^{February 2026 Abstracts}

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Effects of different whitening toothpastes on resin composite: A laboratory study

 

Ömer Çellik, dds, phd, Tuba Tunç, dds, phd  &  Rahime Zeynep Erdem, dds, phd

 

Abstract: Purpose: To evaluate the laboratory effects of different whitening toothpastes on resin composite with respect to color change and surface roughness. Methods: A total of 50 disc-shaped specimens were prepared from a microhybrid composite (Zenchrom). The samples were randomly divided into five groups for the application of four different whitening toothpastes (Opalescence Whitening Toothpaste, Rocs Sensation Whitening, Luis Bien Active Carbon Toothpaste and Sparkly White Herbal Toothpaste) and one non-whitening toothpaste (Signal Anti-Caries Toothpaste) (n=10). For staining, the samples were kept in coffee solution. Then, all samples were brushed 5,000 strokes with a toothbrush device to simulate a 6-month brushing period. Color measurements of the specimens after staining and brushing were performed using a spectrophotometer. Surface roughness measurements were performed using a mechanical profilometer. The Shapiro-Wilk test, one-way ANOVA and Kruskal-Wallis H test were used for the statistical analysis of the data (P<  0.05). Results: Following the brushing procedures, a significant increase in surface roughness was observed in all the samples (P<  0.05). When the roughness values were compared between the groups after 6 months of brushing, a statistically significant increase in surface roughness was observed with Signal Anti-Caries Toothpaste compared to Luis Bien and Opalescence (P< 0.05). In the evaluations of the color changes, all the toothpastes had whitening effects, but no statistically significant difference was detected between the toothpastes with respect to whitening performance (P> 0.05). (Am J Dent 2026;39:2-7).

 

 

 

 

 

 

Mail: Asst. Prof. Ömer Çellik, Department of Restorative Dentistry, Faculty of Dentistry, Dicle University, Diyarbakır, 21000, Turkey.  E-MAIL: dtomercelik@gmail.com

 

 

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Effects of bleaching agents on the surface properties of calcium silicate-based cements

 

Pinar Naiboğlu, dds  &  Tuğba Koşar, dds

 

Abstract: Purpose: To evaluate surface properties of three calcium silicate-based cements (CSCs) after exposure to bleaching agents. Methods: 80 samples of each CSC (Biodentine, MTA Angelus, and MTA Repair HP) were prepared and allocated into four groups (n = 20): three groups were exposed to bleaching agents (sodium perborate, carbamide peroxide, and hydrogen peroxide) three times at 4-day intervals and one control group. The surface microhardness, indentation depth (n=10) and surface roughness (n=10) were measured. The surface morphology and elemental composition was examined using scanning electron microscope-energy dispersive spectroscopy analysis. Results: All bleaching agents induced morphological alterations and affected elemental distribution. Both hydrogen peroxide and carbamide peroxide signi-ficantly reduced the microhardness of all CSCs, with hydrogen peroxide causing significantly greater reduction than carbamide peroxide. Both hydrogen peroxide and carbamide peroxide significantly increased indentation depth of all CSCs, with hydrogen peroxide causing a significantly greater increase than carbamide peroxide. All bleaching agents caused a significant increase in surface roughness of all CSCs, with hydrogen peroxide causing the highest increase, fol-lowed by carbamide peroxide and sodium perborate. In all groups, Biodentine exhibited lower roughness, lower indentation depth, and higher microhardness compared to MTA Angelus and MTA Repair HP. (Am J Dent 2026;39:8-15).

 

 

 

 

 

 

Mail: Dr. Pinar Naiboğlu, Department of Restorative Dentistry, Faculty of Dentistry, Giresun University, Giresun, Turkey. E-MAIL: pinar.naiboglu@hotmail.com

 

 

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Effects of grape seed extract, fluoride and Er,Cr:YSGG laser on dentin tubules

 

Kübra Karaçam, dds  &  Rahime Zeynep Erdem, dds

 

Abstract: Purpose: To evaluate the laboratory effects on human dentin tubules of the single or combined use of grape seed extract (GSE), Er,Cr:YSGG laser and fluoride. Methods: Dentin discs were separated into six groups: Group 1 (control), Group 2 (Er,Cr:YSGG laser), Group 3 (fluoride), Group 4 (fluoride+Er,Cr:YSGG laser), Group 5 (GSE), and Group 6 (GSE+Er,Cr:YSGG laser). The number of closed and semi-closed tubules and the tubule diameters in all the samples were evaluated using SEM analysis. Results: In the comparisons of the number of closed dentin tubules, the combined applications (fluoride+Er,Cr:YSGG laser and GSE+Er,Cr:YSGG laser) were seen to be significantly better than the other groups. The most number of closed dentin tubules were observed in Group 4 (fluoride+Er,Cr:YSGG laser). (Am J Dent 2026;39:16-20).

