Journal of oral science最新文献

Purpose: To assess the sensitivity and the effect of topical lidocaine on the tongue by quantitative sensory testing, comparing healthy middle-aged female subjects with healthy young female subjects.

Methods: Sixteen healthy female subjects including eight in their fifties and eight in their twenties participated. They participated in two sessions at a 2-week interval in randomized order: lidocaine (experimental session) or placebo gel (placebo session) was applied on the tongue tip for 5min. The following parameters were taken on the tongue tip before and after application of the gel in each session: tactile detection threshold (TDT), filament-prick pain detection threshold (FPT), and numerical rating scale (NRS).

Results: An increase of both TDT and FPT and a decrease of NRS were found after lidocaine application in both middle-aged and young female subjects. In the elder females, an increase of TDT, FPT, and NRS was also found after placebo gel application. However, the changes were not statistically significant, except for FPT in middle-aged subjects.

Conclusion: The reactions found after lidocaine application in middle-aged female subjects could be due to habituation as well as to the post-application effect of placebo gel. Placebo-induced changes appeared more pronounced in the elder females.

Purpose: The aim of this study was to measure residual monomer, cell adhesion, and cell viability of 3-dimensional printable permanent resin (PR), hybrid ceramic block (HCB), and indirect composite (IC) produced with additive, subtractive, and conventional techniques.

Methods: Five 8 × 8 × 2 mm³ samples of each material were prepared for each experiment. In a 24-h period, monomer release was analyzed with high-performance liquid chromatography, and cell viability and adhesion were evaluated with the water-soluble tetrazolium salt test. Data were analyzed with IBM SPSS Statistics 26.0 statistical software, and results were regarded as significant at α = 0.05.

Results: Monomer release (triethylene glycol dimethacrylate, urethane dimethacrylate, and Bisphenol A glycerolate dimethacrylate) was significantly higher in the IC group. Mean cell viability was significantly lower in the HCB group than in the IC group.

Conclusion: All monomers in the tested materials were released at rates that were below clinical significance. Cell adhesion rates in the groups were similar. Cytotoxic response was classified as minor in the HCB and PR groups and non-cytotoxic in the IC group.

Purpose: This study investigated the efficacy of various antiseptics for disinfection of rubber dams used during endodontic treatment, the duration of disinfection effectiveness, and the disinfection protocol employed by dental schools in Thailand.

Methods: The efficacy of 10% povidone-iodine, 1.5% tincture iodine and 70% ethyl alcohol in eliminating Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans) on the rubber dam was investigated. Time duration of disinfection was evaluated at 0, 30, 60, and 120 min. The two-step disinfection method adopted at Thai dental school was examined. Independent t-test or Kruskal-Wallis followed by a Dunnett's test was used for statistical analysis.

Results: Among the three antiseptics, 10% povidone and 1.5% tincture iodine eradicated the microorganisms completely, whereas 70% ethyl alcohol did not achieve a statistically significant decrease. The duration of sterilization effectiveness was 120 min for 10% povidone-iodine, but bacteria were eliminated only at 0 min by 1.5% tincture iodine. The results also indicated that the two-step protocol scarcely eliminated the microorganisms.

Conclusion: The best antiseptic for rubber dam disinfection is 10% povidone-iodine, which remains effective for 120 min. The two-step protocol typically practiced in Thai dental schools needs to be updated. The use of 10% povidone-iodine alone is adequate for complete eradication of E. faecalis and C. albicans.

Various neuropathies of the cranil nerves can accompany trigeminal neuropathic pain attributed to space-occupying lesions. In this case report, the patient presented with persistent intraoral pain and numbness on the right side of the face. Cranial nerve examination revealed dysfunctional eye movements, diplopia, and mechanical hyposensitivity in the mandibular region. The patient was diagnosed with neuropathy due to intracranial lesions and referred to the Department of Neurosurgery and Otorhinolaryngology. The patient was suspected of having malignant lymphoma and is currently undergoing neurosurgical intervention. This article discusses the importance of the examination of the cranial nerve for patients with persistent pain in the trigeminal nerve distribution.

Purpose: After tooth extraction, preservation of the alveolar ridge by socket grafting attenuates bone resorption. Runt-related transcription factor 2 (RUNX2) and SP7/Osterix (OSX) are transcription factors playing an important role in osteoblast differentiation. The purpose of this study was to evaluate the effects of carbonate apatite (CO₃Ap) on osteoblast-related gene and protein expression after socket grafting.

Methods: Alveolar bone and new bone after CO₃Ap grafting were collected at the time of implant placement. Levels of mRNA for RUNX2, SP7/OSX, bone morphogenetic protein 2 (BMP2), BMP7 and platelet derived growth factor B were determined by real-time PCR. Immunostaining was performed using antibodies against RUNX2, SP7/OSX, vimentin and cytokeratin. To evaluate bone resorption rates, cone-beam CT (CBCT) imaging was performed after socket grafting and before implant placement.

Results: CBCT imaging showed that the average degree of bone resorption at the CO₃Ap graft site was 7.15 ± 3.79%. At the graft sites, levels of SP7/OSX and BMP2 mRNA were significantly increased. Replacement of CO₃Ap with osteoid was evident histologically, and in the osteoid osteoblast-like cells were stained for SP7/OSX and vimentin.

Conclusion: These results show that gene expression of both SP7/OSX and BMP2 can be induced by CO₃Ap, suggesting that increased expression of SP7/OSX and vimentin may be involved in the BMP pathway.

