Journal of Clinical and Experimental Dentistry最新文献

{"title":"Masseter Muscle Thickness and Mandibular Trabecular Complexity: A Cross-Sectional Study.","authors":"Diego De Nordenflycht, Camila Antúnez","doi":"10.4317/jced.64184","DOIUrl":"10.4317/jced.64184","url":null,"abstract":"<p><strong>Background: </strong>To evaluate the association between masseter muscle thickness and mandibular trabecular complexity in subjects with and without myogenous temporomandibular disorders (TMDs).</p><p><strong>Materials and methods: </strong>A cross-sectional study was conducted including 77 participants (41 controls and 36 with TMD). Masseter muscle thickness was measured using ultrasonography, and fractal analysis was performed on panoramic radiographs. Associations were assessed using Spearman correlation and linear regression models. Multivariable analyses were adjusted for age, sex, and diagnostic group.</p><p><strong>Results: </strong>A weak positive correlation was observed between masseter thickness and fractal dimension ( = 0.255, p = 0.025). In unadjusted regression, masseter thickness was significantly associated with fractal values (p = 0.019). However, this association was attenuated and no longer statistically significant after adjustment for age, sex, and diagnostic group (p = 0.091). Sex was significantly associated with masseter thickness (p &lt; 0.001) but not with fractal dimension. In contrast, TMD was independently associated with higher fractal dimension values (p = 0.011). No significant interaction between masseter thickness and diagnostic group was observed.</p><p><strong>Conclusions: </strong>Masseter muscle thickness shows a weak association with mandibular trabecular complexity that varies according to demographic factors. In contrast, TMD is independently associated with higher fractal dimension values, suggesting that mandibular bone microarchitecture is associated with complex functional and clinical influences beyond muscle morphology alone.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e903-e910"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386446/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-Cementation Sensitivity of Zirconia Crowns: A Comparative Clinical Study of Glass Ionomer and Self-Adhesive Resin Cements.","authors":"Rajmonda Halili, Sebahate Hamiti Alidema","doi":"10.4317/jced.64124","DOIUrl":"10.4317/jced.64124","url":null,"abstract":"<p><strong>Background: </strong>This clinical study evaluated post-cementation sensitivity after zirconia crown cementation using two luting agents: a conventional glass ionomer cement (Fuji I) and a self-adhesive dual-cure resin cement (Calibra Ceram).</p><p><strong>Materials and methods: </strong>A total of 40 patients requiring zirconia crown restorations were included in the study and randomly allocated to one of two groups according to the luting cement used. In Group I, zirconia crowns were cemented with conventional glass ionomer cement (Fuji I), whereas in Group II they were cemented with self-adhesive dual-cure resin cement (Calibra Ceram). Post-cementation sensitivity was assessed using a visual analogue scale (VAS) at 2 hours after cementation and after 14 days. Sensitivity was evaluated in response to cold, heat, and biting stimuli. Normality was assessed using the Shapiro-Wilk test. As the data were not normally distributed, intragroup comparisons were performed using the Wilcoxon signed-rank test and intergroup comparisons using the Mann-Whitney U test (p &lt; 0.05).</p><p><strong>Results: </strong>At both evaluation times, the Fuji I group showed higher sensitivity scores than the Calibra Ceram group for cold, heat, and biting stimuli. Cold and heat sensitivity decreased significantly from baseline to day 14 in both groups. For biting sensitivity, a significant reduction was observed in the Fuji I group, whereas the reduction in the Calibra Ceram group was not statistically significant. Between-group comparisons showed significantly lower sensitivity scores in the Calibra Ceram group for all tested stimuli at both time points.</p><p><strong>Conclusions: </strong>Within the limitations of this clinical study, zirconia crowns cemented with self-adhesive resin cement showed lower post-cementation sensitivity than those cemented with conventional glass ionomer cement. The type of luting cement may therefore influence early postoperative sensitivity and patient comfort following zirconia crown cementation.