Journal of Esthetic and Restorative Dentistry最新文献

Objective: To conduct a systematic review on the masking ability of subtractively and additively manufactured dental ceramics.

Materials and methods: The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The electronic search was carried out through MEDLINE, Scopus, and Website of Science databases with a date restriction being from 2001 onwards. Publications in English, in vitro studies, and studies regarding the evaluation of the masking ability of crown materials that were subtractively and additively manufactured were included.

Results: Out of 619 eligible articles, 13 were included. A thickness of 1.5 mm for lithium disilicate (LD) resulted in a dramatic decrease in ∆E_ab/∆E₀₀ across all substrates compared to a 1 mm thickness. Low-translucent LD appeared to have the best masking ability regardless of the shade of the try-in paste. Layering flowable composite over the substrates improved masking ability. Darker substrates were the hardest to mask no matter the type of restorative material, try-in paste used, and layering technique. Bilayered restorative materials proved to be superior to monolithic materials regarding masking ability.

Conclusion: Increasing the thickness of subtractively manufactured ceramics materials improves the masking ability. 1.5 mm thickness is found to provide the best masking ability for most ceramic materials. Darker substrates prove to be difficult to mask in comparison to lighter substrates and require either thicker materials and/or more opaque cements. Bilayered crowns are recommended for achieving optimal masking while preserving tooth structure. Despite the increasing demand, there is no study available on 3D-printed (additively manufactured) restoration's masking ability.

Clinical significance: This review provides a comparison of masking abilities of multiple subtractively manufactured ceramic materials and highlight the lack of current knowledge on additively manufactured crown materials. It also emphasizes the importance of having a universal approach to interpreting and communicating color changes between collaborative dental professionals to ensure the same shade predictions. In addition, when masking darker shades, clinicians should be aware that alternative material choice or clinical and technical procedures are essential.

Objective: The purpose of this study was to investigate how cigarette smoking affects the surface roughness (R_a) and stainability of additively and subtractively manufactured resins.

Materials and methods: Two additively manufactured definitive resins (Dentafab, DF and Formlabs, FL) and a subtractively manufactured resin nanoceramic (Cerasmart, CS) were used to fabricate 60 specimens (14 × 12 × 1 mm). After taking baseline R_a and color measurements (ΔE₀₀), they were divided into two groups (n = 10). Using a programmable cigarette smoking simulation device, the study groups smoked 10 cigarettes a day for 30 days. The control groups were kept in artificial saliva for 30 days. The R_a and ΔE₀₀ were performed again. Scanning electron microscope images were taken. Kruskal-Wallis test, Mann-Whitney U, Bonferroni, and Wilcoxon Signed Rank tests were used for statistical analyses (α = 0.05).

Result: Significantly less discoloration was observed in the FL group compared with the other groups (p < 0.001). The R_a of the DF study groups was statistically significantly higher than the control groups (p = 0.005).

Conclusion: All the tested materials had moderately unacceptable color change when previously reported threshold values were considered. There was not found to be any linear correlation between the R_a of materials and smoking-induced discoloration.

Clinical significance: The discoloration and surface roughness of three-dimensional (3D)-produced SLA definitive resin because of smoking are at acceptable levels. Optimized physical and chemical properties of definitive resins are clinically important to extend the life of the restoration. The application of 3D definitive resin can be recommended in clinical practice.

Objective: Chemicals used during canal disinfection and endodontic sealers have a deleterious effect on dentin bond strength. The aim of this study was to evaluate a novel clinical sequence to improve the resin-dentin microtensile bond strength (μTBS) to endodontically treated teeth.

Materials and methods: Twenty human molars were distributed in four experimental groups (n = 5, N = 20): C-control group without exposure to any endodontic chemical substances (2.5% sodium hypochlorite, 17% EDTA and endodontic cement); LDh-late dentin hybridization (Dh) with Dh at the time of final restoration, after exposure to chemical substances; IPDS-immediate pre-endodontic dentin sealing, with Dh before exposure to chemical substances; and PLDh-late Dh after exposure to chemical substances and after dentin repreparation with ultrasonic diamond tip. Teeth were restored with resin composite and the microtensile test was performed after 24 h.

