^{October 2025 Abstracts}

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                                                                                                                                             Research Article

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Comparisons of optical characteristics between 3D printed dental resins and resin composites

 

Yong-Shin Hong, dds, phd,  Soyeon Kim, phd,  Muhammad Akira Takashi Dharma, dds, msd,  Wanki Lee, ba, Satoshi Yamaguchi, phd,  Franklin Garcia-Godoy, dds, ms, phd, phd  &  Young-Seok Park, dds, msd, phd

 

Abstract: Purpose: To compare the optical characteristics of 3D-printed resins and conventional resin composites, focusing on color differences, whiteness index, and translucency under varying specimen thicknesses and polishing conditions. Methods: A total of 240 disc-shaped specimens (10 mm diameter, 2-4 mm thickness) were prepared using four brands each of 3D-printed resins and resin composites. Color measurements (L*, a*, b*) were performed using a benchtop spectrophotometer before and after polishing. Color differences (ΔE₀₀) were calculated using the CIEDE2000 formula, and both whiteness index and translucency were assessed. Statistical analyses included paired t-tests and Kruskal-Wallis tests (P< 0.05). Results: Significant color differences were observed among the different brands, even with identical shade designations and polishing conditions. Polishing reduced ΔE₀₀ values but most remained above the acceptability threshold. Resin composites exhibited smaller color differences than 3D-printed resins, while comparisons between the two types showed the largest discrepancies. Translucency decreased with increasing specimen thickness and varied significantly across materials, with 3D-printed resins generally showing higher whiteness indices. The findings suggest a need for greater standardization of optical properties in esthetic restorative materials. (Am J Dent 2025;38:220-227).

 

 

 

 

Mail: Prof. Dr. Young-Seok Park, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea. E-mail: ayoayo7@snu.ac.kr

 

 

 

 

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                                                                                                                                             Research Article

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The effect of commonly used beverages on color change and surface roughness of leucite-reinforced CAD-CAM material with different surface finishing protocols: A laboratory study

 

Zahide Aydin, dds  &  Zeynep Yeşil, dds, phd

 

Abstract: Purpose: To evaluate the laboratory effects of commonly used beverages on the surface roughness and color change of leucite-reinforced Computer Aided Design-Computer Aided Manufacturing (CAD-CAM) material with different laboratory surface finishes. Methods: In this study, all the IPS Empress CAD-CAM ceramic block specimens were treated with a glaze layer and then randomly divided into three groups. The samples (n=25) in Group 1 (Control) were not treated (glaze layer was left). The glaze layer of the other samples (n=50) was abraded by the same researcher. While the samples in Group 2 were treated with Optrafine (optrafine after glazing); those in Group 3 were subjected to surface treatment with Eve polishing kits (Eve kit after glazing). The samples were then immersed in five different beverages (cola, coffee, tea, fruit juice and distilled water) and color (ΔE₀₀) and surface roughness (Ra) measurements were repeated after 18, 36 and 54 hours. Color measurements of all specimens were measured using a dental spectrophotometer and surface roughness (Ra values) through profilometry. Results: ANOVA revealed that the interactions of time, time and surface finishing protocols, time and solution, and the combination of time, surface finishing process, and solution were statistically significant (P< 0.001). The least color change (ΔE₀₀= 0.16) and smoothest surfaces (Ra= 0.38) µm were observed in samples with the glaze surface finishing protocol, while the highest color change (ΔE₀₀=2.54) and surface roughness (Ra=2.17 µm) values were found in samples with the Eve surface finishing protocol. The leucite-reinforced CAD-CAM ceramic samples with a glazed surface finish showed the highest color stability and the lowest surface roughness. Color change was measured within clinically acceptable limits in all groups (AT, ΔE₀₀ ≤ 1.8 ), except for Eve surface-finished tea group (2.54) between 18–36 hours. (Am J Dent 2025;38:228-236).

