Operative dentistry最新文献

Objective: The purpose of this study was to measure clinical competence in preventive and restorative dental procedures among recently graduated dentists entering US military service.

Methods: An anonymous, electronic survey was sent to 201 new dentists and 32 clinical supervisors in the US Air Force, Army, and Navy in 2022. Using a modified Dreyfus model of skill acquisition, new dentists, during their first year following graduation, completed self-assessments of their ability to perform 20 preventive and restorative procedures, and supervisors evaluated the proficiency of the new dentists under their supervision.

Results: A total of 59 (29.3%) new dentists and 25 (78.1%) supervisors responded. The proportion of ratings of competent or higher was calculated, along with a 95% confidence interval, and one-sample chi-square tests were used to compare the proportion against 50%. Supervisor ratings of competent or higher were significantly greater than 50% in caries diagnosis and treatment planning, caries risk assessment, Class III anterior resin composites, and posterior resin composites. Significant discrepancies between new dentist and supervisor ratings occurred with Class I and II amalgam restorations, restoring endodontically treated teeth not requiring a post, and crown preparation and delivery skill levels. When rating new dentists overall, supervisors assessed 71.3% of new dentists at novice or beginner skill level.

Conclusions: Supervisor ratings of new dentists' skill levels were significantly lower than the new dentists' self-assessments for the majority of procedures. Fewer than one-third (28.7%) of new dentists were evaluated as overall competent in preventive and restorative procedures during their first year following graduation.

This study assessed photoactivated dentin-pulp complex materials concerning cell viability, degree of conversion, compressive strength, and bioactive potential. The materials Theracal, Hidrox-cal, and Ultra-Blend underwent cell viability testing using the MTT assay (n = 6), degree of conversion analysis via Raman spectroscopy (n = 5), and compressive strength testing on a universal testing machine (n = 5). Bioactive potential (n = 3) was determined through scanning electron microscopy and Raman spectroscopy after 30 days of immersion in simulated body fluid. For cell viability, the Kruskal-Wallis test was employed, followed by Dunn's post hoc test. Degree of conversion, compressive strength, and bioactivity data were analyzed by one-way ANOVA, followed by Tukey's post hoc tests. For all analyses, α = 0.05 was considered. Cell viability was similar between Hidrox-cal and Ultra-Blend, while Theracal exhibited the lowest cell viability values. The degree of conversion was also higher in the Hidrox-cal group, which did not differ from Ultra-Blend. No differences were observed in compressive strength. The bioactive potential demonstrated a greater formation of crystalline structures in Theracal and Ultra-Blend, however limited. Light-cured pulp capping materials, despite demonstrating good mechanical properties, showed limited performance in terms of bioactivity and cytotoxicity ranging from slight to high.

Objectives: The aims of this study were to investigate (1) whether the addition of catalytic enzymes and violet LED light to the conventional in-office hydrogen peroxide (H2O2) bleaching protocol could improve esthetic results in a shorter time and (2) whether these strategies could minimize adverse effects on the enamel surface and the diffusion of H2O2 through the tooth structure.

Methods: 120 bovine dental discs were divided into two study phases. In phase I, 60 sectioned specimens were pigmented with black tea for analysis of chromatic change, bleaching index, and trans-amelodentinal diffusion. In phase II, 60 unpigmented specimens were evaluated for enamel roughness and microhardness. In both phases, the specimens were divided into four groups (n=15): NC (negative control): no treatment; G45: 35% H2O2 bleaching gel for 45 minutes; GT: 35% H2O2 bleaching gel with peroxidase enzyme for 15 minutes on enamel previously covered with a polycaprolactone nanofiber mesh scaffold; GTL: Same procedure as GT, irradiated with violet LED light for 15 minutes. Esthetic efficacy (ΔE00 and WID) was analyzed in three sessions (T1, T2, T3) and 7 days (T4) after treatment, and H2O2 diffusion was evaluated at T1 (phase I). In phase II, the specimens were evaluated for microhardness and surface roughness at T0 and T4. For the analysis of microhardness, roughness and chromatic alteration, a Two-Factor ANOVA with Repeated Measures was used to evaluate the groups over time, while H2O2 diffusion was analyzed by One-Way ANOVA.

Results: GTL promoted the greatest change in ΔE00 in all sessions; however, ΔWID in GTL did not differ from G45 at T3 and T4. The diffusion of H2O2 in GT was 69% lower than G45. The enamel microhardness and roughness of the GT and NC groups were not altered by treatments, but were significantly worse in G45.

Conclusion: When compared with conventional in-office whitening alone, the strategies tested achieved the same esthetic results in two-thirds less time, reduced alterations to the enamel surface, and reduced the trans-amelodentinal diffusion of H2O2.

