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Effect of axiopulpal line angle design and cement space settings on seating accuracy of CAD/CAM ceramic inlays: an in vitro study

2026-07-01T00:00:00Z

Title: Effect of axiopulpal line angle design and cement space settings on seating accuracy of CAD/CAM ceramic inlays: an in vitro study Authors: Kim, Donghwan; Jeon, Mi-Jeong; Kang, Young Suk; Choi, Yu-Sung; Park, Jeong-Kil; Seo, Deog-Gyu Abstract: Objectives: This study investigated the effects of the axiopulpal line angle design and different cement space settings on the adaptation of indirect ceramic inlays. Methods: Standardized Class II cavities were prepared, scanned, and used to design ceramic inlays fabricated with a 5-axis milling unit. Based on the axiopulpal line angle design, the cavities were classified into sharp, rounded, and beveled groups. Each group was further subdivided (n = 10) according to cement space settings as 50, 100, and 50 & micro;m selectively increased to 100 & micro;m at the axiopulpal line angle (50/100 & micro;m). Milling accuracy, occlusal fit, and internal adaptation were examined using the triple-scan method. Statistical analyses were conducted using two-way analysis of variance with Tukey's post hoc test (alpha = 0.05). Results: In the sharp line angle group, the axiopulpal line angle region was under-milled, resulting in positive discrepancies. The 50 & micro;m cement space group demonstrated greater occlusal discrepancies regardless of the axiopulpal line angle design (p < 0.05). Even with increased cement space settings, the sharp line angle group exhibited statistically significant occlusal discrepancies. Nonsharp line angle groups demonstrated significantly smaller internal gaps and greater cement space uniformity when a cement space of 100 or 50/100 & micro;m was applied (p < 0.05). Conclusions: Nonsharp axiopulpal line angle designs improved milling accuracy and occlusal seating, resulting in smaller and more uniform internal gaps in the 100 and 50/100 & micro;m cement space setting. Clinical significance: Nonsharp axiopulpal line angle designs improve milling accuracy and seating in CAD/CAM ceramic inlays. When combined with a 100 & micro;m cement space or selectively increased cement space at the axiopulpal line angle area, thinner and more uniform cement gaps are achieved, which may improve clinical fit and long-term restoration stability.

Clinical Implications of Sterilization Methods Applied to 3D-Printed Implant Surgical Guides: An In Vitro Study

2026-04-01T00:00:00Z

Title: Clinical Implications of Sterilization Methods Applied to 3D-Printed Implant Surgical Guides: An In Vitro Study Authors: Go, Hye-Bin; Kim, Gi-Tae; Yu, Jae-Hun; Yoon, Youngjae; Kwon, Jae-Sung Abstract: Introduction and aims: This in vitro study evaluated how 3 sterilization methods-autoclaving, ethylene oxide (EO) gas, and hydrogen peroxide gas plasma-affect the mechanical, physical, and dimensional properties of 3-dimensional (3D) printed implant surgical guides. These techniques are widely used in dental practice but differ in mechanism and limitations. Methods: Twenty specimens were fabricated using a digital light processing printer and divided into 4 groups (n = 5): non-sterilized control, autoclaving (121 degrees C, 15 minutes), EO gas (55 degrees C, 60 minutes), and hydrogen peroxide gas plasma (<57 degrees C, 18 minutes). Mechanical tests evaluated flexural strength, modulus, and Shore D hardness while translucency and dimensional stability were also assessed. Shape deviation and implant positioning accuracy were compared before and after sterilization. Data were analyzed with one-way analysis of variance and Tukey's post hoc test. Results: All sterilized groups maintained internal fit deviations within clinically acceptable tolerance (+/- 120 mu m), showing no significant differences in overall dimensional accuracy. Implant placement precision was preserved, with implant-tooth distances >= 2 mm. EO sterilization significantly increased the flexural strength (122.49 +/- 10.10 MPa) and modulus (3477 +/- 161 MPa) compared with controls whereas autoclaving showed the lowest strength (92.40 +/- 15.06 MPa). Shore D hardness exceeded 90 HS in all groups, with autoclaving producing the highest values. Only EO treatment significantly reduced translucency. Conclusion: Sterilization method influenced the mechanical and optical properties of 3Dprinted surgical guides without compromising dimensional accuracy. (c) 2026 The Authors. Published by Elsevier Inc. on behalf of FDI World Dental Federation. (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Effects of Oral Health and Functional Characteristics on Taste Sensitivity in Older Adults: Comparative Analysis Using Solution and Taste Strip Tests

