Journal of Clinical and Experimental Dentistry最新文献

Bullous pemphigoid (BP) is an autoimmune blistering disorder mainly affecting the elderly. Although primarily cutaneous, bullous pemphigoid can occasionally involve the oral mucosa, which complicates diagnosis and management. We report an 88-year-old woman with diabetes and dementia who presented with tense bullae on her limbs. Systemic corticosteroid therapy improved the skin lesions, but new painful erosions appeared on the hard palate. Although mucosal BP was considered, the concurrent improvement of cutaneous symptoms suggested an opportunistic infection instead. Culture confirmed Candida albicans, and antifungal therapy led to rapid resolution. This case highlights the diagnostic challenge of distinguishing between BP progression and steroid-induced candidiasis. Early detection and proper treatment are essential, especially in elderly, immunocompromised patients. Maintaining oral hygiene through dental collaboration also plays a crucial role in preventing such complications. Our findings underscore the importance of multidisciplinary care and managing infection when treating BP in patients with systemic vulnerabilities. Key words:Bullous pemphigoid, Oral candidiasis, Elderly patient with diabetes.

Background: Nanohybrid resin composites are widely used in esthetic dentistry, and the choice of an appropriate polishing technique can influence their surface properties. The aim of this study was to compare, in vitro, the surface roughness of three nanohybrid resin composites before and after dry and wet polishing.

Material and methods: This in vitro longitudinal experimental study included 60 composite resin discs, evenly distributed into three groups (n = 20): Filtek Z250XT, Opallis, and Tetric N-Ceram. Each group was further divided into two equal subgroups (n = 10) for the application of dry and wet polishing techniques. Surface roughness was measured using a digital profilometer before and after polishing. Independent and paired Student's t-tests were used for statistical analysis, with a significance level set at p < 0.05.

Results: Prior to polishing, no significant differences in average surface roughness (Ra) were found among the resin groups, indicating adequate standardization: Filtek Z250XT (p = 0.899), Opallis (p = 0.585), and Tetric N-Ceram (p = 0.721). Following dry or wet polishing, no significant intragroup differences were observed: Filtek Z250XT (p = 0.066), Opallis (p = 0.124), and Tetric N-Ceram (p = 0.584). When comparing pre- and post-treatment values, Filtek Z250XT showed a significant reduction only with wet polishing (p = 0.003). In contrast, both Opallis and Tetric N-Ceram exhibited a significant decrease in roughness with both polishing methods: dry (p = 0.044 and p = 0.001, respectively) and wet (p < 0.001 for both).

Conclusions: Both dry and wet polishing were effective in reducing the surface roughness of Opallis and Tetric N-Ceram resin composites, whereas in Filtek Z250XT, a significant reduction was observed only with wet polishing. These findings suggest that the effectiveness of the polishing procedure may vary depending on the type of resin composite, which should be considered when selecting clinical finishing and polishing protocols to optimize the surface properties of restorative materials. Key words:Comparative study, Composite Resins, Dental materials, Dental polishing, Surface properties, surface roughness.

Background: Enhancing the adaptation and durability of composite restorations remains a major challenge in modern adhesive dentistry. Recently, a new self-cured resin composite has gained attention with the potential to improve interfacial adaptation and reduce polymerization shrinkage stress, offering an alternative to conventional light-cured systems.

Material and methods: Sixteen freshly extracted human molars were prepared with standardized Class II cavities and randomly assigned to two groups (n=8). The first group was restored using a self-cure bulk-fill resin composite (Stela Automix, SDI Ltd., Australia) with its respective primer, while the second group received an injecTable resin composite (G-aenial Universal InjecTable, GC Corporation, Japan) with a universal adhesive. Restorative procedures followed manufacturers' instructions. The restorations were finished and polished, before being stored in distilled water at 37°C for six months to simulate aging conditions. After storage, specimens were sectioned longitudinally and analyzed using environmental scanning electron microscopy to evaluate internal adaptation, and interfacial gap measurements were recorded.

Results: An independent Sample T-test showed a statistically significant difference in interfacial gap (IG%) between the two restorative systems, with the self-cure composite showing more favourable outcomes. For stela, the IG% was13.5±6.1 while for InjecTable composite IG%=28.4±13.3.

