Operative Dentistry[JOURNAL]
Sun
200 papers
Effect of Battery Level During Successive Charging Cycles on the Performance of Certified and Low-cost Uncertified Light-curing Units Available on E-commerce.
Peres TS, Oliveira G, da Silva Sakamoto SP … +3 more , da Silva Faria M, Carlo HL, Soares CJ
Oper Dent · 2024 Nov · PMID 39407435 · Publisher ↗
OBJECTIVE: To evaluate the influence of battery level on power (mW), emission spectrum (mW/cm2/ nm), and light distribution on the active tip (mW/ cm2) of certified (FDA/ANVISA) and low-cost uncertified light-curing unit...
OBJECTIVE: To evaluate the influence of battery level on power (mW), emission spectrum (mW/cm2/ nm), and light distribution on the active tip (mW/ cm2) of certified (FDA/ANVISA) and low-cost uncertified light-curing units (LCUs) purchased through e-commerce. METHODS: Seven LCUs, three certified: VALO Grand (Ultradent); Radii Xpert (SDI); and LED.B (Woodpecker); and four uncertified: 1 Sec; BS 300; LED curing light; and VAFU (VRN, AZDENT), were used. The LCUs were evaluated by calculating the power (mW) after each sequential five exposure cycles of 20 seconds and the emission spectrum (mW/cm2/nm) in the initial and final cycles, using an integrating sphere during three battery charging cycles. Beam profiling was used to check the light distribution on the LCU tip after every 50 exposure cycles until the battery fully discharged. Data were analyzed by linear regression between power and the number of exposure times (R2). RESULTS: The certified LCUs VALO Grand (R2=0.005), LED.B (R2=0.02), and Radii Xpert (R2=0.09) and the uncertified LCU VAFU (R2=0.002) had no significant power reduction during the three battery charging cycles. The uncertified LCUs BS 300 (R2=0.87), 1 Sec (R2=0.60), and LED curing light (R2=0.83) showed significant power reduction, decreasing the emission spectrum (mW/cm2/nm) at the end of the battery charging cycle. The light distribution on the active tip across the level battery was modified significantly with successive exposure times. CONCLUSIONS: The certified LCUs (VALO Grand, Radii Xpert, and LED.B) and uncertified LCU (VAFU), maintained power, emission spectrum, and light distributions during the tested battery life cycles. Low-cost certified LCU LED.B exhibited inhomogeneous light concentrated at the center of the tip. Low-cost uncertified LCUs-BS 300, 1 Sec, and LED curing light-had significant power reductions during the battery cycles and increased inhomogeneous light distribution along the successive exposure times.
Bonding and Cleaning Effects of Irrigation Protocols Using Calcium Hypochlorite on the Post-space Radicular Dentin.
Besegato JF, Bravo GR, Zaniboni JF … +5 more , Belizário LG, de Almeida E, Gelio MB, Escalante-Otárola WG, Kuga MC
Oper Dent · 2024 Nov · PMID 39407433 · Publisher ↗
This study evaluated the effect of 2.5% sodium hypochlorite (SH) or calcium hypochlorite (CH) submitted to passive ultrasonic irrigation (PUI) or conventional irrigation (CI) on the incidence of residues and the bond str...
This study evaluated the effect of 2.5% sodium hypochlorite (SH) or calcium hypochlorite (CH) submitted to passive ultrasonic irrigation (PUI) or conventional irrigation (CI) on the incidence of residues and the bond strength of the cementation system to post-space dentin. Distilled water (DW) and 2.5% SH followed by 17% EDTA (SH-ED) were used as negative and positive control groups, respectively. The cervical, middle, and apical thirds of the post space were evaluated. One hundred and twenty bovine incisors were endodontically treated and post-space preparation was performed. The specimens were randomly assigned to six groups, according to the solution and irrigation method: DW-CI, SH-ED-CI-SH, SH-CI, SH-PUI, CH-CI, and CH-PUI. The incidence of residues (n=10) over the dentin was evaluated by scores using SEM images. Other specimens were irrigated as previously described and the post cementation was immediately performed using a conventional dual resin cement and a two-step etch-and-rinse adhesive system. Push-out and failure modes were performed for bonding evaluation. Kruskal-Wallis and Dunn test for incidence of residues data and one-way ANOVA and Tukey tests for bond strength data were used at a significance level of 5%. The protocols that showed a lower incidence of residues were: SH-ED-CI-SH, SH-PUI, and CH-PUI for the cervical third and SH-ED-CI-SH for the middle third (p<0.05). In the apical third, the protocols were similar to each other (p>0.05). Bond strength values were higher after irrigation with DW-CI for all thirds (p<0.05). 2.5% sodium or calcium hypochlorite negatively impacted the adhesion interface and exhibited a greater incidence of residues over the post-space radicular dentin.
Enhancing Light-curing Competence: A Study of Radiant Exposure and Training Outcomes Among Dental Students.
Imbery TA, Allen AE, Larkin B … +2 more , Romani I, Carrico C
Oper Dent · 2024 Nov · PMID 39407430 · Publisher ↗
OBJECTIVES: The aim of this study was to measure radiant exposure and time necessary to deliver 16 J/cm2 of radiant exposure to simulated Class I and Class III preparations by first-year dental students. First-year denta...