 

 

Mail: Asst. Prof. Kübra Karaçam, Department of Periodontology, Faculty of Dentistry, Afyonkarahisar Health Sciences University, Afyonkarahisar, 03030, Turkey. E-MAIL: kubrakaracam@hotmail.com

 

 

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Acute periapical abscesses in patients with inflammatory bowel diseases

 

Ilan Rotstein, dds  &  Joseph Katz, dmd

 

Abstract: Purpose: To evaluate the prevalence of acute periapical abscesses (PAs) in patients with inflammatory bowel diseases (IBDs). Methods: Integrated data of hospital patients was used. Data from the corresponding diagnosis codes for Crohn’s disease, ulcerative colitis (UC), and PAs were analyzed by querying the appropriate ICD-10 codes in the database. Results: Out of 7,455 Crohn’s patients, 121 were affected with acute PAs. Out of 7,352 UC patients, 115 were affected with acute PAs. In both diseases, females were more affected than males, and whites were more affected than African Americans and other ethnicities. The odds ratio (OR) for acute PAs in patients with Crohn’s disease was 2.69. The OR for acute PAs in patients with UC was 2.51. The difference in prevalence compared to the total hospital patient population was statistically significant (P< 0.0001). In Crohn’s patients, after adjustment for smoking and diabetes co-morbidities, the OR for acute PAs was 1.51 and 2.08, respectively. The difference in prevalence as compared to the total hospital patient population was statistically significant (P< 0.001) and (P< 0.0001), respectively. In UC patients, after adjustment for smoking and diabetes co-morbidities, the OR for acute PAs was 1.44 and 1.46, respectively. The difference in prevalence as compared to the total hospital patient population was statistically significant (P< 0.005). (Am J Dent 2026;39:21-24).

 

 

Mail: Dr. Ilan Rotstein, University of Southern California, DEN 310, Los Angeles, CA 90089, USA. E-MAIL: ilan@usc.edu

 

 

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Comparing the accuracy of three digital impression techniques with conventional impression technique for implant-supported fixed full-arch restorations: A prospective clinical study

 

Zhiran Yuan, msc, Zhuoliang Zhou, dds, ms, Shanwei Ge, msc, Yi Yang, dds, phd, Jiahui Zhu, msc, Rouchen Zhang, msc, Lin Li  &  Ruixia Wang, dds, phd

 

Abstract: Purpose: To compare the accuracy of stereophotogrammetry (SPG), intraoral scanning (IOS), intraoral scanning with prefabricated splint scan body (IOSS) with the conventional impression technique (CI) for implant-supported fixed full-arch restorations. Methods: Four digital files were obtained for each patient’s full arch: a reference scan (laboratory scan of the plaster model obtained by CI) and three test scans (IOS, IOSS, and SPG). The digital files were converted into multi-unit abutment analogs using a digital library. Data were entered into a three-dimensional analysis software to evaluate the distance and angular deviations of the three digital impression techniques relative to the conventional impression technique. Results: A total of 18 edentulous arches were included. Using CI as a reference, SPG exhibited a significant advantage in distance deviation, with significantly lower deviation values compared to IOS and IOSS. Additionally, SPG demonstrated superiority in angular deviation compared to IOS. There were no significant differences between IOS and IOSS in terms of distance or angular deviation. Neither the implant position nor the number of implants significantly affected the distance and angular deviation of SPG and IOSS. However, IOS exhibited increased distance deviation with a higher number of implants, and mandibular implants showed greater location deviation compared to maxillary implants. In all three digital groups, there was no significant correlation between distance and angular deviation with implant system. (Am J Dent 2026;39:25-30).

 

 

Mail: Dr. Ruixia Wang, Department of Dental Implantology, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China.  E-MAIL: wangruixia@njmu.edu.cn

 

 

 

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Influence of underlying resin composite shade and material thickness on color matching of single-shade resin composites

 

Iris de Oliveira Costa, dds, msc, Jade Laísa Gordilio Zago, dds, msc, Cecilia Pedroso Turssi, dds, msc, phd, Fabiana Mantovani Gomes França, dds, msc, phd, Giselle Maria Marchi, dds, msc, phd, Roberta Tarkany Basting, dds, msc, phd  &  Waldemir Francisco Vieira-Junior, dds, msc, phd

 

Abstract: Purpose: To assess the influence of the resin-based substrate shade and the single-shade resin composite thickness on color matching ability. Methods: Discs (Ø6 x 2 mm) made from a conventional resin composite (Z350 XT) simulated high- (B1B), medium- (A3B), and low-luminosity (C3B) substrates. Each disc (n=10) received sequential increments of the following single-shade resin composites: Palfique Omnichroma (PO) or Vittra APS Unique (VU), at thicknesses of 0.5, 1 and 2 mm. Color parameters [CIEL*a*b*, Vita Scale (SGU), ΔE_ab, and ΔE₀₀] were determined for conventional resin composite and post-application measurement of single-shade resin composite thicknesses. Statistical analyses included the Mann-Whitney, Kruskal-Wallis, Dunn, Friedman, or Nemenyi tests (α= 0.05). Results: The ΔE_ab and ΔE₀₀ values were significantly lower for PO than for VU (P< 0.05). At 1 mm, a decrease in L* values were observed for both resin composites and substrates (P< 0.05). The lowest ΔSGU values were recorded on the high-luminosity substrate (B1B), regardless of the applied thickness (P< 0.05). (Am J Dent 2026;39:31-36).

