American journal of dentistry最新文献

{"title":"Microhardness, atomic force microscopy and profilometry of dental enamel conditioned with acetic and phosphoric acids.","authors":"Raúl Camacho Rodríguez, Miguel Á Araiza Téllez, Jacqueline A Rodríguez Chávez, Francisco J Alvarado López, Alvaro García Pérez","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To compare the microhardness, microroughness, and topography of the enamel surface via Vickers microhardness, atomic force microscopy (AFM), and profilometry values before and after the use of 32% and 37% acetic acid and 32% phosphoric acid.</p><p><strong>Methods: </strong>Four groups were established: Group 1: control group; Group 2: phosphoric acid gel (Scotchbond Universal Etchant) at 32%; Group 3: 32% acetic acid gel; and Group 4: 37% acetic acid gel. The microhardness was determined with a Vickers indenter (VHN). The topography and microroughness of the enamel were analyzed using 3D images obtained via AFM in tapping mode. Microroughness was determined using a contact profilometer. An ANOVA and paired t-test was used to compare the average VHN and microroughness both before and after the etching of the enamel surface.</p><p><strong>Results: </strong>Statistically significant differences were found for average microhardness after the conditioning of the enamel surface of the four groups (P< 0.001). The roughness obtained via AFM revealed differences among the four groups after the use of the three different acid gels. The profilometry assay showed significant post-conditioning differences among all groups. Conditioning with 32% acetic acid partially modified the characteristics of the enamel surface to a greater extent than conditioning with 37% phosphoric acid; furthermore, the use of acetic acid generated microretentions that could be effective for adhesion.</p><p><strong>Clinical significance: </strong>Acetic acid, an organic biodegradable acid less corrosive than phosphoric acid, can be used to modify the characteristics of the enamel surface, such as microhardness, topography, and microroughness.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 2","pages":"100-104"},"PeriodicalIF":0.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143962867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface roughness of 3D printed and conventional interim restorative materials after dynamic loading.","authors":"Hatice B Özel, Ceren Küçük, Yelda Çiçek","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the surface roughness (Ra; µm) of three different interim resin materials, which were subjected to chewing simulation.</p><p><strong>Methods: </strong>Three interim resin materials were evaluated: (1) LCD type (liquid crystal displays) 3D printed (LCD, n= 10); (2) conventional autopolymerizing bis-acrylic (CO, n= 10); (3) DLP type (digital light processing) 3D printed (DLP, n= 10) interim resin materials. The specimens were subjected to 30,000 cycles of chewing simulation. The surface roughness of the materials was compared and scanning electron microscope (SEM) images representing each group were obtained. The Kruskal-Wallis and Mann-Whitney U test were carried out for comparison of the groups. Paired samples t test was used to compare the Ra values of each group separately before and after chewing simulation (α= 0.05).</p><p><strong>Results: </strong>The mean ± standard deviation values of baseline surface roughness values were 1.252 ± 0.426 for LCD printed resin, 0.715 ± 1.321 for conventional resin, 0.525 ± 0.963 for DLP printed resin. LCD group had the highest Ra 0 values. No statistically significant difference was observed between the CO and DLP group. After 30,000 cycles of simulated chewing, the mean surface roughness values for LCD, CO and DLP groups were 0.992 ± 0.160, 0.524 ± 0.288 and 0.542 ± 0.658, respectively. After chewing simulation, the difference among the Ra1 values of groups were statistically significant (P= 0.014). LCD group had the highest Ra1 values. No statistically significant difference was observed between the CO and DLP group. The difference of Ra values of all interim materials after chewing simulation compared to baseline were not statistically significant.</p><p><strong>Clinical significance: </strong>Since the results showed that the Ra values in this study were above the plaque accumulation threshold Ra of 0.20 µm and SEM images were consistent with the Ra measurements, care should be taken to adequately polymerize and polish the restoration surface, especially when it is being used for an extended period of time.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 2","pages":"67-70"},"PeriodicalIF":0.