Results: The highest bond strength values were found in the PLDh, IPDS, and C groups, without statistically significant differences among them. The lowest value was found in the LDh group. The LDh group presented a decrease of 70% when compared with the control group.

Conclusion: The resin-dentin microtensile bond strength was significantly improved by dentin hybridization before exposure to chemicals used during endodontics. Otherwise, substantial dentin repreparation is necessary to restore the bond strength after this exposure.

Clinical significance: Early dentin hybridization (IPDS) before endodontic treatment not only improves the microtensile bond strength to dentin but also omitting this procedure would require significant repreparation of the exposed dentin after endodontic treatment to restore the bond strength. Hence, it allows the preservation of healthy tooth structure (no need for repreparation), as well as the reinforcement of weakened cusps and improvement of isolation (if combined with deep margin elevation, when necessary).

Clinical considerations: Conventional facebow records are used to transfer the maxillary cast into the analog articulator. Different reference planes have been described, including the true horizontal or gravity reference plane. A conventional facebow (Kois Dentofacial Analyzer; Panadent) allows the recording of the gravity plane for transferring the maxillary cast into the analog semi-adjustable articulator. Clinical procedures should also allow the maxillary scan transfer into the virtual articulator by using the true horizontal reference plane.

Objective: The present manuscript describes the step-by-step protocol to record the gravity plane and to transfer the maxillary scan into the virtual articulator by using an extraoral scan body system.

Conclusions: The extroral scan body device enables the substitution of the conventional facebow procedure. Additionally, this extraoral scan body is fabricated by using additive manufacturing technologies and eases the complete digital workflow for transferring the maxillary scan into the virtual articulator.

Objective: To investigate how surface treatment affects the color of enamel and dentin, and to evaluate whether the color differences are acceptable.

Materials and methods: Freshly extracted premolars were prepared using diamond burs (blue, red, and yellow tapes). Tooth surfaces were divided into control and acid-etched areas and treated with phosphoric acid (5, 15, 30, 45, and 60 s). Adhesives were applied and light-cured. Hyperspectral images were captured to analyze reflectance spectra, calculating L, a, b, and ΔE2000 values under the D65 illuminant. Enamel and dentin slices underwent atomic force microscopy for surface roughness. A random forest model was trained to assess the effects of multiple factors on color differences. Statistical analyses included one-way ANOVA, Tukey tests, and independent-sample t-test.

Results: Extended acid-etching times notably increased ΔE2000 values for enamel, surpassing acceptable thresholds in all groups except for the 5-s acid-etching followed by adhesive application. Dentin ΔE2000 remained stable regardless of surface treatment. Machine learning highlighted the influence of acid etching and surface roughness on enamel. Bur tape color had minimal impact.

Conclusions: The effects of acid etching on the color vary between enamel and dentin. Greater attention should be focused on enamel surface. Acid-etching time should be appropriately reduced.

Clinical significance: Comprehending the varying impacts of surface treatment on the color of enamel and dentin could contribute to achieving superior esthetic outcomes.

Objective: The aim of the current study was to examine possible associations between gingival thickness and other parameters, such as crown length and width, papilla height and patient's age and gender.

Overview: This cross-sectional study included 238 consecutive white Caucasian consecutive patients in all stages of orthodontic treatment (before, in-course, and after orthodontic treatment). Measurements of gingival thickness were carried out at both central mandibular incisors, mid-facially on the buccal aspect of each tooth, and 2 mm apically to the free gingival margin, with an Ultrasound device. Each patient was scanned with an intraoral 3D scanner before gingival thickness evaluation, where papilla height, and central mandibular and maxillary incisor crown length and width were measured.

