Effect of incorporation of calcium polyphosphate sub-microparticles in low-concentration bleaching gels on physical properties of dental enamel.

AIM: To evaluate the bleaching efficacy and effects on enamel properties of experimental gels with carbamide peroxide (CP; 10%) or hydrogen peroxide (HP; 6%) containing calcium polyphosphate sub-microparticles (CaPPs). METHODS: A total of 216 bovine tooth specimens were divided for microhardness and color analyses (n = 108) and block randomized into nine groups (n = 12): (G1) commercial CP (Whiteness Perfect, FGM; Brazil); (G2) experimental CP; (G3) CP-0.5%CaPPs; (G4) CP-1.5%CaPPs; (G5) commercial HP (Potenza Bianco, PHS; Brazil); (G6) experimental HP; (G7) HP-0.5%CaPPs; (G8) HP-1.5%CaPPs; (G9) artificial saliva. The gels' pH values were determined with a bench pH meter. Color (ΔE, ΔE00, ΔWID) and microhardness variation were evaluated before and after the therapy. Part of the specimens used for microhardness was submitted to the scanning electron microscopy (SEM) (n = 3) and energy-dispersive X-ray spectroscopy EDX (n = 3) analyses. Statistical analyses were performed in the R statistical software (α = 0.05). Linear mixed models for repeated measures in time were used to analyze microhardness and L* values. Generalized linear models were used to analyze the a*, b*, ΔE, ΔE00, and ΔWID, considering a group effect. The EDX data were analyzed using a one-way ANOVA with Tukey's test. RESULTS: The gels' pH remained over 6,0. All gels effectively bleached the specimens and did not differ significantly. When compared to the control group, the hardness was significantly lower in the G1, G2, G6, and G7 groups. The G3, G4, G5, and G8 groups did not differ significantly (p > 0.05). CONCLUSION: The incorporation of CaPPs in low-concentration whitening gels reduces its negative effects on microhardness without interfering with their bleaching efficacy.

Maintenance of enamel properties after bleaching with high-concentrated hydrogen-peroxide gel containing calcium polyphosphate sub-microparticles.

OBJECTIVE: To assessed the physical and chemical properties of human-enamel after treatment with an experimental bleaching gel containing 35%-hydrogen peroxide (HP) and calcium polyphosphate sub-microparticles (CaPP). MATERIALS AND METHODS: Enamel/dentin specimens (4 × 4 × 3 mm) were obtained (n = 120) and allocated to different groups: control (saliva only); experimental (HP35%); commercial (whiteness-HP-Maxx); CaPP0.5% (HP35% + CaPP0.5wt%); CaPP1.5% (HP35% + CaPP1.5wt%). Three sessions were performed. The specimens' color was assessed using a spectrophotometer and the color (ΔE/ΔE00) and bleaching index (ΔWID) determined. The surface roughness and microhardness were assessed with a roughness tester and Knoop indenter. Raman spectroscopy was performed to obtain the ratios between the areas under the 431, 580, and 1070 cm-1 and the 960 cm-1 bands (430:960, 580:960, 1070:960). Kruskal-Wallis and Dunn compared the color, Ra, and SMH data. The Raman data was analyzed with Kruskal-Wallis and Dunn (α = 5%). RESULTS: The ΔE, ΔE00, and ΔWID were similar among the bleached groups (p > 0.05). The roughness was not different between the groups (p > 0.05). After the 3rd session, CaPP0.5% had higher microhardness than the experimental (p < 0.05). The 1070:960 was higher in the experimental than in the CaPP1.5% and control (p < 0.05). CONCLUSIONS: In human enamel, CaPP did not alter the bleaching effectiveness or roughness, and additionally, CaPP-containing gels increased the microhardness and preserved the mineral content when compared to the experimental without CaPP. CLINICAL RELEVANCE: Experimental bleaching gels containing calcium polyphosphate sub-microparticles as a mineral source reduce the mineral content alteration and superficial microhardness reduction, known potential side effects of the in-office bleaching treatments.

Altered physical-chemical properties of home bleaching gels after an accelerated stability study and their effects on tooth enamel.