Conclusions: The Stela primer and composite used in this study demonstrated superior internal adaptation compared to the light-cured control, suggesting they could be a viable alternative, particularly for deep gingival margins or situations where light curing is inaccessible. Key words:Self-cure composite, internal adaptation, SEM, curing mode, Universal adhesive.

The term keratoameloblastoma has been used to describe a histologically heterogeneous group of ameloblastoma variants that share the formation of keratin by the ameloblastomatous epithelium. To date, thirty-eight cases of keratoameloblastoma have been previously reported in the literature, nine of which exhibited a papilliferous component. Here we report a new case of a recurrent tumor that falls within the keratoameloblastoma spectrum. It presented as an expansile, solid lesion with internal calcification in the right infratemporal fossa six years after ipsilateral hemimandibulectomy in a 46-year-old white female. Histological evaluation revealed islands of columnar cells resembling ameloblasts surrounding a central area with stellate reticulum-like cells, some of them completely filled with keratin. In addition, areas showed basal ranging from columnar to cuboidal with hyperchromatic nuclei. The clinical, histopathologic, and radiographic features of keratoameloblastoma are reviewed, along with treatment approaches and follow-up considerations. Although only a few cases have been documented, the tumor's aggressive biological behavior and the high recurrence rate suggest that a more aggressive therapeutic approach is warranted. Patients should be informed of the importance of clinical monitoring. Surgical resection with adequate safety margins and histopathological evaluation of the margins is strongly recommended. Key words:Odontogenic tumors, keratoameloblastoma, ameloblastoma, review.

Background: The increasing demand for minimally invasive aesthetic procedures, particularly botulinum toxin type A (BTX-A) injections, has expanded the scope of dental practice to include facial aesthetics. However, the safe and effective administration of BTX-A requires a thorough understanding of facial anatomy, including the topographic relationships of muscles, skin layers, and vascular structures. This cross-sectional study aimed to identify the primary anatomical concerns and knowledge gaps among dentists performing BTX-A injections.

Material and methods: A structured questionnaire was distributed to 316 dentists, assessing their confidence and knowledge regarding facial anatomy and BTX-A application.

Results: A total of 62% of participants had specialized training, while 37% had attended BTX-A-specific courses. Notably, professionals with specialized training demonstrated significantly greater confidence and anatomical knowledge compared to their non-specialized counterparts. Key areas of concern included the corrugator supercilii, levator labii superioris alaeque nasi, orbicularis oculi, frontalis, and platysma muscles, as well as the facial artery's location and depth. Over 80% of respondents reported limited or insufficient knowledge in these areas, highlighting a critical need for enhanced anatomical education and practical training.

Conclusions: The study underscores the importance of integrating facial anatomy and injection techniques into dental curricula and continuing education programs to ensure patient safety and optimize treatment outcomes. By addressing these knowledge gaps, dentists can confidently expand their practice to include BTX-A applications, contributing to the growing field of orofacial harmonization. Key words:Botulinum toxin type A, Facial anatomy, Dental practice, Cosmetic Dentistry; Esthetic Dentistry.

Background: Diagnosing and clinically managing vertical root fractures (VRF) present ongoing challenges for dentists. This study aimed to assess the diagnostic approaches and the clinical management employed by Brazilian dentists when confronted with suspected cases of VRF.

Material and methods: Online questionnaires were sent to dentists via social media and email. The questionnaire consisted of seven inquiries about the diagnosis and clinical management of suspected VRF cases. The data were evaluated descriptively and statistically using the Chi-square, Fisher's exact and Kruskal-Wallis tests (p<0.05).

Results: A total of 517 dentists answered the questionnaire, 72.3% were Endodontists, 17.41% were general practitioners, and 10.25% were specialists in other dental fields. A narrow and deep periodontal pocket was the most frequently reported clinical sign (71.8%), while a halo-shaped radiolucency was the most common radiographic finding reported (59.3%). 85.7% of the participants reported requesting a cone-beam computed tomography (CBCT) scan to VRF suspected cases, and the combination of four complementary exams was most frequently selected by dentists (23.59%). Professional qualification influenced the number of clinical signals and of auxiliary exams reported in VRF suspected cases (p<0.05). 91.9% of the participants reported using both the image and the CBCT report to evaluate the scan, and no association was observed between dentist qualifications and CBCT evaluation methods (p<0.05). 308 participants indicated extraction for teeth suspected of VRF, whereas 90 suggested surgical exposure, with 79 of them being Endodontists. A significant association was observed between dentist qualifications and clinical management in suspected VRF cases (p<0.05).