Conclusions: Significant (positive) association between gingiva thickness and patient's age and gender were found, with thicker gingiva being observed in older individuals and males. However, no significant association were found between gingival thickness and crown length, crown width, or papilla height.

Clinical significance: Variations in soft and hard tissue architecture significantly impact the long-term aesthetic outcomes of periodontal therapy, prosthetic and implant restorations, and root coverage treatments. Accurately assessing gingival biotype phenotype during treatment planning is critical to prevent complications, particularly in aesthetically sensitive areas.

Objectives: To evaluate the color change and trans-amelodentinal cytotoxicity of a 22% carbamide peroxide (CP) bleaching gel containing different concentration of manganese oxide (MnO₂).

Material and methods: Enamel/dentin discs adapted to artificial pulp chambers were distributed according to treatments: CN-No treatment; CP22%-22%CP; CP22 + 2MnO₂-22%CP + 2 mg/mLMnO₂; CP22% + 6MnO₂-22%CP + 6 mg/mLMnO₂; CP22% + 10MnO₂-22%CP + 10 mg/mLMnO₂ applied for 2 h for 15 days. Color change-CC (ΔE₀₀ and ΔWI_D) (n = 8) was determined at 5, 10, and 15-day periods (ANOVA/Sidak). Trans-amelodentinal cytotoxicity (TC) was assessed after applying the extracts to cultured MDPC-23 cells, which were analyzed concerning their viability (Vi) (n = 8) and oxidative stress (OxS) (n = 8). The amount of hydroxyl radical (OH^•) (n = 4) generated by H₂O₂ degradation (ANOVA/Sidak), and trans-amelodentinal diffusion of H₂O₂ (n = 8) (ANOVA/Tukey) were also evaluated.

Results: CP22 + 10MnO₂ presented higher CC than CP22 for both evaluated equations in all analysis periods (p ≤ 0.04). Among bleached groups, CP22 + 10MnO₂ presented the highest OH^• generation (p ≤ 0.02) and the lowest trans-amelodentinal diffusion of H₂O₂ (p ≤ 0.0004). Therefore, MDPC-23 cells in CP22 + 10MnO₂ exhibited the lowest OxS (p < 0.0001) and consequently the highest Vi (p ≤ 0.0146).

Conclusion: Besides increasing the bleaching efficacy, the strategy of adding 10 mg/mL of MnO₂ to a 22%CP bleaching gel also reduces significantly the trans-amelodentinal diffusion of H₂O₂, diminishing the cytotoxicity caused by at-home bleaching therapy.

Clinical significance: The addition of MnO₂ to a 22% carbamide peroxide bleaching gel improves the color change and reduces the cytotoxicity effects of the product, making at-home bleaching faster and biologically safer.

Objectives: To synthesize experimental toothpastes (ETs) containing four different polymers (sodium linear polyphosphate [LPP]; chitosan [CHI]; sodium hexametaphosphate [HMP]; and sodium pyrophosphate [PP]) and test their ability in preventing and removing tooth extrinsic stain.

Methods: The tooth specimens were randomly assigned into six groups (n = 10): control (artificial saliva), regular toothpaste (RT-no whitening claim), ET 5% LPP, ET 0.5% CHI, ET 5% HMP, and ET 5% PP. Each cycle consisted of chlorhexidine (2 min), staining broth (30 min), artificial saliva (30 min), brushing (45 strokes), and artificial saliva (30 min). Color parameters (L*, a*, and b*) were assessed at baseline and after 21 cycles. ΔE_ab, ΔE₀₀, ΔWI_D, ΔL, Δa, and Δb were analyzed through ANOVA and Tukey test, at a 5% significance level.

Results: ET 5% PP showed lower ΔE_ab and ΔE₀₀ than the control and RT (p < 0.01). For ΔWI_D, PP showed a higher value. For ΔL (p = 0.265) and Δb (p = 0.119), there were no significant differences among the groups. For Δa (p = 0.01), ET 5% PP showed a difference with the control.