 

 

 

 

 

 

 

Mail: Dr. Zeynep Yeşil, Department of Prosthodontics, Faculty of Dentistry, Recep Tayyip Erdoğan (Ataturk) University, Rize (Erzurum), Turkey. E-mail: zeynep.yesilduymus@erdogan.edu.tr

 

 

 

 

 

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                                                                                                                                             Research Article

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Evaluation of the effect of expiration date on composite bond strength and color stability

 

Abdurrahman Yalçin, dds, Veysel Eratilla, dds  &  Simge Gümüş Ayaz, dds

 

Abstract: Purpose: To comparatively evaluate the dentin bond strength and color stability of expired and non-expired resin composites (RC). Methods: 48 caries-free teeth were randomly divided into four groups. The specimens were ground to expose the dentin, and an adhesive (GC Premio Bond) was applied and light-cured. RC (GC G-ænial) in shade A2 was applied to each group (according to its expiration date) using a transparent mold (4 mm × 2 mm) and polymerized. Group 1: expired for 2 years; Group 2: expired for 1 year; Group 3: 1 year remaining until expiration; Group 4: 2 years remaining until expiration. The specimens were immersed in distilled water for 24 hours and then placed in a tea solution, with color measurements taken using a spectrophotometer (EasyShade V) on the 1st, 7th, and 28th days. (CIEDE 2000 formula: L* = 94.48, a* = 0.16, and b* = -0.21). After the color measurements, the specimens underwent a shear bond strength test applied to the bonding interface between the tooth and the composite using a universal testing machine and the values were recorded. Results: The E1 measurements exhibited the lowest mean color change (5.88 ± 1.02), whereas the E3 measurements had the highest mean color change value (10.13 ± 3.35). The lowest bond strength was observed in Group 1 (97.25 ± 20.33), while the highest value was found in Group 4 (149.45 ± 32.75). The differences between Group 1 and Groups 3 and 4 were statistically significant. (Am J Dent 2025;38:237-241).

 

 

 

Mail: Dr. Simge Gümüş Ayaz, Department of Prosthetic Dentistry, Faculty of Dentistry, Batman University, 72060 Batman Merkez/Batman, Turkey. E-mail: dtsimgegumus@gmail.com

 

 

 

 

 

 

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Laboratory effects of desensitizing mouthwashes on tooth discoloration and surface roughness

 

Elif Öğüt, dds, ms, Nazlı Gül Kınoğlu, dds, ms  &  Burcu Karaduman, dds, ms, phd

 

Abstract: Purpose: To evaluate the effects of four different mouthwashes, including three desensitizing formulations, one chlorhexidine-based solution, and artificial saliva as the control, on enamel discoloration and surface roughness. Methods: 60 extracted human lower incisors were exposed to the solutions, and measurements were performed before and after exposure using a spectrophotometer (ΔE) and profilometer (Ra). Results: None of the tested solutions caused clinically perceptible discoloration (ΔE < 3.7) nor significant changes in the surface roughness (P> 0.05). Among the desensitizing solutions, the potassium nitrate-containing mouthwash exhibited the highest, albeit not clinically significant, changes in both color and roughness. However, no statistically significant differences were observed among the groups in terms of both ΔE and surface roughness values (P> 0.05). (Am J Dent 2025;38:242-246).

 

 

 

 

Mail: Prof. Dr. Burcu Karaduman, Biruni University, Faculty of Dentistry, Department of Periodontology, Istanbul, Turkey. E-mail: bkaraduman@biruni.edu.tr

 

 

 

 

 

 

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Influence of aging on mechanical and microbiological properties in CAD-CAM-milled and 3D-printed denture base resins

 

Victor Augusto Alves Bento, dds, ms, phd,  João Mateus Cavalaro Sayeg, Cleber Davi Del Rei Daltro Rosa, dds, ms,  Cleidiel Aparecido de Araújo Lemos, dds, ms, phd, Maria Carolina Silva Marques, ms, phd  &  Eduardo Piza Pellizzer, dds, ms, phd

 