OBJECTIVES: The aim of this study was to measure radiant exposure and time necessary to deliver 16 J/cm2 of radiant exposure to simulated Class I and Class III preparations by first-year dental students. First-year dental students (n=89) received a 60-minute lecture on light-curing. Using the Managing Accurate Resin Curing Patient Simulator (MARC-PS) and protective blue-light-blocking glasses, students twice light-cured Class I and Class III restorations, using the Valo Grand Cordless light-curing unit with infection-control barriers on both Standard and High Power Plus modes. After their first attempts, if students did not obtain at least 16 J/cm2 of radiant exposure (RE), they received additional instruction. Paired t-tests were used to determine the change between the first and second attempts. After averaging two attempts, radiant exposure and time were compared between Standard and High Power Plus modes within individuals using paired t-tests. RESULTS: 79% of students provided 16 J/cm2 of radiant exposure on both attempts for Standard and High Power Plus modes. High Power Plus mode provided statistically significantly more radiant exposure and required less time to obtain 16 J/cm2 of radiant exposure for both restorations. CONCLUSIONS: The MARC-PS is useful to identify students requiring instruction. It may be prudent to use High Power Plus mode or increase time on Standard mode to light-cure Class I restorations.
Effect of Surface Treatments on Shear-bond Strength of Glass Ionomer Cements to Silver Diamine Fluoride-treated Simulated Carious Dentin.
Koh WT, Yeoh OT, Yahya NA … +1 more , Yap AU
Oper Dent · 2024 Nov · PMID 39407428 · Publisher ↗
OBJECTIVES: This study investigated the effect of different surface treatments on the shear bond strength (SBS) and failure modes of self-cured (SC) and light-cured (LC) high-viscosity glass ionomer cements (HVGICs) to s...
OBJECTIVES: This study investigated the effect of different surface treatments on the shear bond strength (SBS) and failure modes of self-cured (SC) and light-cured (LC) high-viscosity glass ionomer cements (HVGICs) to silver diamine fluoride (SDF)-treated simulated carious dentin (SCD). METHODS AND MATERIALS: Extracted human premolars were sectioned and pH cycled for 10 days to simulate carious dentin. The demineralized specimens were treated with 38% SDF (Riva Star) for 2 minutes, washed, stored in deionized distilled water at 37°C for 2 weeks, and subjected to the following surface treatments (n=14): T1 - no treatment (control); T2 - 10 seconds polyacrylic acid (PAA); T3 - 5 seconds phosphoric acid (PPA); T4 - 5 seconds PPA plus universal adhesive (Zipbond); and T5 - 5 seconds PPA plus resin-modified GIC adhesive (Riva bond LC). SC (Riva Self-cure HV) and LC (Riva Light-cure HV) HVGICs were applied to the conditioned specimens and stored in artificial saliva at 37°C for 1 week. SBS and failure modes were subsequently determined. Statistical analyses were performed using Kruskal-Wallis/post-hoc Mann-Whitney U and Chi-square tests (α=0.05). RESULTS: The highest SBS was observed when SC and LC were restored with T2 and T5, respectively. Significant differences in SBS were as follows: SC - T2, T1 > T5, T3; LC - T5, T4, T3 > T2. SC generally exhibited adhesive failures, while LC presented both adhesive and mixed failures. CONCLUSION: The preferred method for preparing SDF-treated carious dentin before restoration application is PAA for SC and PPA plus RMGIC adhesive for LC HVGICs.
Effect of an Additional Hydrophobic Adhesive Layer Application on the Clinical Performance of Class V Resin Composite Restorations: An 18-month Randomized Clinical Trial.
Berkman M, Tuncer S, Karabay F … +3 more , Demirci M, Tekçe N, Baydemir C
Oper Dent · 2024 Nov · PMID 39407427 · Publisher ↗
OBJECTIVES: This study aimed to evaluate the 18-month clinical performance of two different one-step adhesives that were applied alone or with an additional hydrophobic adhesive layer to noncarious cervical lesions. METH...
OBJECTIVES: This study aimed to evaluate the 18-month clinical performance of two different one-step adhesives that were applied alone or with an additional hydrophobic adhesive layer to noncarious cervical lesions. METHODS AND MATERIALS: One hundred sixty teeth in 31 patients were included in the study. Each patient received at least four restorations. A 2-hydroxyethylmethacrylate (HEMA)-containing one-step self-etch adhesive (Clearfil S3 Bond Plus, Kuraray Noritake, Noritake, Japan) and a HEMA-free universal adhesive (G-Premio Bond) were applied to noncarious cervical lesions with or without additional hydrophobic adhesive (Heliobond) randomly. Teeth were restored with a nanohybrid composite. Restorations were evaluated according to FDI criteria at baseline, 6-, 12-, and 18-month recalls. Data were analyzed with the Kruskal-Wallis and the Friedman analysis of variance (ANOVA) tests (α=0.05). RESULTS: At 18 months, recall rates were 100%, and there was no significant difference between four different adhesive applications in terms of any criteria (p>0.05). The cumulative retention rates were 92.5%, 92.5%, 97.5%, and 100% for the restorations with one-step self-etch, one-step self-etch plus hydrophobic adhesive layer, a universal adhesive, and a universal adhesive plus hydrophobic adhesive layer, respectively. CONCLUSION: An additional hydrophobic adhesive layer was found to have no significant effect on the 18-month clinical performance of two different one-step adhesive systems with and without HEMA.