Conclusions: The ETs showed a similar effect in preventing and removing tooth extrinsic stains. However, the sodium pyrophosphate-containing toothpaste was the only one with a superior effect in comparison with RT or brushing without toothpaste.

Clinical significance: The use of toothpastes for managing tooth extrinsic stains is a common approach in dentistry. In addition to the abrasives, their effect can be further enhanced by the presence of some polymers. Toothpastes containing sodium pyrophosphate demonstrated a superior ability to control tooth extrinsic stains.

Background: Esthetically pleasing, bright teeth and a symmetrical dental arch are of great importance. There are only a few scientific studies that compare the evaluation of anterior restorations by experts and patients. Additionally, there are hardly any studies that deal with the weighting of esthetic parameters.

Objective: The current study was performed to test the hypothesis that patients and experts evaluate anterior restorations differently and place their emphasis differently. Therefore, aim of this prospective study was to compare the evaluation of the red and white esthetics of anterior restorations by patients and an expert and to find out which parameters play an important role in the evaluation of the esthetic appearance of anterior restorations.

Material and methods: Anterior restorations of 21 patients were analyzed. All patients evaluated their own restorations using a questionnaire of ten defined parameters (pink esthetic score, PES and the white esthetic score, WES). Additionally, the questionnaire was used to determine how important the individual parameters are for them in relation to the assessment of the esthetic result. An expert also gave her assessment and weighting for all 21 patients.

Results: The statistical analysis of the questionnaires shows that the expert assigned lower values, particularly in the evaluation of the PES. The expert weighted individual parameters of the PES to be more important than the patients. The type of abutment of the restoration (tooth or implant) had no influence on the evaluation of the restorations.

Discussion/conclusion: The study shows that patients and experts have different assessments of the esthetics and the weighting of the various parameters. Nevertheless, patients are sensitive to esthetic deviations and patient preferences should be taken into account in anterior restorations.

Statement of problem: Esthetic dental features, especially the maxillary anterior teeth, significantly influence perceived attractiveness. Gingival recessions can negatively affect smile esthetics, particularly when asymmetrical.

Purpose: This study aimed to investigate the perception of dentists and non-professionals regarding subtle variations in the apically displaced soft tissue surrounding a lateral or central incisor.

Materials and methods: Based on an ideal image of the esthetic zone, asymmetrical modifications of either a central or lateral incisor in the maxillary anterior were created and used in a digital survey asking participants to assess the overall appearance of the smile, using a visual analog scale (VAS). The dental expertise, age, and gender of the participants were recorded. For each image, the question was posed to identify if any of the teeth caused a visible irritation. The mean results of each tooth alteration and the correlation between dental expertise were statistically analyzed.

Results: A total of 114 participants were polled. There was a significant difference in the esthetic perception between the central and lateral incisors (p < 0.001). The perception threshold for a noticeable asymmetrical recession was 1.2 mm for the central and 2.0 mm for the lateral incisor. Gender and age showed no significant difference in the esthetic evaluation, and dental expertise was only significantly different for larger recessions (p < 0.05).

Conclusion: The asymmetric changes were more noticeable for the central incisor than the lateral incisor. A unilateral recession change of 0.8 mm did not appear to influence the assessment of the overall smile. The dental expertise, age, or gender of the participants did not significantly correlate with a stricter esthetic perception.

Clinical implications: The present study highlights that the perception of unilateral recession changes in the anterior maxilla varies between central and lateral incisors, with lateral incisor recessions being less impactful on the overall appearance of the smile. These findings suggest that small gingival changes can be acceptable for the overall esthetic outcome, underscoring the importance of discussing patient expectations and treatment options before restoration or orthodontic treatment and prioritizing the gingival margin of the central incisor which appeared more noticeable.