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

Wed, 01 Apr 2026 00:00:00 GMT

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

Sun, 01 Mar 2026 00:00:00 GMT

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

Sun, 01 Feb 2026 00:00:00 GMT

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.

Mechanical behavior of tooth-class II restoration complex with various restorative materials using linear and non-linear finite element analysis

Sun, 01 Feb 2026 00:00:00 GMT

Title: Mechanical behavior of tooth-class II restoration complex with various restorative materials using linear and non-linear finite element analysis Authors: Yu, Young-Ho; Jeon, Mi-Jeong; Shin, Su-Jung; Park, Jeong-Won Abstract: This study aimed to investigate the mechanical behavior of the tooth-class II restoration complex restored with composite resin, ceramic, amalgam, and gold using three-dimensional linear and non-linear finite element analyses (FEA). Previous FEA studies generally assumed linear mechanical properties and bonded interfaces between tooth and restorative materials, which differ from clinical reality, particularly for non-bonded restorations such as amalgam and gold. Therefore, in this study, non-linear mechanical properties and non-bonded contact conditions were adopted for different restorative materials. The results showed that the highest enamel and dentin stresses occurred in amalgam restorations, while the lowest were found in ceramic restorations. Amalgam and gold produced higher stress in enamel and dentin compared with composite resin and ceramic. The higher stress observed in amalgam and gold was mainly associated with the non-bonded (frictional) contact condition, because the stresses in these restorations remained below their reported yield strengths under the applied loading conditions. This study provides mechanical insights into the behavior of the tooth-class II restoration complex and offers a possible mechanical interpretation of previously reported clinical observations. These findings should be interpreted within the limitations of the finite element model and do not directly represent clinical outcomes.