Optimal Hydrofluoric Acid Etching Duration and Impact of Silane/Adhesive on Profilometric Properties and Bonding to Lithium Disilicate Glass Ceramics.
Porto TS, Faddoul AJ, Park SJ … +3 more , Feitosa VP, Eyüboğlu TF, Ozcan M
Oper Dent · 2024 Sep · PMID 39300738 · Publisher ↗
OBJECTIVES: This study aimed to assess the surface roughness, surface free energy (SFE), and shear bond strength (SBS) on a lithium disilicate glass-ceramic surface following varying etching protocols (time variation) an...
OBJECTIVES: This study aimed to assess the surface roughness, surface free energy (SFE), and shear bond strength (SBS) on a lithium disilicate glass-ceramic surface following varying etching protocols (time variation) and application of silane either with or without adhesive material. METHODS AND MATERIALS: Lithium disilicate glassceramic (LDGC) computer-aided design and computer-aided manufacture (CAD/CAM) blocks were cut using a slow-speed cutting mechanism. CAD/CAM blocks were then evaluated for surface roughness, 6 groups (n=20); SFE,12 groups (n=5); and SBS, 10 groups (n=10). The cut CAD/CAM blocks were randomly allocated to 28 groups. Groups were based on the following: 30 or 90 seconds of etching with 9% hydrofluoric acid (HF); application or absence of silane coupling agent (Sil); and application or absence of adhesive (Adh).The control group (Cont) had untreated surfaces. Unetched surfaces were surveyed with only silane (Sil), only adhesive (Adh), or silane+adhesive (SilAdh). Further etched groups were HF30 with HF for 30 seconds, HF30-Sil, HF30-Adh, and HF30-SilAdh. Alternative 90-second etching times produced similar groups: HF90, HF90-Sil, HF90-Adh, and HF90-SilAdh. A digital profilometer was used to assess the surface roughness of specimens, and two readings were recorded. Sessile drop analysis was used to examine SFE specimens, and the OWRK model was modified to measure liquid surface tension. A universal testing machine (UltraTester, Ultradent Products, Inc, South Jordan, UT, USA) was utilized for the SBS test, with the crosshead speed set at 0.5 mm/min until failure. Representative treated specimens from each group were submitted to surface morphological evaluation and chemical analysis using scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDXS) (n=3). After data collection, evaluation using one- or two-way analysis of variance and the post-hoc Tukey test (α=5%) was conducted. RESULTS: A longer etching time of 90 seconds produced a rougher surface. After the 90-second etching process, SFE displayed the greatest values; nevertheless, the use of silane did not affect SFE. For every group examined, the application of silane followed by adhesive resulted in an increase in SBS and more stable bonding over time. SEM/EDXS showed that etching times did affect the amount of cerium on the surface and altered surface morphology. CONCLUSIONS: Higher and more consistent bond strengths have been observed with longer etching periods. Silane and adhesive application on the ceramic surface showed stronger and enhanced bond strength, specifically when longer etching times were employed.
Accuracy of Color Determination by Intraoral Scanners in Bleached and Unbleached Teeth: A Clinical Study.
Kaya BD, Atali PY, Kahramanoĝlu E … +1 more , Tarçin B
Oper Dent · 2024 Sep · PMID 39300737 · Publisher ↗
PURPOSE: This clinical study aimed to evaluate the color measurement ability of intraoral scanners (Trios 3, (3Shape, Copenhagen, Denmark) and Cerec Omnicam, (Dentsply Sirona, Charlotte, NC, USA) in comparison to VITA Cl...
PURPOSE: This clinical study aimed to evaluate the color measurement ability of intraoral scanners (Trios 3, (3Shape, Copenhagen, Denmark) and Cerec Omnicam, (Dentsply Sirona, Charlotte, NC, USA) in comparison to VITA Classical and VITA 3D-Master shades obtained by a spectrophotometer (Easyshade V, VITA, Zahnfabrik, Bad Säckingen, Germany). METHODS: Four hundred eighty teeth from thirty patients were included in the study. Fifteen patients had never undergone bleaching, and the other fifteen had undergone professional bleaching within the last 6 months. VITA Classical and VITA 3D Master shades were determined using Trios 3 (T3), Cerec Omnicam (CO), and EasyShade V from cervical, middle, and incisal/occlusal areas of maxillary and mandibular central and lateral incisors, canines, and first premolars. Color accuracy rates (cAR) were assessed by categorizing the color data according to the Munsell color system for bleached and unbleached teeth, maxillary and mandibular, and teeth arranged from anterior to posterior in each quadrant. McNemar, Mann-Whitney U, and Wilcoxon tests and Point Biserial Correlation Analysis were used for statistical analysis (significance level α=0.050). RESULTS: The bleached teeth had a significantly higher cAR for T3 in VITA 3D Master and VITA Classical guides (p<0.05). The cAR of the incisal area in VITA 3D Master was significantly lower in both scanners (p<0.05) except for the lightness/hue/chroma of bleached teeth. T3 cAR increased statistically significantly from anterior to posterior (p<0.001); however, no significant difference was found for CO (p=0.482). CONCLUSION: The color accuracy rates of both scanners for shade guides that included all color components in this study were below 30%, which was not clinically satisfactory for color measurement. Confirming the measurements with a spectrophotometer is recommended.