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143963061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of tooth color, whiteness changes and sensitivity following laser-assisted in-office tooth bleaching using Er,Cr:YSGG laser: A prospective clinical study.","authors":"Athina Tsaltampasi, Dimitrios Dionysopoulos, Dimitrios Strakas, Constantinos Papadopoulos, Effimia Koumpia, Pantelis Kouros, Moschos Papadopoulos, Kosmas Tolidis","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>This prospective clinical study evaluated the tooth color (ΔΕ*ab and ΔΕ₀₀) and whiteness (ΔWID) changes, as well as tooth sensitivity (TS) induced after performing in-office tooth bleaching with or without light-activation of the bleaching gel using Er,Cr:YSGG laser irradiation.</p><p><strong>Methods: </strong>20 subjects were enrolled for the study. The bleaching session was conducted with two 20-minute sessions of a 40% hydrogen peroxide bleaching agent assisted by Er,Cr:YSGG laser (2,780 nm) at the left hemiarch and without laser activation on the right hemiarch. ΔΕ*ab, ΔΕ₀₀ and ΔWID were evaluated in central incisors and canines using a clinical spectrophotometer immediately, 7 days and 30 days after the bleaching procedure. TS was evaluated during the bleaching treatments in both hemiarches of the patients using a visual analogue scale.</p><p><strong>Results: </strong>The results revealed a significant increase in tooth color and whiteness changes following the tooth bleaching in both laser-treated and conventional groups and in all teeth. Tooth color and whiteness changes were observed immediately after the different treatments and were gradually reduced after 7 and 30 days (P< 0.05). Between the conventional and laser-assisted technique, there were statistically significant differences only in canines (P< 0.05) and in lower central incisors (P< 0.05). Mild TS was noticed in 85% of the patients, without differences between the bleaching treatments (P> 0.05).</p><p><strong>Clinical significance: </strong>Er,Cr:YSGG laser-assisted tooth bleaching treatment may enhance tooth color and whiteness changes but not in all the examined tooth types, without inducing more intense tooth sensitivity compared to the conventional technique.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 2","pages":"71-78"},"PeriodicalIF":0.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143963060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of immediate dentin sealing and temporary cement removal methods on microtensile bond strength of a universal resin cement.","authors":"Oğulcan Yücel, Muharrem Erhan Çömlekoğlu, Mine Dündar Çömlekoülu, Ege Çolak, Makbule Heval Şahan","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the impact of different surface cleaning methods and immediate dentin sealing (IDS) on the bond strength of a universal adhesive resin cement to dentin, using a 3D-printed restorative material.</p><p><strong>Methods: </strong>Extracted human third molars were prepared and divided into two groups: with and without IDS. Temporary restorations were cemented onto the prepared tooth surfaces. Five surface cleaning methods were applied to both groups: pumice, pumice with soap, sandblasting, EDTA, and laser. 3D printed resin blocks were fabricated and bonded to the teeth using a universal adhesive resin cement. After thermal cycling and water storage, microtensile bond strength tests were conducted. Failure modes were analyzed using light microscopy and SEM. Statistical analyses were made.</p><p><strong>Results: </strong>Microtensile bond strength (µTBS) was significantly influenced by both surface cleaning methods and IDS application. Sandblasting and laser cleaning resulted in the highest µTBS values, particularly when combined with IDS. IDS significantly increased µTBS compared to the control group, regardless of the cleaning method. SEM analysis revealed that adhesive failure was the predominant failure mode in most groups, with some mixed failures observed.</p><p><strong>Clinical significance: </strong>Prepared tooth surface cleaning procedures increased the microtensile bond strength of the universal adhesive resin cement regardless of immediate dentin sealing.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 2","pages":"79-86"},"PeriodicalIF":0.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143953660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical effects of stannous fluoride dentifrice on peri-implant mucositis, plaque microbiome, and oxidative stress.","authors":"Malgorzata Klukowska, Niranjan Ramji, Alejandra Muñoz Bodnar, Ping Hu, Hao Ye, Sancai Xie, Lijuan Li, Julie Ashe, Tim Reichling, Jiazhen Wang, Kimberly Milleman, Jeffery Milleman","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>This single-center, single-treatment, 4-week study evaluated the efficacy of a stannous fluoride (SnF₂) dentifrice in reducing peri-implant mucositis while assessing changes in biomarkers and the oral microbiome profile.