Baseline Specimens of Erosion and Abrasion Studies

Retrospective Study on Orthodontic Gingival Recession Correction Using Clear Aligners

Background and Objectives: Our study aims to evaluate the effectiveness of ClearCorrect® clear aligners (The Straumann Group) in improving gingival recession, which developed following prior fixed orthodontic treatment. The specific objectives were to assess changes in recession severity in patients with orthodontic gingival recessions following aligner therapy and to determine whether the initial severity of recession influenced improvement rates across three categories-mild (RT1), moderate (RT2), and severe (RT3)-as defined by the Cairo classification. Materials and Methods: Fifty-six patients with gingival recession from previous orthodontic treatment received aligner therapy for seven to twelve months, focusing on 146 recession sites, primarily in the lower anterior region. Recession severity was classified and tracked as RT1, RT2, and RT3. Statistical analyses, including a Chi-square test, assessed improvement rates across these categories. Results: Among severe recessions (RT3), 52% showed no improvement, while 48% exhibited some improvement, with 16% improving to RT1. In the moderate group (RT2), 63% improved to RT1, and 16% resolved. The mild group (RT1) showed a 58% reduction in recession depth. Chi-square testing confirmed a statistically significant difference in improvement rates across the three groups (p = 1.44 × 10-7). Conclusions: Clear aligners may contribute to gingival recession improvement, particularly in mild and moderate cases (RT1 and RT2), though severe cases (RT3) show a more limited response.

Whitening Efficacy of Toothpastes on Coffee-Stained Teeth: An Enamel Surface Analysis

AIM

This study aimed to identify the optimal toothpaste for removing coffee-induced stains while also evaluating its impact on tooth enamel through roughness and abraded depth parameters, providing a comprehensive understanding of their effects.

MATERIALS AND METHODS

Three whitening toothpastes and 2 conventional toothpastes were prepared for a simulated brushing procedure on coffee-stained bovine enamel tooth specimens. Using a toothbrushing machine, up to 10,000 brushstrokes were completed, while spectrophotometric readings were taken at designated intervals. A mixed-effects model for statistical analysis determined the effects of toothpaste and brushing on colour change, roughness, and abraded depth.

RESULTS

Whitening toothpastes significantly deviated from the control (P < .001, P < .001, and P < .003, respectively), whereas the conventional toothpaste did not exhibit a significant contrast (P < .081). Regarding colour restoration following coffee staining, whitening toothpastes showed higher restoration than conventional toothpastes. Surface roughness and abraded depth parameters increased with accumulated brushing.

CONCLUSIONS

Sodium hexametaphosphate-containing toothpaste demonstrated the highest efficacy in removing coffee-induced stains and restoring tooth colour. Nevertheless, this stronger whitening effect was associated with increased abrasion. While conventional toothpastes exhibited some whitening effects, the most substantial improvement in lightness was consistently observed with whitening toothpastes.

CLINICAL RELEVANCE

Understanding how whitening toothpaste affects enamel integrity is crucial for refining formulations and advancing dental care. This knowledge lays the groundwork for more effective oral care products and improved whitening procedures, ultimately enhancing the overall quality of dental treatments.

The bleaching effect of office bleaching agents containing S-PRG filler evaluated by pH value and electron spin resonance

OBJECTIVES

Surface reaction-type pre-reacted glass-ionomer (S-PRG) filler releases six types of ions with a neutralizing ability. This study evaluated the effect of S-PRG filler incorporation in an H₂O₂-based bleaching material on the bleaching efficacy, pH, and reaction state.

MATERIALS AND METHODS

The experimental bleaching material was formulated by the addition of 5% or 10% S-PRG fillers to the powder part. The stained bovine teeth were treated with the prepared bleaching paste. Commission internationale de l'éclairage (CIE) L*a*b* color space values were recorded before and after bleaching, and the color difference (ΔE) and whiteness index (WI_D) were calculated. Moreover, the used bleaching formulations were assessed for their pH values and reaction state by evaluating the oxidation state of manganese (Mn⁺²) using electron spin resonance (ESR).