Purpose: To evaluate the image quality of vertical dual-exposure panoramic radiography (PR), which merges two PR images taken at different focus heights to reduce ghost images of cervical vertebrae (CV) and intervertebral spaces (IVS) in the incisor region.

Methods: PR images of an aluminum block, a CV phantom and a human head phantom were taken at 0 mm and merged with and subtracted from PR images taken at other heights (0, 5, 10, 15, and 20 mm) to create new images, e.g., Merg_{0 + 15 mm} and Sub_{0 - 10 mm}. The subtracted images were analyzed subjectively according to the uniformity on the line profile. Merged images were evaluated subjectively by six raters to determine the influence of the ghost images.

Results: Objective evaluation revealed a positional shift in the ghost images according to the height of the focus for both phantoms. In the subjective evaluation, the normal PR (Merg_{0 + 0 mm}) showed the worst score, indicating strong influence of CV and IVS ghost images.

Conclusion: The vertical dual-exposure PR method, which merges PR images taken at the normal position and a higher X-ray focus, can reduce CV and IVS ghost images in the incisor region.

Purpose: To evaluate the accuracy of osteotomy preparation and implant placement for 3 pilot-guided (PG) concepts, namely, a surgical template with a metal sleeve (MS), a surgical template with an in-built nonmetal sleeve (NMS), and a surgical template with an in-built nonmetal sleeve for round bur indentation (RB).

Methods: Surgical models with missing maxillary molars were studied. The MS templates were designed to accept metal sleeves, while the NMS and RB templates were designed with in-built nonmetal sleeves. Ten templates were tested per group (n = 10). After each step (pilot drilling, 2nd drilling, 3rd drilling, profiling, and implant placement), the surgical model was scanned and compared against the planning model to determine maximum horizontal deviation (MHD) and maximum angle deviation (MAD).

Results: The MS and NMS templates exhibited a similar increase in MHD with successive drilling steps. The MAD for the pilot drilling step was significantly lower for MS than for the other groups. However, the differences among groups for MHD and MAD diminished in later steps. All templates had an MHD of 1.0 mm or less and an MAD less than 8°.

Conclusion: The investigated PG implant placement concepts resulted in similar deviations in the placed implants.

The oral cavity is the starting point and an integral part of the respiratory system. Oral bacteria are deeply involved in the onset and aggravation of lower respiratory tract diseases, including aspiration pneumonia, influenza, and chronic obstructive pulmonary disease. Oral health conditions, such as periodontal disease, influence the severity of coronavirus disease 2019 (COVID-19). Oral bacteria can be detected in the respiratory organs of patients with COVID-19, and the composition of oral bacterial flora may be altered. Aspiration pneumonia is common among patients with COVID-19 who are advanced in age or have underlying diseases due to poor oral hygiene management, fever, and other issues. While findings from further studies are awaited, maintaining a healthy oral cavity can prevent COVID-19 onset and aggravation. In addition to routine management of oral microflora at home and maintenance of periodontal health in dentistry, medical-dental collaboration is crucial for a prompt response to future pandemics, as humans have just experienced in COVID-19.

Purpose: To evaluate the influence of the polymerization distance of monowave and polywave light curing units (LCUs) on the measured irradiance relative to the value reported by the manufacturer in relation to the physical properties of resin-based composites (RBCs).

Methods: Four LCUs were used: one monowave and three polywave. The irradiance was measured with a digital radiometer. Depth of cure (DC) and flexural strength (FS) tests were performed according to ISO 4049:2019 at polymerization distances of 0 mm and 5 mm.

Results: The irradiance of all LCUs was higher than that reported by the manufacturer (>25-64%). The irradiance of the four LCUs was reduced when polymerization was performed at between 0 to 5 mm (paired t-test, P < 0.001). The DC at 0 mm was similar in all groups but was significantly decreased at 5 mm distance (ANOVA P < 0.001). FS showed differences among the LCUs at 0 mm (ANOVA P < 0.001) and was affected by the polymerization distance. The elastic modulus was unaffected by the LCU used or the distance (ANOVA P > 0.001).

Conclusions: The LCU must be positioned as near as possible to RBCs during the polymerization process, as increased distance negatively affects the depth of cure and flexural strength.

Purpose: To investigate the influence of various nickel-titanium (Ni-Ti) files on debris extrusion during the retreatment of teeth with simulated lateral root perforation, focusing on root resorption.

Methods: Sixty human mandibular premolar teeth were divided into groups with and without perforation and further subdivided based on the retreatment technique. Lateral root perforations were created in one group (Group 1), while the other group had no perforations (Group 2). Two retreatment techniques were compared: Remover (RE)+One RECI (OR) and ProTaper Universal Retreatment (PTUR)+WaveOne Gold (WOG). The weight of the extruded debris was determined. The time of both retreatment procedures was measured. Statistical analyses were performed using a two-way analysis of variance (ANOVA) test (P < 0.05).

Results: Teeth with simulated lateral root perforation exhibited higher extrusion of debris during retreatment. In both groups, RE+OR files led to more extruded debris than PTUR+WOG files. However, this difference was statistically significant in Group 2 (P < 0.001). Compared to PTUR+WOG files, RE+OR files showed a statistically significant longer time to remove obturation material (P < 0.001).

Conclusion: Perforated teeth exhibited significantly higher debris extrusion. While both file systems demonstrated similar debris extrusion in perforated teeth, the RE+OR files significantly increased debris extrusion in non-perforated teeth compared to the PTUR+WOG files.