Objectives: Various in vitro approaches have been used to evaluate whitening efficacy, utilizing both stained and non-stained tooth substrates, which may influence the outcomes. This study aimed to assess the effect of previous in vitro staining on whitening efficacy and the enamel surface using hydrogen peroxide (HP) gels with different concentrations.

Methods: Bovine enamel/dentin specimens (n=16) were randomly allocated into groups according to the HP concentration [20% (HP20), 30% (HP30), 40% (HP40), and deionized water (negative control)]; and substrate condition (non-stained or stained). Tooth color was measured using a spectrophotometer, and the color difference (ΔE00) and whiteness index (WID and ΔWID) were calculated. Knoop surface microhardness (SMH) and roughness (Ra) of enamel were assessed at different times. Data from both non-stained and stained substrates were analyzed using ANOVA and Tukey post hoc tests (α<0.05).

Results: Significant differences were observed in ΔE00 for different HP concentrations and substrate conditions (p<0.001). Greater tooth color change was found for HP 40, followed by HP30 and HP20. Stained groups exhibited higher ΔE00 values than non-stained ones, except for HP20. Higher values of ΔWID were observed in stained/bleached groups. The staining process reduced SMH and increased Ra.

Conclusions: The bleaching patterns were similar for both non-stained and stained substrates, with higher concentrations of HP bleaching gels resulting in greater tooth color difference. Previous staining increased the variation in whiteness values (ΔWID) following bleaching, but specimens maintained a lower whiteness index after bleaching compared to the non-stained substrate. Staining induced alterations on the enamel surface. These factors indicate that pre-staining of specimens is not essential to evaluate the whitening efficacy of bleaching gels.

Objective: To investigate marginal integrity of experimental and commercial ion-releasing restorative materials before and after thermomechanical loading (TML).

Methods: Standardized mesio-occlusal-distal (MOD) cavities (mesial margins 1 mm below the CEJ, distal margins 1 mm above the CEJ) were restored using six materials, following the manufacturer-recommended adhesive pretreatment, if applicable. One conventional, non-ion-releasing restorative material, Ceram.x Spectra ST (HV) (Dentsply Sirona, Charlotte, NC, USA), and five ion-releasing restorative materials were used (n=8 per group). Four of the ion-releasing materials were commercially available: Cention Forte (Ivoclar Vivadent, Schaan, Liechtenstein), Beautifil II LS (Shofu, Kyoto, Japan), ACTIVA BioACTIVE-RESTORATIVE (Pulpdent, Watertown, MA, USA), and Surefil one (Dentsply Sirona). In addition, an experimental resin composite restorative material with a fluoride-modified bioactive glass was specially produced for use in this study. TML was applied (1.2 M loading cycles, 1.7 Hz, 49 Newtons; 3000 thermal cycles, 5°C-50°C). Restoration margins were assessed before and after TML using scanning electron microscopy (200× magnification) and classified as continuous, noncontinuous, or nonjudgeable. Margin integrity was quantitatively expressed as the percentage of continuous margins in relation to the total measurable margin length. Data were analyzed using Wilcoxon signed-rank and Kruskal-Wallis tests, followed by Dunn post hoc tests and Bonferroni correction and Mann-Whitney U tests (α=0.05).

Results: Each group exhibited significantly reduced marginal integrity after TML. The experimental resin composite showed the significantly highest continuous enamel margins before TML, whereas Surefil one had the lowest (p<0.001). Margin integrity in dentin did not differ significantly among groups (all p=0.236).

Conclusions: The experimental resin composite with a fluoride-modified bioactive glass exhibited marginal integrity similar or superior to a conventional resin composite, while the self-adhesive resin composite Surefil one displayed the lowest marginal adaptation of all groups in enamel.

Objective: This randomized clinical trial aimed to evaluate the efficacy, risk and intensity of tooth sensitivity (TS) and gingival irritation (GI), and esthetic self-perception of in-office dental bleaching using a bleaching gel 1 week after mixing.

Methods and materials: Forty subjects underwent in-office bleaching with 40% hydrogen peroxide (Opalescence Boost PF, Ultradent). In a splitmouth design, each maxillary hemiarch received bleaching gel that was mixed during, or 1 week before, the treatment session. The bleaching procedure was performed in two sessions of 40 minutes with a 7-day interval. Tooth color was assessed before treatment, and 1 week, 2 weeks, and 1 month after the end of bleaching, using a digital spectrophotometer (Vita Easyshade; ΔEab, ΔE00, and ΔWID) and subjective scales (Vita Classical and Vita Bleachedguide; ΔSGU). The risk and intensity of TS and GI were recorded using a Visual Analogue Scale (0-10). Esthetic self-perception was assessed using the Orofacial Esthetic Scale (0-10).

