Journal of Clinical and Experimental Dentistry最新文献

Background: The risk of pain and flare up following root canal treatment of asymptomatic necrotic teeth remains an unsolved issue despite the recent advances in canal preparation and obturation procedures. The present study evaluated the role of two final irrigations in minimizing such risk. Aim: To compare the effect of final irrigation with antimicrobial - corticosteroid mixture with that of cryotherapy on post-instrumentation pain and microbial reduction in patients with single canalled teeth with necrotic pulps and asymptomatic apical periodontitis.

Material and methods: Twenty-eight patients with asymptomatic necrotic single-canalled teeth participated in the study. After diagnosis, access cavity preparation and chemico-mechanical preparation with rotary files and 2.5% NaOCl irrigation, patients were randomly allocated to receive a final irrigation of either a mixture of levofloxacin, dexamethasone and fluconazole or intracanal cryotherapy. Patients recorded their postoperative pain on an 11-point numerical rating scale up to 72 hours. Microbial samples were collected at 3 stages: preoperatively, post-instrumentation and post- final irrigation.

Results: The two groups showed no significant increase in postoperative pain intensity at all time intervals compared to the preoperative pain intensity. The two groups showed mild pain intensity at 6 and 12 hours postoperatively with no significant difference between them. No pain was reported in both groups at 24, 48 and 72 hours postoperatively. The post-final irrigation samples showed significant bacterial and candidal load reduction in both groups.

Conclusions: Final irrigation with antimicrobial-corticosteroid mixture and cryotherapy following 2.5% NaOCl prevented the rise of the postoperative pain intensity and minimized the intracanal microbial loads with no significant differences between both irrigations.

Background: This study presents a novel numerical evaluation of the bending and torsion behavior of four nickel-titanium glide path instruments, addressing a critical gap in understanding their mechanical performance under clinical conditions.

Material and methods: The evaluated instruments include the WaveOne Gold Glider with a parallelogram cross-section, the R-Pilot with an S-shaped cross-section, the ProGlider with a square cross-section, and the V Taper 2H with a triangular cross-section. Using advanced computer-aided design (CAD) software, detailed geometric models of each instrument were created, followed by numerical simulations performed in the SolidWorks finite element platform. Material properties of nickel-titanium alloys and boundary conditions were defined based on ISO 3630-1 specifications for bending and torsion tests.

Results: The findings revealed significant variations in stress distribution and flexibility among the instruments. Notably, the R-Pilot demonstrated superior flexibility, being approximately 57% more flexible than the WaveOne Gold with a 28 mm deflection during bending. Conversely, the V Taper 2H exhibited the highest stress levels in bending tests. While torsional stress was comparable among V Taper 2H, ProGlider, and WaveOne Gold at approximately 500 MPa, R-Pilot showed the highest stress values under torsional loads. Additionally, distinct differences in stress distribution were observed between reciprocating and rotational glide paths.

Conclusions: These insights underscore the necessity of evaluating both bending and torsion behaviors to optimize the design and clinical performance of glide path instruments.

Background: The integration of digital technologies, such as CAD/CAM systems, into dental practice has significantly transformed both clinical workflows and educational methodologies. However, their incorporation into vocational training programs for Dental Hygiene remains limited. This study aimed to assess the level of familiarity, training, and perceptions related to CAD/CAM technologies and digital workflows among students enrolled in a Higher Technician in Dental Hygiene program.

Material and methods: A cross-sectional survey was conducted with 327 students enrolled in in-person, blended, and online modalities at a vocational training center in Seville, Spain. Data were collected using a validated 34-item questionnaire addressing demographics, digital literacy, and the perceived educational value of digital tools. Statistical analysis was performed using the Chi-square test and Cramér's V.

Results: The sample was predominantly female (91.4%), with participants ranging in age from 18 to over 50 years. While 90.5% reported satisfaction with their academic program, 42.8% were unfamiliar with the term digital workflow, and 53.8% did not recognize the concept of CAD/CAM. Furthermore, 64.2% had received no prior training in digital workflows. Nonetheless, 89.3% of respondents expressed interest in incorporating such technologies into their curriculum, and 81.7% believed that 3D digital tools would be beneficial to their training. Statistically significant associations were observed between digital proficiency and positive attitudes toward the educational and clinical relevance of digital dentistry.