Abstract: Purpose: To evaluate the adhesion of Candida albicans and the mechanical properties of resins in denture bases fabricated using conventional, milled, and 3D printing methods at different aging times. Methods: A total of 96 resin samples were manufactured, divided into three resin groups (n=32) (conventional thermally activated, milled and 3D printed), and subdivided into four aging times by thermocycling at temperatures 5± 1°C and 55 ± 1°C in 24 hours, 5,000, 10,000, 20,000 cycles (n= 8), evaluating the adhesion of C. albicans (ATCC90028), surface microhardness (Knoop), flexural strength and elastic modulus by three-point mechanical test. Data were evaluated by two-way ANOVA and Tukey's test for multiple comparisons (P< 0.05). Results: The milled resin demonstrated significantly lower colonization of C. albicans at times T0 (0.50± 1.37) (P= 0.007) and T1 (0.60±1.33) (P= 0.032) compared to other resins. The 3D-printed resin exhibited significantly lower values of surface microhardness at T1 (11.05± 0.26), T2 (10.92±0.63), and T3 (10.21± 0.45) (P< 0.001). The conventional and 3D-printed resins did not show significant differences in flexural strength over time (P> 0.05). The 3D-printed resin exhibited a significant difference in elastic modulus compared to the other resins, notably displaying the lowest value at time T3 (750.36± 29.32 MPa) (P< 0.05). (Am J Dent 2025;38:247-251).

 

 

 

Mail: Dr. Victor Augusto Alves Bento, Federal University of Mato Grosso do Sul, Cidade Universitária, Av. Costa e Silva - Pioneiros, MS, 79070-900, Brazil. E-mail: augusto.alves@ufms.br

 

 

 

 

 

 

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                                                                                                                                             Research Article

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In vitro treatment of oral cancer cells using copper and glucose oxidase-based nanoparticles

 

Hyeong Sun Park, dds, ms, Unchul Shin, dds, ms,  So-Young Park, dds, phd,  Franklin Garcia-Godoy, dds, ms, phd, phd &  Yong Hoon Kwon, phd

 

Abstract: Purpose: To test the in vitro effectiveness of GOx-combined nanoparticles (pvp-Cu-GOx) in treating oral cancer cells under hydrogen peroxide and laser irradiation conditions. Methods: Using polymer, metal, and glucose oxidase, nanoparticles were synthesized. Their ability to kill cancer cells was evaluated through an in vitro cell viability test. Methylene blue (MB) degradation test and DPBF assay were performed to evaluate ROS generation. Oxygen production and glucose consumption were also evaluated. Results: GOx-combined nanoparticles (pvp-Cu-GOx) achieved cancer cell death over 80% in 100 μM H₂O₂. Much degradation of MB solution occurred by pvp-Cu-GOx compared to that of pvp-Cu. Oxygen was produced up to 4.3 mg/L by pvp-Cu-GOx at 200 ppm concentration. pvp-Cu-GOx consumed glucose though not high compared to that by glucose oxidase itself. The obtained results are the combined reactions of ROS and glucose oxidase. (Am J Dent 2025;38:252-256).

 

 

Mail: Prof. Yong Hoon Kwon, Department of Dental Materials, School of Dentistry, Pusan National University, Mulgeum-eup, Yangsan, 50612 Korea. E-mail: y0k0916@pusan.ac.kr

 

 

 

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The role of dentifrices containing different desensitizing agents on erosive tooth wear in dentin and tubule occlusion

 

Tammy Tawil, dds,  Mariana Beraldo Maia, dds, phd,  Raquel Marianna Lopes, Raissa Manoel Garcia, Taís Scaramucci Forlin, dds, phd  &   Ana Cecília Correa Aranha, dds, phd

 

Abstract: Purpose: To analyze the effect of dentifrices containing different desensitizing agents on dentin wear and tubule occlusion. Methods: Dentin slabs from sound human third molars were assigned to six groups (n=10 per group): C- (negative control, distilled water), C+ (regular fluoride dentifrice, without desensitizing agent), SCP (sodium and calcium phosphosilicate/Novamin), ACZP (arginine, calcium carbonate/Pro-Argin and zinc phosphate), FCPS (calcium fluoride phosphosilicate/Biomin), and AC (Pro-Argin). A 5-day erosion/abrasion cycling was conducted, consisting of citric acid exposure (1%, 2 minutes) followed by remineralization by artificial saliva (60 minutes), six times per day and a twice-daily toothbrushing (45 strokes). Surface loss (SL) was measured using an optical profilometer at baseline, and after days 1, 3, and 5. Dentin tubule occlusion was evaluated via environmental scanning electron microscopy (n= 3) at baseline and after the final cycle. Data were statistically analyzed (α= 0.05). Results: No significant differences in surface loss (SL) were observed among dentifrices on days 1 and 3 (P> 0.05), but significant differences emerged by day 5 (P < 0.05). SL increased significantly over time (P< 0.001). For tubule obliteration, no significant differences were found among dentifrices (P= 0.101) or in the interaction between dentifrice and time (P= 0.131), although significant differences were observed over time (P< 0.001). All dentifrices promoted a progressive increase in surface loss (SL) over time. No significant differences were observed among groups on days 1 and 3. By day 5, FCSP and AC showed significantly lower SL compared to the negative control. However, this reduction in SL was not associated with significant differences in dentin tubule occlusion. (Am J Dent 2025;38:257-262).