RESULTS

The results of ΔE and WI_D showed that the addition of S-PRG filler increased the bleaching effect, but there was no significant difference between the groups with 5% and 10% S-PRG filler. A significant increase in pH in S-PRG filler groups (5% pH 6.7, 10% pH 6.8) was found compared to the 0% group (pH 4.8). ESR measurements showed that the signal emitted from Mn⁺² decreased over time. The S-PRG filler groups showed a significantly higher reduction in Mn⁺² compared to the 0% group, with no significant difference between the 5% and 10% S-PRG groups.

CONCLUSIONS

S-PRG filler addition resulted in improved bleaching efficacy, higher reaction rate, and pH values that are close to neutral.

CLINICAL RELEVANCE

S-PRG filler addition may be effective on the bleaching outcome of H₂O₂-based materials.

Remineralization of early enamel lesions with a novel prepared tricalcium silicate paste

To evaluate the remineralization potential of prepared tricalcium silicate (TCS) paste compared to silver diamine fluoride-potassium iodide (SDF-KI) and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on artificial enamel lesions. Thirty permanent sound molars were collected for the study. After cleaning, root cutting, and applying acid-resistant nail varnish, leaving a 4 × 4 mm buccal window, the teeth were subjected to demineralization process. The teeth were divided into three treatment groups (n = 10). In each group, the teeth were sectioned buccolingually to obtain two halves (30 self-control and 30 experimental halves). The self-control halves were subjected to cross-sectional microhardness (CSMH), energy-dispersive X-ray spectroscopy at 50, 100, and 150 µm from the external enamel surface, and micromorphological analysis at the superficial enamel surface. The experimental halves were subjected to the same tests after 30 days of remineralization. Three-way analysis of variance (ANOVA) outcomes showed no significant difference in CSMH after treatment among the three different groups at the different levels (p > 0.05). Meanwhile, three-way ANOVA outcomes showed a significant difference in calcium/ phosphate ratio after treatment among the three different groups at the different levels. (p < 0.05). The tricalcium silicate paste used in this study showed potential remineralization in subsurface enamel lesions.

The Use of Bulk Fill Resin-Based Composite in the Sealing of Cavity with Margins in Radicular Cementum

The aim of this systematic review was to evaluate if the newly introduced bulk fill resin-based composite provides a better marginal sealing in cavity preparations with margins in dental cementum. The population investigation comparison outcome (PICO) framework was: in cavity preparation with margins in dental cementum of human extracted teeth, do bulk fill resin base composites provide a better marginal sealing than non-bulk fill resin-based composites? We performed our research on April 21, 2020. Two authors independently evaluated the abstract and titles for eligibility criteria. Two authors independently extracted the data and assessed the risk of bias in single studies. After the initial screening of 400 abstract and titles, the full text of the articles, that could meet the eligibility criteria, were obtained via the university library. A total of 36 full-text articles were evaluated; 11 articles were finally eligible for the review. Eight studies showed statistically differences, but not significant, in the marginal sealing between bulk fill and nonbulk fill resin-based composite (p > 0.05). One study showed statistically significant differences: SonicFill and Grandio showed better marginal sealing than GrandioSo and SDR(r) (Sirona Dentsply, New York, United States) and the latter two showed better marginal sealing than Filtek Supreme (p < 0.05). One study showed statistically significant less marginal gap of SDR than Filtek Bulk Fill (p = 0.0015) and Filtek Supreme (p < 0.0001). One study showed SDR to have a significantly higher microleakage than the other materials tested (p < 0.05). Based on our current literature review, there are not enough data to establish if bulk fill resin base composite provides a better or a worse marginal sealing at cementum margins.

Systematic Review on White Spot Lesions Treatments

The difference in refractive index between the healthy enamel and the demineralized area generates a lesion with a milky white opaque appearance, clearly distinguishable from the surrounding healthy enamel. The aim of this systematic review was to evaluate if the infiltration technique is the most efficient treatment to resolve a white spot lesion when compared with remineralization and microabrasion techniques. The Population/Intervention/Comparison/Outcome question investigated: “in enamel WS lesion, the infiltration treatment compared to remineralization or microabrasion treatments is more or less effective in the camouflage effect?.” The research was performed on electronic databases, including Ovid MEDLINE, PubMed, and web of science. The search was conducted up to April 1, 2020. The scientific search engines produced 324 results. Only 14 were screened after screening. Based on the articles analyzed in this systematic review, the resin infiltration technique seems to be the most effective and predictable treatment for the aesthetic resolution of WSLs.