demineralization, after demineralization, and after pH-cycling. Hardness at different periods, percentage of hardness recovery (% HR), and percentage of remineralization potential (%RP) were determined and statistically analyzed with ANOVA and Tukey comparisons (α � 0.05). Polarized light microscopy (PLM) was utilized to assess lesion depth. Results. Significant remineralization of carious lesions was observed among different toothpastes compared to NT (p < 0.05). No significant difference in remineralization potential was found among NHT, TCPT, and FT (p > 0.05). No significant difference in % HR and % RP was seen among NHT, TCPT, and FT (p > 0.05). PLM indicated a greater decrease in carious depth upon using NHT compared to TCPT and FT, with minimal increase in depth for NT. Conclusions. NHT has comparable capability to TCPT and FT in hardness recovery. However, decrease in carious depth was evidenced with PLM for NHT more than TCPT and FT. us, NHT was suggested as a potential remineralization product for treating initial carious lesions. Clinical Significance. e study showed that NHT had the potential to remineralize artificial carious lesion. It was confirmed in potential in the lesion depth reduction and forming a new enamel layer. NHT showed its capability as an alternative for dental caries therapeutic.

International Journal of Nanomedicine, May 1, 2018

This study investigates the effects of nano-hydroxyapatite (NHA) gel and Clinpro (CP) on reminera... more This study investigates the effects of nano-hydroxyapatite (NHA) gel and Clinpro (CP) on remineralization potential of enamel and cementum at the cavosurface area of computeraided design and computer-aided manufacturing ceramic restoration. Materials and methods: Thirty extracted human mandibular third molars were sectioned at 1 mm above and below the cemento-enamel junction to remove the cemento-enamel junction portions and replaced them with zirconia ceramic disks by bonding them to the crown and root portions with resin cement. The enamel and cementum with an area of 4×4 mm 2 surrounding the ceramic disk was demineralized with carbopol. The demineralized surfaces were treated with either NHA or CP, while 1 group was left with no treatment. Vickers microhardness of enamel and cementum were determined before demineralization, after demineralization, and after remineralization. Analysis of variance and Tukey multiple comparisons were used to determine statistically significant differences at 95% level of confidence. Scanning electron microscopy and X-ray diffraction were used to evaluate for surface alterations. Results: The mean ± SD of Vickers microhardness for before demineralization, after demineralization, and after remineralization for enamel and cementum were 377.

Journal of Prosthodontics, Jun 16, 2022

European Journal of Dentistry, Jan 11, 2023

Objectives Color stability of provisional restoration is crucial for full mouth reconstruction, w... more Objectives Color stability of provisional restoration is crucial for full mouth reconstruction, which is probably influenced by aging. Therefore, this study evaluated the effect of aging on the color appearance of different provisional materials. Materials and Methods Rectangular specimens (10 Â 10 Â 2 mm) were fabricated from computer-aided design-computer-aided manufacturing (CAD-CAM) (Vita CAD-Temp [VC], TelioCAD [TC], artBloc [RC]), autopolymerized (ProtempIV [PA], Luxatemp [LA], UnifastTrad [UA]), and heat-polymerized polymer (Major C&B [MH]). Each was divided into aging (AG, 5,000 thermocycles of 5°/55°C) and non-aging group (n ¼ 21/group). Color parameters were determined using a spectrophotometer through the CIELAB system. The L Ã , a Ã , and b Ã data were calculated for color appearance (ΔE), translucency parameter (TP), contrast ratio (CR), and opalescence parameter (OP) for each. Statistical Analysis An analysis of variance and multiple comparisons were determined for a significant difference in color appearance alteration of materials upon aging (α ¼ 0.05). Results Statistically significant differences of L Ã , a Ã , b Ã , ΔE, TP, CR, and OP due to the effect of types of material (p < 0.05), aging effect (p < 0.05), and their interactions (p < 0.05) were indicated. Aging affects the color appearance, lightness, chromaticity, translucency, contrast, and opalescence of various types of provisional materials. Color appearance alteration of provisional materials was significantly indicated upon aging (p < 0.05) but within the perceivable limit of clinical acceptance (ΔE diff < 3.0), except for PA and MH. Color stability of CAD-CAM-based poly-methyl methacrylate (PMMA) and autopolymerized PMMA upon aging were better than bis-acryl resin and heatpolymerized PMMA. The TP, CR, and OP alterations of tested materials upon aging were within the perceivable limit. Conclusion Color appearance of provisional restorative materials was influenced by aging. The CAD-CAM-based PMMA and autopolymerized PMMA materials showed better color stability than bis-acryl provisional resin and heat-polymerized PMMA upon aging. Therefore, they were suggested as provisional materials for oral rehabilitation.