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e848-e853"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386449/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calcium hydroxide removal using ultrasonic-activated acetic acid versus ultrasonic-activated sodium hypochlorite: A randomized ex vivo study with dual microscopy evaluation.","authors":"Angie Tous-Oviedo, Angelica Navarro-Camejo, Dylan González-Arrieta, Jacobo Ramos-Manotas, Luisa Barriga-Periñán, Jaime Plazas-Román, Carlos M Ardila","doi":"10.4317/jced.63951","DOIUrl":"10.4317/jced.63951","url":null,"abstract":"<p><strong>Background: </strong>Incomplete calcium hydroxide (Ca(OH)2) removal represents a significant clinical challenge that compromises endodontic obturation quality by interfering with sealer penetration and poteatouso@unicartagena.edu.contially leading to treatment failure. Despite advances in irrigation techniques, the complete elimination of Ca(OH)2 remains difficult, particularly in anatomically complex regions. Acetic acid (AA), a weak organic acid with demonstrated antimicrobial properties, has been proposed as a cost-effective alternative to sodium hypochlorite (NaOCl) for dissolving alkaline residues due to its acidic pH and superior theoretical capacity for acid-base neutralization reactions. This study aimed to compare the calcium hydroxide removal efficacy of ultrasonic-activated 5% acetic acid versus ultrasonic-activated 5.25% sodium hypochlorite across different root canal thirds using dual microscopy evaluation.</p><p><strong>Material and methods: </strong>Thirty-eight single-rooted premolars were instrumented, medicated with calcium hydroxide for 7 days, and randomly allocated to ultrasonic-activated 5% acetic acid or ultrasonic-activated 5.25% sodium hypochlorite (n=19/group). Removal capacity was evaluated using stereomicroscopy and scanning electron microscopy across coronal, middle, and apical thirds. Data were analyzed using the Mann-Whitney U test and multivariate logistic regression (=0.05).</p><p><strong>Results: </strong>In the middle third, ultrasonic-activated acetic acid achieved superior removal (52.7% excellent/good vs 15.8%; p=0.017; OR=6.00, 95%CI:1.40-25.85) with adequate power (1-=0.82). Multivariate regression confirmed irrigant type as an independent predictor (adjusted OR=4.23, p=0.026) with significant irrigant×third interaction (p=0.041). No differences were observed in coronal (p=0.150) or apical thirds (p=0.820).</p><p><strong>Conclusions: </strong>Ultrasonic-activated acetic acid demonstrated superior calcium hydroxide removal in the middle third compared to ultrasonic-activated sodium hypochlorite. Acetic acid represents an accessible, cost-effective alternative for intracanal medicament removal.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e854-e864"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386440/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of Electronic Apex Locators, Root ZX3, NovApex N31, and Apex-S, in Irrigant Solutions of Varying Conductivity.","authors":"Lucas Rodrigues de Araújo Estrela, Luciano Tavares Ngelo Cintra, Bruno Correa Azevedo, Giuliano Caixeta Serpa, Patrícia Correa Siqueira, Júlio Almeida Silva, Daniel Almeida Decurcio, Carlos Estrela","doi":"10.4317/jced.63279","DOIUrl":"10.4317/jced.63279","url":null,"abstract":"<p><strong>Background: </strong>The success of root canal treatment depends on precise control of the working length (WL), as it directly influences periapical healing and long-term prognosis. Optimal outcomes are achieved when obturation ends short of the radiographic apex, which requires accurate WL determination. This study evaluated the performance of electronic apex locators (EALs) in irrigant solutions with different electrical conductivities.</p><p><strong>Materials and methods: </strong>Twenty human mandibular central incisors were assessed using Root ZX3®, NovApex N31®, and Apex-S®. Standardized reference lengths were established from the incisal edge to the root apex with a digital micrometer (DM). A size 15 K-file attached to each EAL was inserted into the canals until the devices indicated the apical foramen. The silicone stoppers were adjusted to the incisal edge, and the files were removed to measure the length with the DM. The differences between the lengths measured by the EALs and the actual WL were calculated. Statistical analysis was performed using the Friedman test followed by Tukey's post-hoc test, and the Kruskal-Wallis test with the Student-Newman-Keuls post-hoc test. The significance level was set at = 0.05.</p><p><strong>Results: </strong>Root ZX3® showed the highest accuracy (p &lt; 0.05), regardless of the irrigating solution tested. No significant differences were found between NovApex N31® and Apex-S® (p &gt; 0.05). When deionized water was used, both NovApex N31® and Apex-S® demonstrated minimal interference, whereas significant differences were observed with 2.5% NaOCl and Triton®.