Conclusions: A variety of clinical and radiographic signals and symptoms were reported in suspected VRF cases. CBCT was the most commonly requested auxiliary exam. Professional qualification influenced the number of reported signals and symptoms, the number of auxiliary exams, and the clinical management strategies in suspected VRF cases. Key words:Cone Beam Computed Tomography, Endodontics, Questionnaire-based Study, Radicular Fracture, Vertical Root Fracture.

Background: Impacted third molars are common and often require surgical removal, which can lead to postoperative complications, particularly pain. While pain has been extensively studied in specialist settings, data from general dental practice remains limited. This study evaluated postoperative pain over seven days following mandibular third molar surgery performed by general dental practitioners (GDPs), who conduct a significant number of these procedures.

Material and methods: A prospective multi-center cohort study was conducted in three public dental clinics in Luleå, Sweden, from October 2022 to December 2023. Participants (≥18 years old) undergoing mandibular third molar surgery were included, while those requiring referral to an oral maxillofacial surgeon were excluded. Pain intensity was self-reported daily using a numerical rating scale (NRS) from 0-10. Statistical analyses included descriptive statistics, chi-square tests, and t-tests.

Results: Of 133 enrolled participants, 111 submitted valid pain assessments. Pain peaked on the day of surgery (Day 0), with 4% reporting the worst imaginable pain (NRS 10), 34% severe pain (NRS 7-9), and 35% moderate pain (NRS 4-6). Pain significantly declined by Day 1 (p<0.001) and continued to decrease throughout the week. Female participants reported higher pain scores (statistically significant on Days 2-4) and used more analgesics. Sedated patients also reported higher pain scores. Bilateral surgeries showed slightly higher pain levels, though not statistically significant. Postoperative complications were rare (one case of paraesthesia, two infections).

Conclusions: Postoperative pain after third molar surgery performed by GDPs was highest on the day of surgery and declined rapidly. Key words:Postoperative pain, third molar, oral surgery.

Background: To assess the association between tongue posture and transverse dental compensation patterns in teeth of Class III skeletal patients and to compare the above associations between Class III skeletal patients and Class I skeletal patients.

Material and methods: This retrospective study was conducted in the Department of Orthodontics and Dentofacial Orthopedics, Manipal College of Dental Sciences, Mangalore. The records of 126 subjects including skeletal class I subjects as the control group (n = 63) and skeletal class III patients as the experimental group (n = 63) were obtained. The tongue-to-palate distance of all the subjects was measured using the method described by Graber (Graber et al., 1997) on lateral cephalograms. CBCT images were standardized and acquired by keeping the patient's head in the natural position. Buccolingual inclinations were measured on CBCT coronal sections as the angle between the reference plane (line perpendicular to the line joining the buccal and lingual crest of the alveolar bone) and the long axis of each tooth. SPSS software, version 25.0 was used to perform the statistical analyses. To analyze the association between tongue posture and buccolingual inclination of teeth, the Pearson correlation coefficient was calculated, with a power of 80%.

Results: Statistically significant differences were found for skeletal Class III malocclusion. The degree of buccal tipping at 17, 15, 14, 27, 25, 24 and the tongue-to-plate distance at D3 and D4 were significantly correlated, with a p value <0.001. The degree of buccal tipping at 16, 26 and the tongue-to-plate distance at D1, D2, D3, D4 and D5 showed a moderate positive correlation and was significant. In general, a positive correlation was observed between the degree of buccal tipping of maxillary posterior teeth and the tongue posture at D1-D5. A moderate positive correlation was observed between the degree of lingual tipping of molars and premolars and the tongue-to-palate distance at D1, D2, D3, D4 and D5.