 

 

 

 

Mail: Dr. Waldemir Francisco Vieira-Junior, Department of Restorative Dentistry, Faculty of Dentistry of Piracicaba, State University of Campinas, Avenida Limeira 901, Piracicaba, SP, Brazil. E-MAIL: waljr@unicamp.br

 

 

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Whitening toothpastes for coffee and wine stains: Impact on enamel color and roughness

 

Marina Paparotto Lopes, dds, Iana Maria Costa Gonçalves, dds, msc, phd, Julliana Andrade da Silva, dds, msc, phd, Flávio Henrique Baggio Aguiar, dds, msc, phd  &  Débora Alves Nunes Leite Lima, dds, msc, phd

 

Abstract: Purpose: To evaluate, in the laboratory, the effect of whitening toothpastes Colgate Luminous White Lovers Coffee (CLWC) and Wine (CLWW) on dental enamel stained with coffee and red wine, regarding color (ΔE_ab*, ΔE₀₀, W_ID) and surface roughness (Ra). Methods: 130 samples of bovine incisors were randomly divided into 13 groups (n=10): NC (without staining and brushing); CMP - Colgate Maximum Cavity Protection; CT12 - Colgate Total 12; CLWC – Colgate Luminous White Lovers (Coffee); CLWW – Colgate Luminous White Lovers (Wine); CT12_C - coffee + CT12; CMP_C - coffee + CMP; CLWC_C - coffee + CLWC; NC_C - coffee + distilled water; CT12_W - wine + CT12; CMP_W - wine + CMP; CLWW_W - wine + CLWW and NC_W - wine + distilled water. All analyses were performed twice: Baseline (T0) and 24 hours after brushing protocol (T1). Scanning electron microscopy (SEM) images were obtained. The data were subjected to Shapiro-Wilk normality tests. Kruskal-Wallis and Dunn tests were used for comparisons between groups for color and Ra, and paired Wilcoxon test was used for comparisons between time for Ra. The significance level was 5%. Results: There was a significant difference between groups for ∆E_ab*, ∆E₀₀, and W_ID. CLWW_W group showed significantly greater Ra than NC and NC_C at T1. CLWW_W showed a higher erosion of the enamel surface. CLWC and CLWW promoted effective removal of extrinsic staining when exposed to specific staining with coffee and red wine. However, CLWW increased the enamel surface roughness of the samples stained with red wine. (Am J Dent 2026;39:38-46).

 

 

 

 

 

 

Mail: Dr. Débora Alves Nunes Leite Lima, Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School - University of Campinas, P.O. Box 52, 13414-903, Piracicaba, SP, Brazil.  E-MAIL: dalima@unicamp.br

 

 

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Effect of infection control barriers of light curing units on adhesive

cementation of glass ceramics to enamel

 

Begüm Ünlü Kurşun, dds, Ayşe Atay, dds, phd, Pınar Mavigözlü, dds, phd &  Ebru Karabece Cal, dds, phd

 

Abstract: Purpose: To evaluate the effect of different infection control barriers used with light curing units (LCU) on the shear bond strength (SBS) of glass ceramics with various translucencies and thicknesses during adhesive cementation. Methods: 60 extracted molar teeth cut in halves mesio-distally to obtain 120 enamel surfaces. Lithium disilicate blocks (GC, Initial Lisi Blocks); 30 High Translucency (HT) 0.5 mm, 30 Low Translucency (LT) 0.5 mm, 30 HT 1.0 mm, 30 LT 1.0 mm discs with 3 mm diameter were produced (n=120). Samples were categorized into three groups according to the infection control barriers (n=40): 1-LCU without barrier, 2-Disposable barrier on LCU (Pinnacle Cure Sleeve), 3-LCU wrapped with stretch film. The SBS test was performed after thermocycling. Failure modes were determined at ×20 and classified and statistically analyzed (P< 0.05). Results: Differences between all the groups were significant (P< 0.001). The highest SBS values were obtained as HT LCU 0.5 mm, LT LCU 0.5 mm, HT Sleeve 0.5 mm and LT Sleeve 0.5 mm, respectively. Highest SBS values were seen in HT LCU 0.5 mm (16.51 ± 0.68), while LT 1.0 mm stretch (10.76 ± 1.37) showed the lowest values. Mostly mixed failures occurred in the 0.5 mm sample groups showing higher SBS values. (Am J Dent 2026;39:47-52).

 

 

Mail: Dr. Begüm Ünlü Kurşun, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, Bern 3010, Switzerland.  E-mail:  beguumunlu@gmail.com