Effects of UV Postcuring Times on the Color Stability, Surface Properties and Conversion of 3D-printed Temporary Resin Composites.
de Sousa LC, Pereira A, Curinga M … +4 more , de Souza B, Batista A, Borges B, Carreiro A
Oper Dent · 2024 Sep · PMID 39187962 · Publisher ↗
OBJECTIVE: To evaluate the effects of UV postcuring times on color stability (CS), surface properties (wettability [°] and surface roughness [Ra]), and conversion of 3D-printed resins for temporary restorations. METHODS:...
OBJECTIVE: To evaluate the effects of UV postcuring times on color stability (CS), surface properties (wettability [°] and surface roughness [Ra]), and conversion of 3D-printed resins for temporary restorations. METHODS: Disc-shaped specimens (10.0×3.0 mm) and maxillary central incisors (8.2×10.3 mm) were fabricated using provisional 3D-printed resin (PriZma Bio Prov [PZ] and PrintaX AA TEMP [PX]) in A2 shade and subjected to UV postcure times of 0 (T0), 5 (T1), 10 (T2), and 15 (T3) minutes (n=15). The incisors were used for CS evaluation with a colorimeter. In contrast, discs were used to measure the contact angle using the sessile drop method, surface roughness with an optical profilometer, and degree of conversion with FT-NIR. For CS, Ra, contact angle, and degree of conversion, a two-way ANOVA with Bonferroni post-hoc test (α=0.05) was used. RESULTS: PX resin demonstrated greater color stability than PZ (p=0.001). Long UV postcuring times (10 to 15 minutes) will increase the contact angle (p=0.013) and stabilize the degree of conversion (p=0.01), while 5 to 10 minutes of UV postcuring will provide better surface smoothness (p=0.04) of both resins. CONCLUSIONS: Long UV postcuring times (10 to 15 minutes) lead to greater alterations in color, contact angle, and stability of the degree of conversion, while 5 to 10 minutes lead to a smoother surface of the 3D-printed temporary resins.
Effectiveness of Three Bleaching Techniques for Endodontically Treated Teeth: A Randomized Clinical Trial.
Gaidarji B, Perez BG, Durand LB
Oper Dent · 2024 Sep · PMID 39187959 · Publisher ↗
BACKGROUND: Various techniques, products, and protocols are used for the bleaching of non-vital teeth. The walking bleach technique involves sealing the bleaching agent in the pulp chamber. In the inside/outside techniqu...
BACKGROUND: Various techniques, products, and protocols are used for the bleaching of non-vital teeth. The walking bleach technique involves sealing the bleaching agent in the pulp chamber. In the inside/outside technique, a low-concentration bleaching agent is applied at home using a custom tray. In the in-office technique, a high-concentration bleaching agent is applied by a dental professional. Limited research has compared the effectiveness of these techniques. OBJECTIVE: This clinical trial aimed to evaluate the effectiveness of the walking bleach, the inside/outside, and the in-office bleaching techniques. METHODS AND MATERIALS: Fifty-four discolored teeth were selected according to eligibility criteria, randomized, and assigned to three treatment groups (n=18): walking bleach (sodium perborate - SP), inside/outside bleaching (7.5% hydrogen peroxide -HP7.5), and in-office bleaching (35% hydrogen peroxide - HP35). A cervical seal was placed in all the teeth, and nonvital bleaching was performed according to each technique. The CIELab color coordinates were measured using a clinical spectrophotometer at baseline, weekly, and at the 1-week follow-up. ΔE00 and ΔWID were calculated between the baseline and each evaluation time point. The ANOVA, Fisher exact, and Kruskal-Wallis tests were used to compare the quantitative variables, and the Fisher exact test, to determine the association among categorical variables. Bleaching effectiveness was interpreted by 50:50% perceptibility and acceptability thresholds. RESULTS: As the treatment progressed, all techniques presented a significant increase in L* and WID (p<0.001), and a significant decrease in a* and b* (p<0.001). HP7.5 and HP35 presented greater increases in WID mean values, in comparison with SP (p=0.006). No significant differences were observed among the techniques for ΔE00 after treatment completion (p=0.383). There were no statistical differences in bleaching effectiveness among the techniques after treatment completion (p=0.098). CONCLUSION: All techniques presented excellent effectiveness after treatment completion. However, HP7.5 and HP35 techniques provided a more rapid whitening response.
Effect of Successive At-home Bleaching Sessions on the Surface Properties, Biaxial Flexural Strength, and Reliability of CAD-CAM Monolithic Materials.
Queiroz J, Amaro LF, Massucatto LO … +3 more , Dovigo LN, Adabo GL, Fonseca RG
Oper Dent · 2024 Sep · PMID 39187958 · Publisher ↗
Although at-home bleaching can recover the optical properties of stained CAD-CAM monolithic materials, little is known about its impact on their surface and mechanical properties, especially when successive sessions are...