OBJECTIVES: To investigate the physical-chemical properties of home bleaching gels based on Carbamide Peroxide (CP) and Hydrogen Peroxide (HP) after accelerated stability (AS) and its effects on enamel. MATERIALS AND METHODS: A total of 360 bovine teeth blocks were divided (n = 12): Control, CP10%-Whiteness Perfect, CP10%-Pola Night, HP7.5%-Pola Day, and HP7.5%-White Class Calcium. Microhardness (KHN), roughness (Ra), color (ΔE and ΔE00), hardness, compressibility, elasticity, cohesiveness, adhesiveness, weight, pH, and calcium (Ca) quantification in enamel were analyzed without storage of the bleaching gels and after AS at 1 and 3 months. Data of Ca, KHN, and Ra were analyzed through mixed models for repeated measurements and the Tukey-Kramer test. Values of weight, hardness, compressibility, and elasticity were analyzed with two-way ANOVA and Tukey's test. ΔE/ΔE00 data, cohesiveness, and adhesiveness were analyzed with Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: Groups subject to AS had lower ΔE and ΔE00 compared to those without storage. Lower KHN and higher Ra values were found after bleaching treatment in all groups compared to controls. Higher amounts of Ca were found on the first day of evaluation in the gels subject to AS for 3 months, regardless of the bleaching agent used. CONCLUSIONS: Incorrectly stored bleaching gel accentuates adverse effects on enamel. Temperature and humidity interfere directly with the chemical stability of bleaching agents, reducing their properties. CLINICAL RELEVANCE: HP is an unstable oxidizing agent when stored at high temperatures. Therefore, pH becomes more acidic and potentiates the demineralizing effect on enamel.

Nano-hydroxyapatite-induced remineralization of artificial white spot lesions after bleaching treatment with 10% carbamide peroxide.

OBJECTIVE: To assessed in vitro the effect of nanohydroxyapatite (n-HA) to improve the aesthetic appearance and microhardness of white spot lesions (WSL) when associated with a low-concentration bleaching agent (carbamide peroxide-CP10%). MATERIAL AND METHODS: Enamel/dentin specimens (n = 60) of 5 × 5 × 2.2 mm were prepared, of these, 48 were submitted to pH-cycling to create artificial WSL. Subsequently, these were allocated into five groups (n = 12): n-HA; n-HA + CP10%; CP10%; WSL control (WSLC ); sound control (Sound). The color was assessed at baseline, pre-treatment, and post-treatment using a spectrophotometer, and the color (ΔE/ΔE00 ) and whiteness index (ΔWID) alterations were determined. The enamel cross-sectional microhardness (CSMH) was evaluated (post-treatment) with a Knoop indenter, 25gf/5 s, 20-200 µm. The data was analyzed through generalized linear models (α = 5%). RESULTS: ΔE and ΔE00 were significantly higher for the bleached groups (n-HA + CP10% and CP10%), and the n-HA was higher than the WSLC group (p < 0.05). ΔWID was significantly higher for the bleached groups (p < 0.05). The CSMH values were significantly higher in the sound group than in the n-HA, CP10%, and WSLC groups (p < 0.05). The WSLC had lower microhardness than the n-HA + CP10% and sound groups (p < 0.05). CONCLUSION: n-HA is suitable to remineralize and recover the color of the WSL. However, its association with CP10% maintains the esthetical outcome while increasing its in-depth remineralizing effect. CLINICAL SIGNIFICANCE: Considering the aesthetic and functional repercussions of the WSL persistence, treatments that tend to improve its physical appearance and reinforce its weakened substructure in a non-invasive way are ideal. For this associating low-concentration, bleaching agents to the remineralizing treatments is promising to treat this type of lesions.

COMPLIANCE OF RANDOMIZED CLINICAL TRIALS ON DENTAL CARIES PREVENTION METHODS WITH THE CONSORT STATEMENT: A SYSTEMATIC REVIEW.

OBJECTIVE: Reporting of randomized controlled trials (RCTs) in dentistry remains suboptimal. Considering the positive impact of the Consolidated Standards of Reporting Trials (CONSORT) guidelines on the quality of evidence in RCTs, the main objective of this systematic review was to determine whether RCTs on dental caries prevention conform to these guidelines. The secondary objective was to assess the association between CONSORT adherence and the year and impact factor of the journal in which the study was published. METHODS: A systematic search was conducted in different databases using appropriate terms to retrieve RCTs that assessed the caries-preventive effect of at least 2 of the following materials-fluoride varnish, resin-based fissure sealants, and ionomer-based fissure sealants-on the occlusal surfaces of permanent molars. Since the first CONSORT statement was published in 1996, a time frame from 1997 to 2020 was established for the identification of studies. Selected articles were assessed according to their adherence to the CONSORT statement, risk of bias (Cochrane risk of bias tool, RoB 2.0), and journal impact factor based on the InCites Journal Citation Reports. The year of publication and other relevant data were also recorded. SPSS (SPSS Statistics 25.0, IBM©) was used to perform the linear correlation analyses to determine the relationship between the article CONSORT score (previously determined) and the year of publication and journal impact factor. A significance level of 5% was established for all analyses. RESULTS: Of 3196 references retrieved, 30 articles were selected and evaluated. Using RoB 2.0, 8 studies were classified as having a high risk of bias, 16 as having some concerns about the risk of bias assessment, and 6 as having a low risk of bias. Concerning CONSORT adherence, 77% of the studies adequately reported the intervention domain, since the methodology for the application of fluoride varnish or sealant materials was thoroughly described. However, the participants' setting and location, random sequence generation, randomization, and the flowchart description of the losses/exclusions domains were poorly reported. Meanwhile, the allocation concealment process was not reported in 83% of the articles. Correlation analyses indicated a positive relationship between CONSORT adherence and the year of publication, as well as the journal impact factor. CONCLUSION: When assessing clinical trials on the prevention of occlusal caries, most RCTs examined followed the CONSORT statement. However, some methodological domains remain poorly reported, demonstrating the need to improve CONSORT compliance in these RCTs.