</p><p><strong>Methods: </strong>24 healthy participants 18 years of age or older with osseointegrated implants were included, with 19 participants having mucositis and five without mucositis. The non-mucositis participants served as a reference group for microbiome and biomarker assessments (baseline comparison). All participants used the same 0.454% SnF₂ dentifrice (Crest Pro-Health Sensitive and Enamel Shield) and a soft manual toothbrush twice daily throughout the study. Participants received Modified Gingival Index (MGI) and Gingival Bleeding Index (GBI) assessments at Baseline - Day 1 and at Week 4 - Day 1. Subgingival plaque and peri-implant crevicular fluid (PICF) were collected on Baseline - Day 2 and Week 4 - Day 2 for oxidative stress markers, bacterial endotoxins, proinflammatory cytokines and 16S analysis.</p><p><strong>Results: </strong>After 4 weeks, participants with mucositis experienced a significant reduction from baseline in MGI and GBI scores (63.4% and 79.3%, respectively) and in the number of bleeding sites (72.5% based on GBI analysis). Microbiome analysis of subgingival plaque showed that mucositis was associated with a higher relative abundance of disease-associated genera (Fusobacterium, Porphyromonas, Treponema, and Prevotella) and a lower relative abundance of commensal genera (Rothia and Actinomyces). Alpha diversity was higher in the mucositis group compared to the non-mucositis group at baseline. By Week 4, the profile of participants with mucositis had shifted to align more closely with that of non-mucositis participants. Participants with mucositis showed significant reduction in biomarkers related to bacterial insult, plaque virulence, oxidative stress, and inflammation. Simulated pathway and process analysis revealed that multiple categories of genes were associated with a state of mucositis, and 4 weeks of use of the experimental dentifrice downregulated several virulence-associated genes.</p><p><strong>Clinical significance: </strong>In participants with mucositis, use of a SnF₂ dentifrice for 4 weeks reduced clinical signs and key biomarkers of peri-implant inflammation and shifted the oral microbiome toward a healthier profile, highlighting the utility of SnF₂ dentifrice in the control of peri-implant mucositis.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 2","pages":"59-66"},"PeriodicalIF":1.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of calculus removal with hand and ultrasonic instruments on titanium surfaces.","authors":"Maggie E Eslinger, Vrushali Abhyankar, Franklin Garcia-Godoy, Brian R Morrow, Pooja Ajitsankardas","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the impact of different instruments on dental implants on titanium discs and simultaneously test how effective they were in removing calculus.</p><p><strong>Methods: </strong>Artificial calculus was applied on 36 rectangular areas demarcated on titanium discs. Surface roughness was measured using a stylus profilometer. Calculus was then removed using six different hand or power-driven ultrasonic instruments. Surface roughness measurements D-Ra and D-Rz were then re-calculated. Cleaned distance was divided by total calculus to yield a cleaning ratio and the number of cleaning strokes required to remove the calculus was calculated. All measurements were statistically analyzed independently (two-way ANOVA, Holm-Sidak roughness and cleaning ratios Kruskal-Wallis one-way ANOVA on ranks, and Student-Newman-Keuls, α< 0.05).</p><p><strong>Results: </strong>Ultrasonic magnetostrictive instruments were most efficient in calculus removal and demonstrated a statistically high cleaning ratio percentage (P< 0.001) and required the least number of strokes compared to all the other groups. The resin curettes were the least effective in calculus removal and required the greatest number of strokes. When surface roughness values (D-Ra) were compared between different instruments, statistically significant differences were noted between the resin curettes and ultrasonic magnetostrictive groups, with the resin curette group showing lower values and the Ultrasonic magnetostrictive group showing greater values.</p><p><strong>Clinical significance: </strong>Current research on significance of titanium particles and their possible role in causing periimplantitis emphasizes the importance of using instruments that do not damage the implant surface. Instrumentation causing the least amount of surface roughness should be considered since the risk of damaging the surface outweighs the benefit.