Although at-home bleaching can recover the optical properties of stained CAD-CAM monolithic materials, little is known about its impact on their surface and mechanical properties, especially when successive sessions are performed. This study evaluated the effect of successive at-home bleaching sessions on the microhardness, roughness, topography, biaxial flexural strength (BFS), and reliability of CAD-CAM monolithic materials. Disks from Lava Ultimate (LU), Vita Enamic (VE), and IPS Empress CAD (EMP) were fabricated and submitted to up to three bleaching sessions. At-home bleaching was performed with 10% carbamide peroxide, and each session consisted of one application for 10 hours/day for 14 days. The analyses of the aforementioned parameters were assessed before and after the first, second, and third bleaching sessions, except for BFS, which was evaluated at baseline and after the third session. The Weibull modulus was calculated from the BFS data. The microhardness of the three materials as well as the roughness of LU were not affected by the sessions, whereas the roughness of VE and EMP increased from the second session. All materials displayed topographic changes, which became more pronounced with the increase in the number of sessions. Although bleaching decreased the BFS of the materials, it did not adversely affect their reliability. Successive at-home bleaching sessions with the protocol used in the present study cannot be considered a safe procedure for the materials evaluated.
Combined Minimally Invasive Esthetic Rehabilitation of Dental Fluorosis-5-year Follow-up: Case Report.
Dokumacigil G, Korkut B, Atali PY
Oper Dent · 2024 Sep · PMID 39187955 · Publisher ↗
Dental fluorosis (DF) is a specific esthetic issue characterized by a persistent condition in which there is a disruption in enamel development, leading to the formation of hypomineralized enamel. The resulting unusual a...
Dental fluorosis (DF) is a specific esthetic issue characterized by a persistent condition in which there is a disruption in enamel development, leading to the formation of hypomineralized enamel. The resulting unusual appearance varies in intensity, presenting as mildly white and opaque to dark brown, and significantly impacts individuals' esthetic features and self-confidence. The objective of this case report was to assess the efficacy of microabrasion, dental whitening, and resin infiltration in terms of resolving lesions, tracking the sensitivity of teeth, and evaluating patient satisfaction over a period of time. A minimally invasive treatment approach in a 27-year-old woman with severe DF is detailed. The treatment plan involved enamel microabrasion, in-office bleaching, and two weeks of at-home bleaching, followed by resin infiltration for the affected tooth under rubber dam isolation. After a 5-year follow-up, the assessment of the patient's esthetic appearance indicated a successful treatment of teeth affected by DF.
Influence of Surface Pretreatment on the Bond Strength of a Resin Luting Cement to Saliva-contaminated Enamel and Dentin.
Iwama H, Ishii R, Takamizawa T … +5 more , Aoki R, Watanabe S, Hayashi K, Kamimoto A, Miyazaki M
Oper Dent · 2024 Sep · PMID 39187948 · Publisher ↗
OBJECTIVES: This study aimed to evaluate the influence of surface pretreatment on the shear bond strength (SBS) of a resin luting cement to enamel and dentin with saliva contamination. The surface free energies (SFE) of...
OBJECTIVES: This study aimed to evaluate the influence of surface pretreatment on the shear bond strength (SBS) of a resin luting cement to enamel and dentin with saliva contamination. The surface free energies (SFE) of the adherent surfaces were also determined. METHODS AND MATERIALS: Bovine enamel and dentin were used in this study. For the saliva-contamination, human saliva was applied to the adherent surface for 60 seconds and then air-dried, and the specimens without saliva contamination served as controls. One group of contaminated surfaces was untreated (SC), and the others were pretreated with Katana Cleaner (KC), Multi Etchant (ME), or Ultra-Etch (UE). Fifteen specimens were prepared to measure the SBS for each test group.The mixed resin luting cement paste was applied to the alumina-blasted surface of a stainless-steel rod and placed on the prepared tooth surface. The luting cement was light irradiated for 40 seconds. The bonded specimens were stored for 24 hours at 37°C and half of the bonded specimens underwent 10,000 thermal cycles. The SBS and SFE of the specimens after different pre-treatments were measured. RESULTS: The two-way ANOVA revealed that the factors of pretreatment agent and storage condition had a significant effect on the SBS to enamel and dentin. The SFE values of the SC group were significantly lower than those of the other groups in both enamel and dentin. The SFE of pretreated surface was material dependent. CONCLUSIONS: A pretreatment agent containing functional monomers was shown to be effective in removing saliva contaminants and in creating an effective bonding surface for the resin luting cement.
Effect of Bleaching Treatments on the Mechanical Properties of the Dentin Matrix and on Collagen Biodegradation by Endogenous Protease.
Junquera LB, Carlos NR, Otsuki M … +1 more , Basting RT
Oper Dent · 2024 Sep · PMID 39169512 · Publisher ↗
This study evaluated the mechanical properties of demineralized dentin matrix submitted to different bleaching treatments, as well as the changes in mass and collagen biodegradation brought about by endogenous protease....
This study evaluated the mechanical properties of demineralized dentin matrix submitted to different bleaching treatments, as well as the changes in mass and collagen biodegradation brought about by endogenous protease. Dentin collagen matrices were prepared to receive the following treatments (n=12): no bleaching treatment (C-control), 10% carbamide peroxide (CP-Opalescence PF, Ultradent, South Jordan, UT, USA) 10%/8 hours/ day/14 days, and 40% hydrogen peroxide (HP-Opalescence Boost, Ultradent), 40 minutes per session/3 sessions. The dentin matrices were evaluated for elastic modulus and mass before and after treatments and ultimate tensile strength after treatments. The solution collected during storage was evaluated for hydroxyproline release. There was no statistically significant difference between CP and C in terms of the elastic modulus (p=0.3697) or mass variation (p=0.1333). Dentin beams treated with HP and C presented significant mass loss after the first session (p=0.0003). HP treatment led to complete degradation of collagen matrices after the second bleaching session. After the second session, CP showed higher hydroxyproline concentration than C (p<0.0001). Ultimate tensile strength was lower for CP than C (p=0.0097). CP did not affect the elastic modulus or the dentin collagen matrix mass but did promote hydroxyproline release by endogenous protease and reduce the ultimate tensile strength. HP significantly affected the mechanical properties of dentin and promoted complete degradation of the demineralized dentin collagen matrix.