Journal of Prosthodontics, Oct 15, 2020

Purpose: Zirconia crowns often crack at the margin. This study determined the loads and the times... more Purpose: Zirconia crowns often crack at the margin. This study determined the loads and the times at which cracks are initiated in high-translucency monolithic zirconia crowns with different margin designs. Materials and methods: A total of 90 crowns were fabricated from Zirconia blanks. The fabricated crowns had different margin thicknesses (light-chamfer, C L and heavychamfer, C H) and collar heights (no-collar, N C ; low-collar, L C ; high-collar, H C). They were grouped as C

International Journal of Dentistry, May 25, 2020

Objective. is study evaluated the effect of ceramic surface treatments on bond strength of metal ... more Objective. is study evaluated the effect of ceramic surface treatments on bond strength of metal brackets to machinable ceramics and veneering porcelain using different adhesive resins. Materials and methods. Machined ceramic specimens (10 × 10 × 2 mm) were prepared from Vitablocs mark II (Vita) and IPS e.max ® CAD (Ivoclar). Layered porcelain fused to metal (IPS d.Sign ® , Ivoclar) was used to fabricate PFM specimens (n � 60/group). Half of specimens were etched (9.6% HF, 15 sec), and the rest were nonetched. ree resin bonding systems were used for attaching metal brackets (Victory series ™ APC II, 3M) to each group (n � 10): Transbond ™ XT (3M), Light Bond ™ (Reliance), or Blugloo ™ (Ormco), all cured with LED curing unit (Bluephase G1600, Vivadent) for 50 s each. Specimens were immersed in deionized water at 37°C for 24 hours prior to shear bond testing (Instron) at crosshead speed of 0.5 mm/min. Debond surface of ceramic and bracket base was examined for failure mode (FM), Ceramic Damage Index (CDI), and Adhesive Remnant Index (ARI). ANOVA and post hoc multiple comparisons were used to analyze the differences in bond strength. e chi-squared test was used to determine significance effect of FM, CDI, and ARI. Results. Significant differences in shear bond strength among group were found (p ≤ 0.05) related to ceramic, surface treatment, and resin cement. Conclusion. Bond strength of bracket to ceramic is affected by type of ceramic, resin cement, and ceramic surface conditioning. Etching ceramic surface enhanced ceramic-bracket bond strength. However, bond strengths in nontreated ceramic surface groups were still higher than bond strength required for bonding in orthodontic treatment.

European Journal of Dentistry

Journal of Dental Sciences

Clinical Oral Investigations

Journal of Prosthodontics

Journal of Clinical and Experimental Dentistry, 2018

The Scientific World Journal, Oct 6, 2021

Journal of Clinical and Experimental Dentistry, 2018

Shear bond strength of ceramic bracket bonded to different surface-treated ceramic e1167

The journal of contemporary dental practice, 2018

Orthodontic Waves, Sep 1, 2008

European Journal of Dentistry, Jan 11, 2022

Aaps Pharmscitech, May 17, 2017

World Journal of Dentistry, 2017

Journal of Esthetic and Restorative Dentistry, Feb 4, 2022

Journal of Clinical and Experimental Dentistry, 2021

International Journal of Dentistry, Mar 20, 2021

International Journal of Nanomedicine, May 1, 2018

Journal of Prosthodontics, Jun 16, 2022

European Journal of Dentistry, Jan 11, 2023

Journal of Prosthodontics, Oct 15, 2020

International Journal of Dentistry, May 25, 2020