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 1","pages":"22-26"},"PeriodicalIF":0.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bond strength evaluation of universal adhesives applied in etch-and-rinse mode on sound and irradiated dentin.","authors":"Anh D Nguyen, Sina Broscheit, Dirk Vordermark, Kerstin Bitter, Reinhard Gerlach, Christian R Gernhardt","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the laboratory microtensile bond strength (µTBS) of universal adhesives applied in etch-and-rinse mode on irradiated and sound human dentin.</p><p><strong>Methods: </strong>Dentin specimens of 135 freshly extracted human third molars were divided in three superordinate groups. Each tooth received either no irradiation (control group), 5 Gy (2 Gy/2 Gy/1 Gy in 3 consecutive days) or the high-level therapeutic dose of 60 Gy (test groups) applied fractionally (2 Gy/day, 5 days/week, 6 weeks). Samples from each group were randomly divided into three subgroups assigned to three established universal adhesives (Futurabond U, AdheSE Universal, Xeno Select) in just the etch-and-rinse application mode (n= 15). Bond strength was assessed with a universal testing machine 15 minutes after application and light curing of the adhesive materials. Statistical analysis was performed using a two-way ANOVA (P< 0.01) and Tukey's test (P< 0.05).</p><p><strong>Results: </strong>Regarding all experimental groups ANOVA showed significant effects on µTBS of dentin irradiation and the used adhesives (P< 0.01, ANOVA). In nearly all groups, a decrease of µTBS was observed when used on highly irradiated dentin. However, comparing the different groups, no significant influence of high-level radiation on the microtensile bond strength of the three universal adhesives assessed in etch-and-rinse application mode could be determined (P> 0.05, Tukey's test).</p><p><strong>Clinical significance: </strong>Within the limitations of this laboratory study, no significant effects of low- and high-level tumor irradiation on the bond strength of universal adhesives can be detected after application in etch-and-rinse mode. Consequently, this mode of application may be considered a viable option for patients who have undergone radiation therapy when using universal adhesive systems for luting restorative materials.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 1","pages":"15-21"},"PeriodicalIF":1.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bond strength of different resin-based cements to 3D-printed permanent restorations.","authors":"Engin Kariper, Aylin Cilingir","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the shear bond strength of different primers with adhesive cements to 3D printed restorations.</p><p><strong>Methods: </strong>72 3D-printed restorations (Formlabs permanent crown resin) and nano-hybrid composite (Tetric EvoCeram) resin cylinders prepared and assigned to two groups, according to G-Multi Primer (GMP) with G-Cem One (GCO) and Clearfil ceramic primer plus (CCP) with Panavia F2.0 (PF) cements and three subgroups (n=9) were created for each cement: (1) control group, (2) 5,000 thermal cycles, (3) 10,000 thermal cycles. 3D-printed restorations were embedded in Teflon molds and cemented with nano-hybrid composite resin cylinders and a shear bond strength test was performed according to group. Failure modes were observed with stereomicroscope (30x), and surface morphology was evaluated with SEM analysis (100x and 2,000x). Statistical analysis was performed using Kolmogorov-Smirnov and Shapiro Wilks tests, and for evaluating the study data, 2-way ANOVA test and post hoc Tukey HSD test were used.</p><p><strong>Results: </strong>The GCO groups exhibited significantly higher SBS values than the PF groups in the bonding of the tested 3D-printed restorations. There was no statistically significant difference in the bond strengths of tested GCO cement groups. A control group of PF cement showed significantly higher SBS values than the 5,000 and 10,000 cycling of PF groups. However, there was no statistically significant difference in the 5,000 and 10,000 cycling PF groups. The bonding performance was superior for the GCO group.</p><p><strong>Clinical significance: </strong>This study showed that exposure to gutta-percha solvents (chloroform, orange oil and Endosolv) for 5 minutes did not affect the bond strengths of both iRoot SP (bioceramic sealer) and AH Plus (resin sealer) to root dentin.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 1","pages":"39-45"},"PeriodicalIF":0.