Effect of Surface Treatment with Zirconium Dioxide Slurry on the Bond Strength of Resin Cement to Ultratranslucent Zirconia.
Colombino A, Bellan MC, Correr-Sobrinho L … +5 more , Miranzi B, Calabrez-Filho S, Platt JA, Spohr AM, Borges GA
Oper Dent · 2024 Sep · PMID 39169511 · Publisher ↗
This laboratory study aimed to evaluate the effects of zirconium dioxide (ZrO2) slurry surface treatment on the bond strength of ultratranslucent zirconia to resin cement using different ceramic primers. The surface morp...
This laboratory study aimed to evaluate the effects of zirconium dioxide (ZrO2) slurry surface treatment on the bond strength of ultratranslucent zirconia to resin cement using different ceramic primers. The surface morphology was evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the interface was evaluated by SEM. Additionally, the phase composition was analyzed by X-ray diffraction (XRD). Specimens of zirconia (n=120) were obtained and divided into two groups according to the surface treatment: (1) airborne particle abrasion with 50-μm aluminum oxide (n=60) and (2) ZrO2 slurry (n=60). The 60 specimens were then further divided into three groups (n=20) according to the ceramic primer application: no primer (NP), Monobond N (MB), and Clearfil ceramic primer (CP). Four resin cement cylinders were built on each ceramic specimen. Half of the specimens (n=10) were subjected to a microshear bond strength (μSBS) test after 24 hours of storage in distilled water, and the other half (n=10) were subjected to a μSBS test after thermocycling. Additional specimens were prepared for SEM, AFM, and XRD analyses. According to the Kruskal-Wallis and Student-Newman-Keuls post hoc tests, the μSBS values were significantly higher for MB and CP than for NP (p<0.05), and there were no significant differences in μSBS for both surface treatments associated with MB and CP after 24 hours of storage (p>0.05). Thermocycling significantly decreased the μSBS values for all specimens, especially for the NP groups and ZrO2 slurry treatment groups, and gaps at the interface were observed by SEM. SEM and AFM analyses showed agglomerate-type irregularities on the ceramic surface for ZrO2 slurry treatment. XRD spectra showed that ZrO2 slurry did not cause phase transformation. It was concluded that ZrO2 slurry promoted irregularities on the ultratranslucent zirconia surface, not causing phase transformation; moreover, the values of μSBS were comparable to those of airborne particle abrasion with aluminum oxide. However, neither surface treatment nor ceramic primer prevented the degradation of the interface.
Effect of Radiotherapy on the Adhesive Interface of Caries-affected Dentin and Bioactive Restorations: A Micro-CT Analysis.
Köse LK, Oglakci B, Özduman ZC … +3 more , Akdur K, Mayadağlı A, Arhun N
Oper Dent · 2024 Sep · PMID 39169509 · Publisher ↗
PURPOSE: This study aimed to analyze the presence of defects within the adhesive interface formed with five bioactive dental materials and caries-affected dentin concerning the timing of radiotherapy (before or after the...
PURPOSE: This study aimed to analyze the presence of defects within the adhesive interface formed with five bioactive dental materials and caries-affected dentin concerning the timing of radiotherapy (before or after the restorative procedures) by micro-CT. METHODS AND MATERIALS: A total of 96 carious human molars were randomly allocated into the following groups based on the timing of the radiotherapy sequence: radiotherapy followed by restoration (RT1) or restoration followed by radiotherapy (RT2). Then, six subgroups were established within these groups based on the type of materials used (n=8). Following cavity preparation and caries removal, a universal adhesive (G-Premio Bond) was administered in self-etch mode or accompanied by applying suitable cavity conditioners according to the manufacturers' guidelines. Subsequently, restorations were performed using five bioactive restorative materials (resin-modified glass-ionomer [Fuji II LC], high-viscosity glass-ionomer hybrid [EQUIA Forte HT], giomer [Beautifil II], alkasite [Cention N], and dual-cure bulk-fill composite [Activa Bioactive Restorative]) and a conventional microhybrid resin composite (Filtek Z250). The radiotherapy regimen encompassed 60 Grays (Gy) administered at a rate of 2 Gy/day over 6 weeks, 5 days a week. Micro-CT analysis was employed to assess adhesive defects at the interface between caries-affected dentin and the restorations. The data were analyzed using Kruskal-Wallis, Mann-Whitney U, and Dunn tests (α=0.05). RESULTS: RT2 caused significantly higher adhesive defects than RT1 for the Filtek Z250 and Activa Bioactive Restorative subgroups (p<0.05). For RT1, no significant differences were found in adhesive defects among all tested subgroups (p>0.05). By contrast, for RT2, adhesive defects were significantly higher for the Activa Bioactive Restorative and Cention N subgroups than for the EQUIA Forte HT and Beautifil II subgroups (p<0.05). CONCLUSIONS: When using most bioactive restorative materials, the timing of radiotherapy had no significant influence on the adhesive interface. Regarding restoration following a radiotherapy protocol, a favorable impact was identified with high-viscosity glass ionomer hybrid cement and giomer bioactive restorations compared with dual-cure bioactive bulk-fill composite and alkasite restorations.