Conclusions: Based on the observations of skeletal Class III patients, the following conclusions can be drawn:a) The tongue assumes a lower and more anterior position than does the tongue in Class I subjects.b) The tongue-to-palate distance increases at positions D2-D5, revealing a strong association between tongue forces and buccal flaring of maxillary posterior teeth.c) Lingual tipping of mandibular posterior teeth showed a constant moderate association with tongue position at D1-D5 and was significant, but not as significant as that observed for maxillary posterior teeth. Key words:Tongue posture, buccolingual tooth inclination, skeletal class III, dentoalveolar compensation, soft tissues.

Background: Guided bone regeneration (GBR) requires resorbable implants that balance corrosion resistance and biocompatibility. Magnesium (Mg) is a promising candidate, but its rapid degradation necessitates protective coatings. This study develops and characterizes a strontium-zinc (Sr-Zn) conversion coating on Mg plates for resorbable tack screws, evaluating its corrosion resistance, surface properties, and biocompatibility.

Material and methods: Mg plates (20×15×2 mm) were etched with HCl, coated with Sr-Zn via immersion (30 min, pH 3-5), and characterized using SEM, EDX, and FTIR. Corrosion resistance was assessed via potentiodynamic polarization in simulated body fluid (SBF). Biocompatibility was evaluated using MG63 osteoblast cultures, with statistical comparison (Student's t-test, p < 0.05) between coated (Group A) and uncoated (Group B) plates.

Results: SEM revealed a dense, fibrous coating with interconnected pores, enhancing cell adhesion. EDX confirmed Zn (46.6 wt%) and Sr (3.7 wt%) incorporation. FTIR identified hydroxyl/carbonyl groups and metal-oxygen bonds. The coating improved corrosion resistance compared to bare Mg plates. In vitro cell culture assays demonstrated that Sr-Zn conversion-coated Mg plates (Group A) showed comparable cell viability to bare Mg plates (Group B) at all tested time points. Peak cell viability was recorded at 24 hours, with Group A achieving 92.66% and Group B reaching 91% (p = 0.238). This statistically non-significant difference suggests successful biocompatibility of the Sr-Zn coating. The enhanced biocompatibility observed is likely attributed to the coating's improved corrosion resistance.

Conclusions: The Sr-Zn coating improved Mg's corrosion resistance while maintaining osteoblast viability, supporting its potential for resorbable GBR tack screws. Key words:Guided bone regeneration, Magnesium implants, Strontium-zinc coating, Corrosion resistance, Biocompatibility, Resorbable screws.

Background: Proper finishing and polishing are crucial for reducing surface roughness and eliminating the incompletely polymerized oxygen-inhibited layer. This study compared surface characteristics - specifically water contact angle, surface roughness, and morphology of three nanohybrid composite resins polished with two different multi-step polishing systems.

Material and methods: We evaluated Filtek Z250 (3M), Tetric N-Ceram (Ivoclar), and Spectra Smart (Dentsply), all in shade A2. Thirty-nine discs per resin (9 mm diameter × 2 mm thickness) were fabricated, stored in distilled water at 37°C for 24 hours, and pre-polished with silicon carbide paper (600, 1000, and 1200 grit). Final polishing employed two systems: the 3-step Astropol system (Ivoclar) and the 2-step ShapeGuard system (Diatech), with each system tested through six reuse cycles (three samples per resin per cycle). Surface analysis included water contact angle measurement, profilometry, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS).

Results: The Astropol system demonstrated significantly greater hydrophobicity (107.6° ± 10.9°) than ShapeGuard (99.1° ± 9.0°). Among the tested resins, Filtek Z250 polished with Astropol showed the lowest surface roughness (0.27 ± 0.11 µm), while Spectra Smart polished with ShapeGuard showed the highest (0.78 ± 0.20 µm). Polishing system reuse showed no significant effects on results. SEM revealed no noTable morphological changes, and EDS confirmed consistently high SiO2 content across all resins.

Conclusions: Both polishing system and resin composition significantly influence surface characteristics. Filtek Z250 performed optimally with both polishing systems. Further research should investigate the long-term effects of polishing system reuse. Key words:Nanohybrid resins, polishing systems, surface roughness, contact angle, SEM.