2026-03-01T00:00:00Z

Title: Effects of Oral Health and Functional Characteristics on Taste Sensitivity in Older Adults: Comparative Analysis Using Solution and Taste Strip Tests Authors: Jung, Hyo-Jung; Lee, Hye Jin; Cho, Yehin; Ahn, Hyung-Joon Abstract: Background: Taste sensitivity declines with age, adversely affecting dietary intake and quality of life. However, the effects of oral health and function on gustatory ability in older adults remain unclear. Objective: To evaluate the relationship between oral health characteristics and taste sensitivity in older adults using solution and strip-based gustatory tests. Methods: One hundred older adult participants (age: >= 65) were assessed for dental status, denture use, salivary flow, swallowing function, and subjective taste impairment. Taste sensitivity for five modalities was measured using solution and taste strip tests. Statistical analyses included group comparisons and correlation coefficients. Results: Participants reporting subjective hypogeusia exhibited significantly lower total taste scores in solution and strip tests than those without (p < 0.01). Those with < 20 remaining teeth and users of mandibular dentures had lower umami scores than those with more teeth and no mandibular dentures (p < 0.05). Hyposalivation did not affect solution-based scores but was associated with lower total strip test scores (p < 0.05). Swallowing impairment was correlated with lower solution test scores, particularly for salty and umami (p < 0.01). Women had higher salivary flow and umami sensitivity, but overall gustatory function did not differ by sex. Solution and strip test scores were moderately correlated. Conclusion: Taste perception in older adults is differentially influenced by salivary and swallowing functions, and the concordance between solution- and strip-based tests varies according to oral functional status and taste modality. Our results suggest that these methods capture complementary aspects of gustatory function and should be interpreted based on oral function in this population.

Taste Dysfunction in Oral Candidiasis: Impact of Candida Carriage and Hyphal Presence

2026-02-01T00:00:00Z

Title: Taste Dysfunction in Oral Candidiasis: Impact of Candida Carriage and Hyphal Presence Authors: Park, Younjung; Jung, Hyo-Jung; Hwang, Sin Hye; Cho, Eunae Sandra; Ahn, Hyung-Joon Abstract: Background Taste dysfunction is a common symptom of oral candidiasis; however, its underlying mechanisms remain unclear.Objectives This study aimed to determine whether Candida albicans carriage, particularly its hyphal phenotype, is associated with impaired taste sensitivity.Patients/Methods Fifty-seven participants were divided into three groups: noncarriers (n = 20), carriers without hyphae (n = 20), and carriers with hyphae (n = 17). Tongue biofilm samples were collected for Candida culture and smear tests. Salivary flow rates were measured, and taste sensitivity was assessed using standardised taste strips. Carriers underwent topical fluconazole treatment, and post-treatment taste sensitivity was re-evaluated.Results Carriers exhibited reduced sensitivity to sweet and bitter tastes, with an additional decline in umami sensitivity among those with hyphae. In addition, both unstimulated and stimulated salivary flow rates were significantly lower in Candida carriers than in noncarriers. Topical fluconazole treatment resulted in a marked reduction in hyphae and significant improvement in taste sensitivity.Conclusions This study revealed differences in salivary flow and taste sensitivity between noncarriers and Candida albicans carriers. The presence of hyphal forms was strongly associated with greater impairment in taste function. Improvement following antifungal therapy suggests that hyphal invasion may play a key role in the pathogenesis of taste dysfunction in oral candidiasis.