Flexural Properties, Wear Resistance, and Microstructural Analysis of Highly Filled Flowable Resin Composites.
Francois P, Attal JP, Fasham T … +6 more , Troizier-Cheyne M, Gouze H, Abdel-Gawad S, Le Goff S, Dursun E, Ceinos R
Oper Dent · 2024 Sep · PMID 39169507 · Publisher ↗
OBJECTIVE: This study aimed to evaluate the flexural properties and two-body wear resistance of nine highly filled flowable resin composites relative to those of viscous and conventional low-filled flowable composites. I...
OBJECTIVE: This study aimed to evaluate the flexural properties and two-body wear resistance of nine highly filled flowable resin composites relative to those of viscous and conventional low-filled flowable composites. In addition, scanning electron microscopy (SEM) analysis of the microstructures was performed. METHODS AND MATERIALS: For each resin composite group (n=12), 12 specimen bars (25 mm × 2 mm × 2 mm) were fabricated using a silicon mold for performing flexural strength (FS), flexural modulus (E), flexural toughness (FT), Weibull modulus (m) tests, and SEM microstructural analysis. For each group, ten bars were tested using a three-point flexural test on a universal testing machine, while the other two were embedded in acrylic resin before being observed by SEM for structural analysis. During the two-body wear test with a chewing simulator, 8 specimens (12 groups, n=8) of each resin composite group were manufactured in a specific mold and subjected to 120,000 cycles of wear against a steatite ball, and the depth loss was measured. Three one-way ANOVA tests followed by Tukey's post hoc tests were conducted to compare the flexural and wear properties among the different groups. RESULTS: The majority of highly filled composites tested in this study exhibited similar flexural strengths (between 105.68 MPa and 135.49 MPa) and superior wear resistance to those of viscous composites. The flexural moduli (between 5.12 GPa and 9.62 GPa) of these composites were in between those of the viscous and low-filled composites tested in this study. CONCLUSIONS: The highly filled flowable composites tested in this study exhibited different in vitro properties but were often superior to those of viscous resin composite suggesting their possible use for posterior restorations.
Influence of Battery Levels in Cordless LED Light-curing Units on Properties of Resin Cement and Glass Fiber Post Retention.
Segatto TD, Dolenkei KK, Bernardes P … +3 more , Soares CJ, Pacheco RR, Raposo LH
Oper Dent · 2024 Sep · PMID 39135205 · Publisher ↗
PURPOSE: This study aimed to assess the impact of battery levels in single-peak and multi-peak light-curing units (LCUs) on irradiance, and their effects on glass fiber post push-out bond strength to root dentin and the...
PURPOSE: This study aimed to assess the impact of battery levels in single-peak and multi-peak light-curing units (LCUs) on irradiance, and their effects on glass fiber post push-out bond strength to root dentin and the degree of conversion of dual-cure universal resin cement. METHODS AND MATERIALS: Sixty bovine roots underwent endodontic treatment and were randomly distributed into 6 groups (n=10), formed by combining two LCUs (single-peak and multipeak) and three battery levels (100%, 50%, and 10%). A spectrophotometer measured irradiance (mW/ cm2) and spectral irradiance (mW/cm2/nm). Push-out bond strength (PBS) tests occurred at three root regions (cervical, middle, and apical), with optical and scanning electron microscopy for failure mode analysis. Degree of conversion (DC) was evaluated across the root regions. Data were analyzed using two-way repeated measures ANOVA and the Tukey HSD test. The Fisher exact test verified failure modes (α=0.05). RESULTS: As multipeak LCU battery levels decreased, emitted irradiance also diminished, with notable PBS reductions in the apical thirds. Failure modes were influenced by different conditions, primarily exhibiting mixed modes. Battery levels significantly impacted DC in the multipeak LCU, particularly in the cervical region, while the single-peak LCU exhibited DC reduction at the 10% battery level in the cervical region. CONCLUSIONS: Emitted irradiance, resin cement DC, and glass fiber post bond strength to root dentin may be influenced by varying cordless LCUs and battery levels.
Instrumental and Visual Evaluation of the Chameleon Effect of Single-shaded Composite Resins.
Adiguzel RM, Kose LK, Arhun N
Oper Dent · 2024 Jul · PMID 38987939 · Publisher ↗
OBJECTIVE: To evaluate the shade-matching ability of single-shade resin-based composite restorations in different thicknesses using both instrumental and visual techniques. METHODS AND MATERIALS: Cavities with 4 mm diame...