 

 

Mail: Prof. Ana Cecília Correa Aranha, Department of Restorative Dentistry, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes 2227, São Paulo, SP, Brazil, 05508-000. E-mail: acca@usp.br

 

 

 

 

 

 

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Enhanced shear bond strength of IPS Empress 2 restorations on dentin using MDPB-modified adhesive system: A comparative study

 

Chen Qu, mm, Lijun Chen, bm, Yongliang Zhang, bm  &  Xiangling Liao, phd

 

Abstract: Purpose: To evaluate the shear bond strength of restorative resin agents incorporating the antibacterial monomer methacryloyloxy-dodecylpyridinium bromide (AM-MDPB) when bonding IPS Empress 2 ceramic restorations to dentin. Methods: 216 all-ceramic IPS Empress 2 discs (3 mm diameter, 4 mm height) were prepared with various dual-polymerizing (DP) luting systems, including Panavia F 2.0 and Variolink 2, to cement these restorations to prepared dentin surfaces. The study assessed the impact of a dentin adhesive solution with AM-MDPB (Clearfil Protective Adhesive, CPA) on the shear bond strength of these restorations. Human premolars (n=216) were prepared to expose the dentin surface, which was polished with silicon carbide sandpaper. Specimens were randomly divided into four groups based on luting system and application of CPA. Shear bond strength was measured after thermal cycling, and failure modes were analyzed using an Image Analyzer. The data were analyzed using two-way ANOVA. Results: The findings demonstrated a significant enhancement in the shear bond strength of all DP luting systems to dentin with the application of the antimicrobial adhesive. The mean shear bond strength (SBS) values in MPa for Panavia F 2.0, Panavia F 2.0 with CPA, Variolink 2, and Variolink 2 with CPA were 18.11 ± 2.98, 25.40 ± 7.46, 21.45 ± 4.75, and 29.32 ± 2.37, respectively. Most samples exhibited adhesive failure at the interface between the restorative resin agent and dentin. (Am J Dent 2025;38:267-272).

 

 

 

 

Mail: Dr. Xiangling Liao, Department of Stomatology, Beijing Luhe Hospital Affiliated to Capital Medical University, No. 82 Xinhua South Road, Tongzhou District, Beijing 101149, China. E-mail: liaoxiangling114@163.com

 

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                                                                                                                                                 Review Article

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Application potential of therapeutic ultrasound in oral diseases

 

Fang Wang, phd  &  Dong-Dong Zhang, bed

 

Abstract: Purpose: To review the literature on the application potential of ultrasound in the treatment of various oral and dental diseases. Methods: Two reviewers carried out a computer-based literature search using PubMed and Web of Science to identify papers published up to February 2025. The keywords used in the investigation were “therapeutic ultrasound”, “low-intensity pulsed ultrasound”, and various words related to oral and dental disease (oral submucosal fibrosis, burning mouth syndrome, periodontitis, orthodontic tooth movement, and tooth trauma or caries). Results: Therapeutic ultrasound, particularly low-intensity pulsed ultrasound (LIPUS), showed beneficial effects in interfering with pathological fibrosis, suppressing inflammatory responses, promoting periodontal tissue regeneration, and facilitating the repair of dentin-pulp complex injuries in oral and dental diseases. (Am J Dent 2025;38:263-266).

 

 

 

 

 

 

Mail: Dr. Fang Wang, Center for Cariology, Endodontics and Periodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, China. E-mail: wangfang-nm@whu.edu.cn