Enzymatically Driven Mineralization of a Calcium-Polyphosphate Bleaching Gel.

To examined alkaline phosphatase enzyme (ALP) activity and the effects of incorporating it in the thickener solution of a hydrogen-peroxide-based bleaching gel containing calcium-polyphosphate (CaPP) on the orthophosphate (PO43-) levels, bleaching effectiveness, and enamel microhardness. ALP activity was assessed at different pH levels and H2O2 concentrations, and in H2O- and Tris-based thickeners. Circular dichroism (CD) was used to examine the ALP secondary structure in water-, Tris-, or H2O2-based mediums. The PO43- levels were evaluated in thickeners with and without ALP. Enamel/dentin specimens were allocated into the following groups: control (without bleaching); commercial (Whiteness-HP-Maxx); Exp-H (H2O-based); CaPP-H; ALP-H (CaPP+ALP); Exp-T (Tris-based); CaPP-T; and ALP-T (CaPP+ALP). Color changes (ΔE/ΔE00) and the bleaching index (ΔWID) were calculated, and surface (SMH) and cross-sectional microhardness (CSMH) were assessed. The two-way ANOVA and Tukey's post-hoc tests were used to compare ALP and PO43- levels; generalized linear models were used to examine: ΔE/ΔE00/SMH/CSMH; and Kruskal-Wallis and Dunn's tests were used for ΔWID (α = 5%). The ALP activity was higher at pH 9, lower in H2O2-based mediums, and similar in both thickeners. The CD-spectra indicated denaturation of the enzyme upon contact with H2O2. The PO43- levels were higher after incorporating ALP, and the ΔE/ΔE00/ΔWID were comparable among bleached groups. SMH was lower after bleaching in Exp-H, while CSMH was highest in ALP-T.

Impact of Finishing Protocols on Color Stability of CAD/CAM Ceramics: A Systematic Review.

PURPOSE: To analyze the current evidence on the impact of surface finishing protocols (such as manual polishing or glazing) on the color stability of in vitro simulated pigmentation of CAD/CAM ceramics. MATERIALS AND METHODS: Five electronic databases were searched on February 12, 2020. In vitro experimental studies were included based on the following strategy: intervention = surface treatment of CAD/CAM ceramics with glazing agents; comparison = surface treatment of CAD/CAM ceramics with manual polishing; and outcomes = color stability. Two reviewers independently assessed the risk of bias. RESULTS: Among 1,390 articles that were screened, 6 in vitro studies were considered for qualitative analysis. Five articles confirmed changes in the color of ceramics when they were immersed in pigmented solutions. One article investigated the color stability of the samples via ultraviolet (UV) aging. Among the 6 studies analyzed, 4 showed clinically acceptable color alteration values represented by ΔE irrespective of the finishing protocol applied (glazing or mechanical polishing). Two articles presented clinically unsatisfactory color variation (ΔE > 3.3 and ΔE > 2.7) following mechanical polishing of a zirconia-reinforced lithium silicate ceramic. Coffee and red wine proved to be the beverages with the greatest potential for ceramic pigmentation. Only 1 article had a high risk of bias. CONCLUSION: For clinicians, most of the studies demonstrated that both manual polishing and glaze application can prevent significant color alterations on CAD/CAM ceramic surfaces. However, due to the relatively limited amount of evidence to support this conclusion, further studies must be conducted.

Morphological and chemical effects of in-office and at-home desensitising agents containing sodium fluoride on eroded root dentin.