OBJECTIVE: To evaluate the shade-matching ability of single-shade resin-based composite restorations in different thicknesses using both instrumental and visual techniques. METHODS AND MATERIALS: Cavities with 4 mm diameter and 2 mm (n=96) or 3 mm (n=96) depth were prepared in acrylic incisor teeth of shades A2, A3, B3, and C2 and restored with three single-shade resin composites, Omnichroma (Tokuyama Dental America, Encinitas, CA, USA [OM]), Vittra APS Unique (FGM Dental Group, Joinville, SC, Brazil [VU]), Zenchroma (President Dental, Allershausen, Germany [ZC]), and a microhybrid resin composite (Filtek 3M Z250 3M ESPE, St Paul, MN, USA [FZ]) of A2, A3, B3, and C2 shades. Readings were obtained using VITA Easyshade V spectrophotometer for the teeth and restorations. The CIEDE2000 (ΔE00) color difference formula was used, and the values were assessed using three-way analysis of variance (ANOVA). Forty-eight evaluators graded the shade match of 32 different specimens visually as (A) best shade match, (B) intermediate shade match, and (C) poor shade match. RESULTS: FZ material achieved satisfactory matches for both thicknesses, across all shades, and OM material demonstrated statistically significant lower shade matches than the ZC and the FZ materials (p<0.05). VU exhibited poor shade match with the highest ΔE00 value on C2 shade. According to the visual examination, the best shade matches were observed for FZ on A3-shade and ZC on C2-shade teeth. CONCLUSIONS: Shade matching for 2 mm and 3 mm-thick composite resin restorations is material- and tooth-shade dependent.
Theobromine for Remineralization of White Spot Lesions on Dental Enamel: A Systematic Review and Meta-analysis.
Silva AD, Gonçalves RDS, Catão MV
Oper Dent · 2024 Jul · PMID 38987932 · Publisher ↗
AIM: This systematic review and meta-analysis evaluated theobromine's (Theobroma cacao) potential in remineralizing white spot lesions in dental enamel. Methods: This study is reported according to the PRISMA checklist a...
AIM: This systematic review and meta-analysis evaluated theobromine's (Theobroma cacao) potential in remineralizing white spot lesions in dental enamel. Methods: This study is reported according to the PRISMA checklist and was registered in PROSPERO (CRD42023414371). In vitro tests that evaluated the remineralizing potential of theobromine compared to fluoride ion after demineralization for the formation of white spot lesions on enamel were selected, with no limitation on the year of publication. Electronic searches were performed in PubMed/MEDLINE, Scopus, and Web of Science by two independent researchers. Thirty articles were received of which six were selected according to the inclusion criteria. RESULTS: The selected studies evaluated the Enamel Surface Microhardness (SMH), Vickers or Knoop, before and after treatment with theobromine and fluoride solutions. For the SMH Vickers, there were no differences between groups at baseline (p=1.00; mean difference: -0.00; CI: -11.36 to 11.36) and after treatment (p=0.51; mean difference: 4.12; CI: -8.16 to 16.41). The results of SMH Knoop showed differences between groups at baseline, favoring the experimental group (p=0.002; mean difference: 9.84; CI: 3.65 to 16.02) and after treatment favoring the control group (p=0.00001; mean difference: -5.45; CI: -7.62 to -3.27). CONCLUSION: The use of theobromine increases the microhardness of dental enamel subjected to a demineralization process, thus being effective in the remineralization of this tissue with success equivalent to that obtained with the use of fluoride.
Inorganic Phosphate Effect in a Hydrogen Peroxide-based Bleaching Agent: Physicochemical, Mechanical, and Morphological Properties of Dental Enamel.
Garcia KG, Nunes GP, Delbem A … +5 more , Dos Santos PH, Fernandes G, Robles HF, Lemos P, Danelon M
Oper Dent · 2024 Jul · PMID 38987929 · Publisher ↗
OBJECTIVES: This in vitro study aimed to assess the impact of incorporating calcium glycerophosphate (CaGP) and sodium fluoride (NaF) in addition to 35% hydrogen peroxide concerning the enamel mechanical and morphologica...
OBJECTIVES: This in vitro study aimed to assess the impact of incorporating calcium glycerophosphate (CaGP) and sodium fluoride (NaF) in addition to 35% hydrogen peroxide concerning the enamel mechanical and morphological properties. METHODS: Specimens of bovine enamel were chosen based on their initial surface hardness (SHi) and subsequently divided into five gel groups (n=12): 1) 35% Hydrogen Peroxide (HP) Gel; 2) HP + 0.1% NaF Gel (HP/NaF); 3) HP + 0.25% CaGP Gel (HP/CaGP); 4) HP + 0.1% NaF + 0.25% CaGP Gel (HP/NaF/CaGP) and 5) HP Blue 35% Gel (HP Blue). The bleaching gels were applied thrice, for 40 min, at intervals of 7 days each. After 21 days, the final surface hardness (SHf), integrated hardness (IH), Polydispersity Index (PdI) and Zeta Potential (Zp), surface roughness (Ra, after and before), and surface/structural analysis by Scanning Electron Microscopy (SEM) were determined. The data were submitted to ANOVA (one-way and two-way) followed by the Student-Newman-Keuls test (α=0.05). RESULTS: The addition of NaF to HP reduced demineralization by 11.5% in relation to HP (p<0.05). The NaF/CaGP association reduction is 22.8 and 20% higher in comparison to HP/NaF/CaGP and HP Blue, respectively. The IH when the PH/NaF/CaGP bleaching gel was applied, was 14% higher compared to HP and HP Blue groups. CONCLUSIONS: It can be concluded that the association of NaF and CaGP with the 35% hydrogen peroxide gel (HP/NaF/CaGP) significantly changed tooth enamel demineralization in terms of surface, depth, roughness, and enamel morphology.
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