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of bisphosphonates on periodontal diseases in menopausal and postmenopausal women: A systematic review and meta-analysis.","authors":"Linlin Qin, Xinyue Wu, Kunshuang Wu, Hanyue Mai, Ping Wang","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To systematically evaluate the effect of bisphosphonates on periodontal diseases in menopausal and postmenopausal women.</p><p><strong>Methods: </strong>Databases (PubMed, Embase, Web of Science, Cochrane Library databases, Chinese Scientific and Technological Journal database, Wan Fang Data, China Biomedical Literature Database, and Chinese National Knowledge Infrastructure) were searched from inception to July 2024, languages are Chinese and English. Randomized controlled trials (RCTs) reporting the effect of bisphosphonates in menopausal and postmenopausal women with periodontitis were included. The risk of bias was performed using the Cochrane collaboration tool. The primary outcome was clinical attachment loss (CAL), and the secondary outcomes were probing depth (PD) and gingival index (GI). The analysis of the data was performed using Rev Man 5.3 and Stata 16.0.</p><p><strong>Results: </strong>The meta-analysis incorporated four studies that fulfilled the inclusion criteria. In evaluating the efficacy of bisphosphonates against control treatments, there was high heterogeneity observed in CAL (P = 0.0002; I² = 85%) and PD (P< 0.00001; I² = 93%) within the study groups. Meta-analysis showed a significant improvement in CAL gain (MD = - 0.57 mm; 95% CI = -1.04 to -0.11 mm; P< 0.05), PD reduction (MD = - 0.50 mm; 95% CI = -0.96 to -0.05 mm; P< 0.05), and GI reduction (MD = -1.11; 95% CI = -1.22 to -1.01; P< 0.00001) for bisphosphonate treatment vs. bisphosphonate-naïve therapy.</p><p><strong>Clinical significance: </strong>Bisphosphonate treatment seems to be beneficial for managing periodontitis in menopausal and postmenopausal women.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 1","pages":"33-38"},"PeriodicalIF":0.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of remineralization product on the microhardness and surface roughness of enamel after bleaching agents.","authors":"Dilan Kopuz, Özlem Erçin, Dilek Tağtekin, Funda Yanikoğlu","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the effect of toothpaste containing sodium fluoride, a commercially available remineralization product, on the microhardness and roughness of enamel after whitening with two different concentrations of hydrogen peroxide.</p><p><strong>Methods: </strong>32 premolar teeth extracted for orthodontic reasons were collected. Initial microhardness and roughness values were measured. All samples were immersed in a coffee solution for 1 week to simulate coloration in the oral environment and ensure standardization. Then, the second microhardness and roughness measurements were obtained. Two samples were separated, and the remaining ones were divided into three groups; Group 1: Group 2: Samples treated with Beka HP 30% bleaching agent; Group 3: Samples kept in distilled water. For Groups 1 and 2, the bleaching procedure was applied in three sessions of 15 minutes each, following the manufacturer's instructions. Afterward, measurements of all samples were repeated. To examine the reversibility of surface changes following the bleaching process, a demineralization-remineralization (pH) cycle was applied. Subsequently, microhardness and roughness measurements were repeated, and two samples from each group were set aside for FE-SEM Field emission scanning electron microscope analysis. A total of eight samples underwent FE-SEM analysis at x1,000 and x5,000 magnifications. Data were analyzed using two-way ANOVA and Kruskal-Wallis tests.</p><p><strong>Results: </strong>Initial microhardness values of all samples were the highest values, with a decrease observed after the bleaching procedure. Even though the microhardness of the samples increased in Groups 1 and 2 after the pH cycle, there was no significant difference (P< 0.05). While the roughness values of the samples decreased after the discoloration (P> 0.05), they increased after the pH cycle and there were significant differences between the 4th measurement and the other measurements (P< 0.05).</p><p><strong>Clinical significance: </strong>The bleaching agent causes changes in the structure of the enamel and reduces microhardness and roughness values. However, remineralizing agents applied during the pH cycle may have a positive effect on microhardness.</p>","PeriodicalId":7538,"journal":{"name":"American journal of dentistry","volume":"38 1","pages":"9-14"},"PeriodicalIF":0.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}