</p><p><strong>Conclusions: </strong>Root ZX3® demonstrated consistent accuracy across all irrigating solutions. NovApex N31® and Apex-S® performed similarly in deionized water but showed differences when compared with 2.5% NaOCl and Triton®.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e881-e888"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386434/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bilateral Multifocal Nodular Oncocytic Hyperplasia of the Parotid Gland Mimicking Warthin Tumor and Acinic Cell Carcinoma: A Case Report and Literature Review.","authors":"Martín Andura-Correas, Elena Ruiz-Bravo-Burguillos, Guillermo Chacón-Ferrer, Emilia María Montoro-Serrano, Javier González-Martín-Moro, María José Morán-Soto, José Luis Cebrián-Carretero","doi":"10.4317/jced.64152","DOIUrl":"10.4317/jced.64152","url":null,"abstract":"<p><strong>Background: </strong>Multifocal nodular oncocytic hyperplasia (MNOH) of the salivary glands is a rare benign condition that can mimic both benign and malignant neoplasms, posing significant diagnostic challenges. Its bilateral and multifocal presentation is exceptionally uncommon. We present a unique case initially interpreted as bilateral Warthin tumor, later redefined as bilateral acinic cell carcinoma and finally reclassified as MNOH after comprehensive histopathological and immunohistochemical evaluation, and review the literature.</p><p><strong>Case presentation: </strong>A 71-year-old woman presented with a long-standing mass in the left mandibular angle region. Fine-needle aspiration was compatible with Warthin tumor. MRI revealed a well-defined, partially cystic, enhancing lesion in the left parotid gland and a similar nodule in the contralateral gland. A left parotid tumorectomy with synchronous submandibular nodule excision was performed, both initially reported as acinic cell carcinoma (DOG1 positive). Subsequent left total parotidectomy showed multifocal acinic cell carcinoma, with negative FISH for CRTC1/MAML2, ruling out mucoacinar carcinoma. Contralateral MRI revealed multiple nodules with perfusion curves suggestive of Warthin tumor. Right parotidectomy revealed multifocal oncocytic hyperplasia with oncocytomas and extensive clear cell change. Immunohistochemistry demonstrated DOG1 apical positivity, but focal p63 expression and SOX10 negativity favored oncocytic hyperplasia/oncocytoma. Clinicopathologic correlation confirmed the diagnosis of bilateral MNOH.</p><p><strong>Discussion: </strong>This case illustrates the pitfalls in diagnosing oncocytic lesions, where radiology, cytology, and even immunohistochemistry may mimic acinic cell carcinoma. The review of published cases confirms the rarity of bilateral MNOH and highlights the importance of correlating morphology, immunoprofiles, and clinical context.</p><p><strong>Conclusions: </strong>MNOH should be considered in the differential diagnosis of bilateral parotid lesions to avoid overtreatment. Recognition of its histological spectrum, including clear cell and oncocytoma-like features, is essential for accurate diagnosis.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e842-e847"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386452/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro assessment of integrated apex locator systems: working length accuracy, operational parameters, and mechanical effects on NiTi instruments.","authors":"Roberto Barreto Osaki, Raimundo Sales de Oliveira-Neto, Gabriel Nakamura Ramos de Luca, Ricardo Gariba da Silva, Guilherme Ferreira da Silva, Bruno Carvalho de Vasconcelos, Rodrigo Ricci Vivan, Murilo Priori Alcalde, Marco Antonio Hungaro Duarte","doi":"10.4317/jced.64103","DOIUrl":"10.4317/jced.64103","url":null,"abstract":"<p><strong>Background: </strong>This study aimed to evaluate the accuracy of four hybrid endodontic motors-VDW Gold (VDW), iRoot Pro (IRP), E-Connect S (ECS), and TriAuto ZX2 (TZX)-in maintaining length, speed, and angulation during alternating and continuous rotation kinematics and the influence of these parameters on instrument fatigue.</p><p><strong>Materials and methods: </strong>Forty-eight mandibular incisors (n=12 per group) were used to assess apex locator accuracy during glide path procedures with alternating rotation and auto apical stop (AAS) set to the apical foramen (AF: 0.0). Positioning precision was evaluated using micro-CT, while torsional resistance of instruments was tested per ISO 3630-1. Actual speed and angulation were measured using a tachometer and Arduino system. Cyclic fatigue testing was conducted with Only One File 25.08 instruments in an artificial curved canal (60°, 5 mm radius). Data were statistically analyzed with a significance level of 5%.