Conclusions: These findings reveal a considerable gap in current curricula, but also a strong willingness among students to adopt technological advancements. Integrating digital workflows and CAD/CAM systems into vocational training programs appears essential to better prepare students and align educational offerings with modern professional standards in dentistry.

Background: The primary aim of this retrospective study was to determine the prevalence of peri-implant bone loss in patients with a documented history of periodontal disease. The secondary aim was to evaluate the influence of various demographic, systemic, and prosthetic variables on marginal bone level changes.

Material and methods: A retrospective analysis was conducted on a cohort of 261 patients treated with implant-supported prostheses at the Rey Juan Carlos University Clinic between 2018 and 2023. Anonymised data were extracted from clinical records and radiographic archives. Variables analysed included age, sex, smoking status, diabetes mellitus, type of prosthesis, use of transepithelial abutments, implant brand, and periodontal history. Bone loss was categorised as none, <1.5 mm, or >1.5 mm. Statistical analysis employed descriptive statistics, Kolmogorov-Smirnov tests for normality, and non-parametric tests (Kruskal-Wallis and Chi-square) using IBM SPSS Statistics, version 25.0.

Results: The overall prevalence of peri-implant bone loss was 24.5%. Within the cohort with a periodontal history (60.5% of patients), the prevalence was 14.5%. Statistical analysis revealed that only the use of a transepithelial abutment (p=0.000) and the implant brand (p=0.001) demonstrated a statistically significant influence on bone loss levels. No significant associations were found with a history of periodontitis alone, age, sex, diabetic status, smoking habit, or type of prosthetic restoration.

Conclusions: Within the limitations of this study, a history of periodontal disease was not a determining factor for increased peri-implant bone loss. The findings underscore the critical importance of prosthetic design, specifically the use of transepithelial abutments, and implant selection in ensuring favourable medium-term outcomes. These results suggest that stringent periodontal therapy and maintenance protocols may mitigate the inherent risks in this patient population.

Background: Cyberbullying, particularly appearance-related harassment, is a growing psychosocial concern among adolescents. Dentofacial features, often targeted in online ridicule, may influence adolescents' health behaviors, including acceptance of orthodontic treatment. Objective: This study examined the association between cyberbullying victimization and orthodontic treatment acceptance among adolescents using a mixed-methods approach.

Material and methods: A convergent parallel mixed-methods design was employed among 200 adolescents aged 12-18 years from schools and orthodontic clinics. Cyberbullying exposure was assessed using the Cyberbullying Victimization Scale, and orthodontic treatment acceptance was measured using a modified 8-item scale. Quantitative analysis included Pearson's correlation and multivariate regression. In-depth interviews with 20 participants were thematically analyzed to explore underlying motivations.

Results: A total of 38.5% of adolescents reported moderate to high cyberbullying exposure, with 23% experiencing appearance-related insults. Adolescents exposed to cyberbullying demonstrated significantly higher orthodontic treatment acceptance scores (31.2 ± 4.3) compared with non-victimized peers (27.6 ± 4.8; p < 0.001). Cyberbullying remained an independent predictor of treatment acceptance ( = 0.39, p < 0.001), explaining 31% of the variance. Qualitative themes revealed that adolescents perceived orthodontics as a strategy to counteract ridicule ("Seeking Change to Escape Bullying") and that online commentary strongly shaped self-perception ("Social Media Mirrors Self-Perception").

Conclusions: Appearance-based cyberbullying significantly influences adolescents' motivation to pursue orthodontic treatment. These findings highlight the need for orthodontists to address psychosocial factors in clinical decision-making and to integrate supportive counseling within treatment planning.

Clinical significance: • Adolescents exposed to appearance-related cyberbullying are more likely to seek orthodontic care, emphasizing the role of psychosocial influences in treatment demand. • Orthodontists should consider screening for cyberbullying experiences during consultations to better understand patient motivations. • Integrating psychological support alongside orthodontic treatment may improve overall well-being and treatment satisfaction.

Background: Finishing and polishing (F/P) procedures are essential for optimizing resin-based restoration esthetics, wear resistance, and surface quality. Bioactive materials like Alkasite and Giomer have attracted attention for their potential clinical benefits, although limited evidence exists regarding the impact of immediate versus delayed F/P protocols on their surface properties. This study assessed how F/P timing and systems influence the surface roughness and microhardness of these materials.