OBJECTIVE: The aim of this study was to evaluate the morphological and chemical effect of in-office and at-home desensitising agents containing sodium fluoride (NaF) on eroded root dentine in vitro. METHODS: Fifty bovine dentine samples were pre-eroded and randomised into five groups (n = 10): G1 (Control) - milli-Q water; G2 - fluoride varnish containing NaF 22,500 ppm; G3 - desensitising cream containing NaF 9,000 ppm associated with 20% nanohydroxyapatite; G4 - toothpaste with NaF 5,000 ppm associated to tricalcium phosphate; G5 - toothpaste containing NaF 900 ppm and casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF). The specimens were submitted to erosive challenge for three days. The analyses were performed using non-contact profilometry for volumetric (Sa) and linear roughness (Ra) followed by scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS). The data were analysed by Kruskal-Wallis and Wilcoxon tests (α = 0.05). RESULTS: There was a significant reduction of Ra and Sa for the eroded samples from the G2 and G5 (p < 0.05) after an erosive challenge. The dentine surface topography pattern showed partially or totally occluded dentinal tubules after treatments, except in the control group. The control, G4 and G3 groups showed a reduction in the dentine inorganic content percentage of Ca (Calcium) and P (Phosphorus) minerals. CONCLUSION: The fluoride varnish and CPP-ACPF toothpaste were able to prevent morphological changes and were the only materials that showed the Ca and P content increased after treatment. These materials may be promising alternatives in the clinical control of dentin erosion.

Accuracy of near-infrared light transillumination (NILT) compared to bitewing radiograph for detection of interproximal caries in the permanent dentition: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the accuracy of the near-infrared light transillumination (NILT) for the detection of interproximal dental caries in permanent dentition when compared to bitewing X-ray (BW). DATA: In vivo studies that detected interproximal primary caries in permanent teeth by using NILT and BW were selected. QUADAS-2 was used to assess the risk of bias. Pooled sensitivity and specificity forest plots were calculated, summary receiver operator characteristics (SROC) curves were constructed. The certainty of the evidence was rated using the GRADE system. SOURCES: Pubmed, Cochrane Library, Web of Science, Scopus, Lilacs/BBO and grey literature databases were surveyed. STUDY SELECTION: From 1594 retrieved articles, 13 studies were included. Six studies had a low risk of bias and a low level of concern regarding applicability. Four studies had an unclear risk of bias, while three presented a high risk of bias. The meta-analysis of six studies demonstrated that NILT presented good overall accuracy. Of 6110 teeth, 92.3 % (5639) were accurately classified (776 as true positive and 4863 as true negative). The pooled sensitivity was 0.97 (0.96 to 0.98; p = 0.0000; I2 = 93.2 %) with moderate certainty of evidence, and the pooled specificity was 0.91 (0.91 to 0.92; p = 0.0000; I2 = 98.3 %) with high certainty of evidence. Symmetric (0.9837) and asymmetric (0.9836) SROC showed a high discrimination and determination effect of NILT. CONCLUSION: The current literature, with moderate certainty and a middling quality of evidence, demonstrates that NILT presents a reasonably comparable accuracy to that of BW for detecting interproximal carious lesions in the permanent dentition. CLINICAL SIGNIFICANCE: Since NILT presented good overall accuracy for the detection of interproximal primary caries, it could be routinely used in dental check-ups, especially in high-risk caries populations and in patients where the use of radiation should be reduced, like pregnant women or children.

Multidisciplinary aesthetic rehabilitation: case report

Objective: This work aims to report a clinical case that performed the aesthetic rehabilitation of a patient through the integration of different dental specialties (Orthodontics, Periodontics and Dentistry). Case Report: An 18-year-old female patient received compensatory orthodontic treatment for correction of class II malocclusion, overbite and overjet, and interproximal diastema. After orthodontictreatment, a gingivoplasty was performed to remove excess gingival tissue and increase the crown of the teeth, and a frenectomy for the anomalous labial frenulum removal. After periodontal treatment the in-office bleaching was conducted, and the diastema was closed with microhybrid composite resins. Conclusion: It was concluded that multiprofessional planning made possible the aesthetic / functional rehabilitation of the patient.

Objetivo: Este trabalho visa relatar um caso clínico que realizou a reabilitação estética de um paciente por meio da integração de diferentes especialidades odontológicas (Ortodontia, Periodontia e Dentística). Relato do Caso: Paciente do sexo feminino, com 18 anos, recebeu tratamento ortodôntico compensatório para correção de má-oclusão classe II, overbite e overjet acentuados, e diastemas interproximais. Após tratamento ortodôntico, foi realizada uma gengivoplastia para a remoção do excesso de tecido gengival e aumento da coroa dos dentes, e uma frenectomia para a remoção do freio labial anômalo. Após o tratamento periodontal, foi realizado um clareamento dentário de consultório, e o fechamento dos diastemas anterosuperiores e o recontorno da cosméticados dentes com resinas compostas microhíbridas. Conclusão: Concluiu-se que o planejamento integrado multiprofissional possibilitou o êxito da reabilitação estética/funcional do paciente.