</p><p><strong>Results: </strong>The evaluated devices exhibited similar precision (p&gt;0.05). The TZX showed the lowest number of determinations beyond the AF (p&lt;0.05). Regarding torsional testing, no significant differences were observed between groups (p&gt;0.05). The equipment showed substantial differences compared to the values displayed on the screen (p&lt;0.05). The Optimum Glide Path (OGP) motion provided significantly higher resistance to cyclic fatigue (p&lt;0.05).</p><p><strong>Conclusions: </strong>All hybrid motors were accurate in length control, with TZX being the most conservative. Kinematics did not influence torsional resistance, but significant differences were found between programmed and real parameters.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e921-e928"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386448/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of the Gutta Condensor on Powder-Liquid and Ready-to-Use Hydraulic Sealers.","authors":"Gabriel da Siqueira Felske, Gabriel Barcelos Só, Carolina Horn Troian Michel, Ricardo Abreu da Rosa, Marco Antônio Húngaro Duarte, Jefferson Ricardo Pereira, Marcus Vinicius Reis Só","doi":"10.4317/jced.63891","DOIUrl":"10.4317/jced.63891","url":null,"abstract":"<p><strong>Background: </strong>The purpose of this study was to evaluate the increase in internal and external temperature of bovine tooth roots by driving the Gutta Condensor at two different speeds, as well as whether the sealers activation can cause alterations in the chemical structure of Bio-C Sealer and Cimmo HP, through Raman spectroscopy.</p><p><strong>Materials and methods: </strong>To assess the variation in root temperature, 60 bovine teeth were used. They were sectioned to standardize the samples to a length of 12mm, and their canals were prepared using VDW R50. After preparation, the roots were distributed into 12 groups, based on sealer type, use or non-use of gutta-percha, and Gutta Condensor speed. During root canal filling, internal and external temperatures of the roots were measured in all groups. To access the chemical structure, Raman spectroscopy was performed on both thermally activated and non-activated sealer samples (n=2).</p><p><strong>Results: </strong>It was demonstrated that both the sealer and the gutta-percha influenced the increase in internal and external root temperature. In intragroup comparisons, differences were observed between the speed of the Condensor and the control samples (P &lt; 0.05). Raman spectroscopy showed that both control and activated samples have the same chemical structure.</p><p><strong>Conclusions: </strong>This study concluded that the Gutta Condensor increases both internal and external temperatures to a non-critical point but does not affect the chemical structure of the sealer.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e865-e871"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386450/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative evaluation of microneedling technique and diode laser in gingival depigmentation: A prospective randomized study.","authors":"Natasha Singh, Ruchi Pandey, Nipun Dhalla, Lipika Gopal, Diksha Swaroop","doi":"10.4317/jced.64126","DOIUrl":"10.4317/jced.64126","url":null,"abstract":"<p><strong>Background: </strong>Gingival hyperpigmentation due to increased melanocyte activity is a common esthetic concern. Although several depigmentation techniques exist, recurrence remains a clinical challenge. Minimally invasive approaches such as diode laser and microneedling with ascorbic acid have gained attention. Aim: To compare gingival re-pigmentation following depigmentation using diode laser and microneedling with ascorbic acid.</p><p><strong>Materials and methods: </strong>This randomized controlled study included 32 systemically healthy patients (DOPI 1). Participants were allocated into Group A (diode laser, 940 nm) and Group B (microneedling with topical ascorbic acid). Clinical parameters-Visible Plaque Index (VPI), Modified Gingival Index (MGI), and Dummett-Gupta Oral Pigmentation Index (DOPI)-were recorded at baseline, 3, 6, and 12 months. Pain was assessed using VAS.</p><p><strong>Results: </strong>Both groups showed significant reductions in DOPI from baseline to 12 months (p = 0.0001). Near-complete depigmentation was observed at 3 months, with mild re-pigmentation at 12 months (0.42 ± 0.34 and 0.47 ± 0.22), without significant intergroup differences (p &gt; 0.05). Microneedling showed higher 24-hour VAS scores, but pain resolved in both groups by day 7. VPI and MGI improved significantly in both groups (p = 0.0001).</p><p><strong>Conclusions: </strong>Both modalities are effective, safe, and cost-effective, with comparable long-term outcomes. Diode laser demonstrated lower immediate postoperative discomfort.