Material and methods: One hundred cylindrical specimens (n=50 per material) were prepared and divided into five subgroups: control (Mylar strip), immediate Sof-Lex, delayed Sof-Lex, immediate Politip, and delayed Politip. Surface roughness was measured using a profilometer, surface morphology was examined with SEM, and microhardness was tested with a Vickers hardness testing. Two-way ANOVA and Tukey's post hoc test were used to analyze the data (p < 0.05).

Results: Control groups exhibited the smoothest surfaces, with Giomer showing significantly lower roughness values than Alkasite across all subgroups. In Giomer, Sof-Lex produced the lowest Ra values, while Alkasite showed no significant differences between protocols. Microhardness results revealed no significant variation between materials regardless of F/P system or timing.

Conclusions: The timing of F/P procedures did not significantly affect the surface roughness or microhardness of Alkasite or Giomer.

Background: The purpose of this in vitro study was to determine the fracture behavior of severely damaged anterior endodontically treated teeth with a core buildup and polyethylene ribbon fiber in different orientations.

Material and methods: Forty human maxillary incisors that had been endodontically treated were prepared to receive a core buildup and divided into 4 groups (n=10): glass fiber post, polyethylene ribbon fiber inserted horizontally, polyethylene ribbon fiber inserted vertically, and core only. The cores were made with short fiber resin composite. The teeth were statically loaded on the palatal surface until fracture, and the failure mode was classified. The mean values of the groups were analyzed by using the Shapiro-Wilk test and 1-way analysis of variance (=.05).

Results: The highest fracture loads were observed in the polyethylene ribbon groups: vertical insertion (677.6 ± 2.4 N) and horizontal insertion (657.1 ± 2.2 N). These were followed by the glass fiber post (421.5 ± 2.2 N) and the core-only group (246.3 ± 4.0 N). The polyethylene ribbon fiber groups were statistically similar (p>0.05). The greatest mean maximum strain, stress, and fracture strength were obtained by the core buildup with polyethylene ribbon fiber inserted horizontally. No significant difference in the fracture strength and maximum stress was found among the glass fiber post, core only, and polyethylene ribbon fiber groups inserted vertically groups (p>0.05). The ratio of catastrophic to non-catastrophic failure was similar for the polyethylene ribbon fiber groups (both 50% - 50%) and for the glass-fiber post (60% - 40%) and core only (70% - 30%).

Conclusions: Cores made with short fiber resin composite with polyethylene ribbon fiber inserted vertically or horizontally can be used as an alternative to conventional post systems.

Background: Piperine piperine extracted from Piper nigrun has a significant potential for use in dentistry and other areas of medical sciences. Promising results concerning this agent in in vitro tests can influence the development of new drugs, medical products, and clinical procedures. The present study aimed to extract, characterize, and evaluate the antimicrobial and antioxidant effect of piperine derived from Piper nigrun.

Material and methods: Extraction of piperine was carried out using a reflux system and confirmed by UV-Vis spectrophotometry and nuclear magnetic resonance spectroscopy. Piperine was diluted in distilled water at 0.001%, 0.002%, and 0.004%. Antioxidant activity of piperine was carried out by analyzing the degree of conversion (DC) in situ of self-adhesive resin cement applied to enamel fragments bleached with 35% hydrogen peroxide. Meanwhile, the antimicrobial activity was assessed using the broth microdilution technique. Statistical analysis of the DC was evaluated with the ANOVA and Student-Newman-Keuls test.

Results: The minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and minimum bactericidal concentration (MBC) were performed with Kruskal-Wallis test. Level of significance adopted was p<0.05. The yield of piperine extraction was 92.86%. No statistical difference between DC values of the piperine groups (0.001%, 0.002% and 0.004%), without whitening group and withening + cemented after 7 days (p>0.05). The whitening + immediate cementation group showed the lowest DC when compared to the other groups (p<0.05). The MBC evidenced antimicrobial activity (p<0.05) at a concentration of 0.004% in comparison with the negative control, without treatment, and the positive control, using chlorhexidine 0.12%. The MFC revealed a reduction in colonies at a concentration of 0.004% when compared to the other groups and controls (p<0.05).

Conclusions: Piperine exhibited antifungal and antibacterial properties and avoided the reduction in the degree of conversion of a self-adhesive resin cement applied on bleached enamel.