Results: Satisfactory bleaching was achieved in both groups, with no significant differences for objective (ΔEab, ΔE00, and ΔWID; p>0.72) or subjective (ΔSGU [shade guide units], p>0.84) color assessments. No significant differences were found in the risk and intensity of TS (p=0.79; p=0.67) or GI (p=1.0; p=0.85). Patients' esthetic self-perceptions changed after the procedure (p<0.009), mainly on the tooth color question (p<0.001).

Conclusion: In-office dental bleaching with Opalescence Boost PF 40% remained effective, without differences in risk and intensity of TS and GI, even 1 week after mixing.

Rationale: Polishing of resin composites ensures optimal esthetics and longevity. Effective polishing techniques for conventional multi-shade resin composites are well documented. However, less is known regarding acceptable polishing for newer single-shade universal resin composites.

Objective: This study compared the surface roughness of five universal resin composites (Omnichroma, Neo Spectra, Charisma Diamond One, One Shade) and one conventional multi-shade resin composite (Palfique Asteria) following the use of three polishing systems (one-step, Enhance PoGo; two-step, EVE Diacomp Plus Twist; three-step, Sof-Lex) and Mylar strip (without polishing).

Methods: A total of 240 specimens were prepared (n=40 for each resin composite). The specimens were grouped into four subgroups (n=10) based on the polishing system applied. The surface roughness of all specimens was evaluated using a non-contact three-dimensional optical profilometer. One randomly selected specimen from each subgroup underwent scanning electron microscope examination.

Results: Surface roughness was significantly affected by the resin composite type and the polishing system used (p<0.05). The study groups were ranked by surface roughness, from lowest to highest, across all tested materials as follows: Mylar strip < Enhance PoGo < Sof-Lex < EVE Diacomp. The surface roughness values of the universal resin composites were comparable to the multi-shade nanofilled resin composite in all polishing systems.

Objective: This study evaluated the effect of delay of the etch-and-rinse bonding procedure on in vivo real-time intrapulpal temperature during restoration of Class V preparations on human premolars.

Methods and materials: Intact premolars planned for orthodontic extraction from 11 volunteers received infiltrative anesthesia and were isolated using a dental dam. An occlusal preparation was performed using a high-speed diamond bur with air-water spray until obtaining minimal pulp exposure, followed by insertion of a sterile thermocouple probe. A buccal Class V preparation was made using a high-speed diamond bur cooled using air-water spray. To simulate the time spent on caries removal, material placement was delayed 15 minutes until physiologic pulpal temperature (PT) was reestablished (approximately 35°C). Preparations were acid etched and rinsed. A two-step etch-and-rinse bonding agent, Single Bond Universal (Solventum, St. Paul, MN, USA) or Tetric Nano Bond (Ivoclar Vivadent, Schaan, Lichtenstein), was applied and photocured following manufacturers' instructions. The teeth were restored using conventional (Filtek Z250 or Filtek Z350, Solventum) or bulk-fill (Tetric N Ceram Bulk-fill, Ivoclar Vivadent) resin composites, which were photocured with a dual-peak LED light-curing unit (Bluephase 20i, Ivoclar Vivadent). Peak PT and ΔT values were analyzed using two-way repeated measures ANOVA and Bonferroni post hoc tests.

Results: Etch-and-rinse and solvent evaporation procedures reduced PT, despite restoration starting at physiologic PT. Only the 40-second exposure of Filtek Z350 resulted in significantly higher peak PT values compared to baseline (38.2°C ± 2.4°C). ΔT values for Z250 were not significantly different from those for Tetric N-Ceram Bulk-fill.

Conclusion: Even when etch-and-rinse bonding procedures started at physiologic PT, PT decreased, preventing harmful levels of temperature rise in the pulp.

Objective: Although the use of modeling resins for sculpting resin composites is not a recent development, it is still not widely practiced, either because of a lack of knowledge or because of concerns about the potential deleterious effects induced by its use. This study presents a clinical case illustrating how the use of modeling resins, in conjunction with minimally invasive techniques, can achieve satisfactory clinical outcomes in the treatment of deep, unsightly enamel stains.

Methods: A case of severe fluorosis affecting the maxillary anterior segment was treated using a minimally invasive approach. Techniques included microabrasion, macroabrasion, resin infiltration, and resin composite layering with modeling resin. Once discussed, this case will also serve as the basis for a review on the use of modeling resins in restorative dentistry.

Results: This clinical case was successful. The use of modeling resin made it easier to carry out the resin composite layering, thereby helping the clinician to achieve a highly esthetic clinical outcome.

Conclusions: A minimally invasive approach combining microabrasion, macroabrasion, resin infiltration, and resin composite layering can achieve very good esthetic results. Modeling resins appear to be useful in facilitating resin composite placement, although clinical and in vitro studies still seem necessary.