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 7","pages":"e889-e896"},"PeriodicalIF":0.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386442/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diode Laser Irradiation for Cavity Decontamination: A Pilot In Vitro Study on Antimicrobial Efficacy.","authors":"Francesca Zotti, Giacomo Piersilvio Zocca, Giorgia Lanzaretti, Caterina Signoretto","doi":"10.4317/jced.64128","DOIUrl":"10.4317/jced.64128","url":null,"abstract":"<p><strong>Background: </strong>This pilot study evaluated the potential of a 980 nm diode laser as a viable option for dental cavity decontamination, comparing its antimicrobial effect with 0.2% chlorhexidine.</p><p><strong>Material and methods: </strong>Forty-seven extracted human molars with standardized Class I preparations were sterilized, conditioned with sterile stimulated saliva, and inoculated with Streptococcus mutans. The teeth were arbitrarily assigned to three groups: no treatment (n = 7), chlorhexidine 0.2% for 30 seconds (n = 10), and irradiation with a 980 nm diode laser for 30 seconds (n = 30). After incubation in BHI broth for 24 hours at 37°C, bacterial growth was quantified as CFU/mL using non-parametric tests.</p><p><strong>Results: </strong>Both treatments produced a marked reduction in bacterial growth compared with the untreated group (p &lt; 0.001). Chlorhexidine completely suppressed detectable growth, whereas the laser showed residual contamination in a few samples, though always at much lower levels than the control. The difference between chlorhexidine and laser was not statistically significant (p = 0.253).</p><p><strong>Conclusions: </strong>Despite its small scale, this pilot study indicates that 980 nm diode irradiation can substantially lower S. mutans levels in contaminated cavities. While not conceived as a substitute for chemical disinfectants, the laser presents characteristics that merit attention: no chemical residues, no contribution to bacterial resistance, and potential implications for future adhesive-interface investigations. These aspects may justify further investigation into its use as an adjunctive step within restorative procedures, particularly in protocols aiming to limit chemical agents or to enhance substrate conditioning.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 6","pages":"e785-e791"},"PeriodicalIF":0.0,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13353922/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148421345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Apical Third Enlargement to Different Preparation Sizes and Tapers on Postoperative Pain and Intra-canal Bacterial Reduction: A Randomized Clinical Trial.","authors":"Nermeen Awadallah Abbas, Alaa El-Din Hussein Diab, Manal Mohammed Abd-El Baky, Dina Ahmed Morsy","doi":"10.4317/jced.63543","DOIUrl":"10.4317/jced.63543","url":null,"abstract":"<p><strong>Background: </strong>Apical preparation size plays a vital role in root canal instrumentation, yet the ideal size and taper remain a subject of debate. This randomized clinical trial was designed to assess the influence of different apical preparation sizes and tapers on postoperative pain and intracanal bacterial reduction.</p><p><strong>Materials and methods: </strong>Fifty-six patients, diagnosed with necrotic mandibular premolars, were randomized into two groups according to apical enlargement size (#35 or #45). Each group was further divided by taper (0.04 or 0.06), resulting in four groups. Microbiological samples were collected before and after instrumentation, while postoperative pain was assessed at 6, 12, 24, 48, and 72 hours using the Numeric Rating Scale (NRS). Data analysis involved Kolmogorov-Smirnov and Shapiro-Wilk tests for normality, with Kruskal-Wallis, Friedman, and Fisher's exact tests; statistical significance was set as p &lt; 0.05.</p><p><strong>Results: </strong>At 6 and 12 hours, pain scores differed significantly between groups (p &lt; 0.05), with the highest levels at 6 hours followed by a significant decline by 12 hours (p &lt; 0.05). All treatment groups showed a marked reduction in bacterial counts after instrumentation (p &lt; 0.001). The percentage reduction varied significantly among groups (p &lt; 0.001).</p><p><strong>Conclusions: </strong>Larger apical preparations may induce early postoperative pain, yet improve intracanal bacterial reduction. Increased taper also contributes to enhanced bacterial reduction.</p>","PeriodicalId":15376,"journal":{"name":"Journal of Clinical and Experimental Dentistry","volume":"18 6","pages":"e743-e749"},"PeriodicalIF":0.0,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13353923/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148421320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}