Myasthenia gravis is an autoimmune neuromuscular disorder characterized by fluctuating weakness and skeletal muscle fatigue. Clinical signs and symptoms may vary considerably according to the age at presentation, patterns of autoantibodies and associated thymic abnormalities, so that therapeutic options are highly individualized. Facial and oropharyngeal muscle weakness is common at disease onset, and therefore dentists are often the first health professionals to encounter these patients. Myasthenic patients require special consideration and advice in order to ensure optimal and safe dental treatment. Oral manifestations, treatment timing and modality, the choice and effects of drugs and medications, and prevention of myasthenic crisis are all important aspects with which dentists and oral health care providers should be thoroughly acquainted. (J Oral Sci 57, 161-168, 2015)

抄録全体を表示

About 20% of the world’s population uses some form of betel nut, which suggests that the incidence of oral submucous fibrosis (OSF) is higher than current estimates. OSF has the potential to undergo malignant transformation; thus, there is a need to identify relevant markers to assess its aggressiveness. We evaluated changes in COX-2, p53, and MDM2 expressions in progressive OSF. Expressions of COX-2, p53, and MDM2 increased with OSF progression. There was a strong association between COX-2 overexpression and recurrence of oral squamous cell carcinoma (P < 0.001) and a positive relation between increased MDM2 expression and failure of radiotherapy (P = 0.007). These findings suggest that COX-2 is an important marker of disease progression and that MDM2 expression is useful for treatment planning. (J Oral Sci 57, 169-176, 2015)

抄録全体を表示

We investigated inhibition of lesion progression in artificial enamel lesions. Lesions were created on primary and permanent anterior teeth (n = 10 each) and were divided randomly into two groups with two windows: Group 1 (window A: resin infiltration; window B: negative control) and Group 2 (window A: resin infiltration + fluoride varnish; window B: fluoride varnish). After pH cycling, micro-computed tomography was used to analyze progression of lesion depth and changes in mineral density. Resin infiltration and resin infiltration + fluoride varnish significantly inhibited progression of lesion depth in primary teeth (P < 0.05). Inhibition of lesion depth progression in permanent teeth was significantly greater after treatment with resin infiltration + fluoride varnish than in the negative control (P < 0.05). Change in mineral density was smaller in the resin infiltration and resin infiltration + fluoride varnish groups; however, the difference was not significant for either group (P > 0.05). Resin infiltration is a promising method of inhibiting progression of caries lesions. (J Oral Sci 57, 177-183, 2015)

抄録全体を表示

This study evaluated the retention characteristics of ProRoot mineral trioxide aggregate (MTA), RetroMTA, Supra MTA, and Biodentine biomaterials used to repair furcation perforations contaminated with blood. Furcal perforations measuring 1.3 mm in diameter and 2 mm in height were created in 96 mandibular first molar teeth, which were then randomly divided into the following two groups (n = 48): contaminated (+) or non-contaminated (–) with blood. The groups were subdivided into four groups (n = 12) according to the material used (ProRoot MTA, RetroMTA, Supra MTA, and Biodentine) to seal the perforations. The samples were allowed to set for 14 days and were then subjected to push-out testing. The results were analyzed using ANOVA, and the failure modes were examined using a surgical microscope. ProRoot MTA (+/−) and RetroMTA (+/−) exhibited superior bond strength values; in addition, there were no significant differences among these groups (P > 0.05). Biodentine (+) showed intermediate values that were sometimes statistically similar to the ProRoot MTA (+/−) and RetroMTA (+/−) groups (P > 0.05) and, at other times, the Biodentine (−) and Supra MTA (+/−) groups (P > 0.05). The lowest bond strength values were shown by the Biodentine (−) and Supra MTA groups (P > 0.05). “Adhesive failure mode” was the most frequently observed type for all tested materials. Blood contamination did not affect the dislocation resistance of materials. (J Oral Sci 57, 185-190, 2015)

抄録全体を表示

Traumatic dental and facial injuries are frequent in sports and often cause esthetic, functional, psychological, and economic problems. The term “weekend warrior” is used to describe people who participate in physically demanding activities only on the weekend, or part-time. In this prospective cohort study, we examined the prevalence of dental trauma and knowledge of traumatic dental injuries among weekend warriors in Ankara, Turkey. A detailed questionnaire on mouthguard awareness and knowledge and experience of dental trauma was distributed to 1,007 weekend warrior athletes participating in a soccer tournament. The results showed that 9.8% of participants had experienced orofacial trauma, 21.7% were aware of mouthguards, 2.9% reported using mouthguards, 15.4% were aware of the field of sports dentistry, and 19.6% were aware of emergency treatment for dental trauma. Participation in sports, especially contact sports, greatly increases the risk of dental injury. The present results show that knowledge of traumatic orofacial and dental injuries is limited among weekend warriors. Public health authorities should develop relevant educational programs, including broad dissemination of information on the risks of traumatic dental injuries and methods for protection against such injuries. (J Oral Sci 57, 191-194, 2015)

抄録全体を表示

Volumetric changes of the alveolar ridge after socket preservation with various techniques have been investigated frequently. However, changes in bone density and quality of bone within the extraction sockets have seldom been studied. The purpose of this study was to evaluate the bone quality of grafted versus non-grafted socket sites prior to dental implant placement using Hounsfield unit (HU) values derived from cone-beam computed tomography (CBCT) imaging. The data was collected from 39 healed extraction sites reviewed over a one-year period. Subjects eligible for the study had a bone replacement graft and barrier membrane. Both study and control groups had CBCT scans performed immediately after extraction and four to five months after extraction for planning implant placement. HU values were measured from the CBCT scans and compared between groups. Intragroup variability was assessed utilizing standard deviation and standard error of the mean. Intergroup differences were evaluated using unpaired t-test. A generalized lack of significant difference in bone quality was observed between groups with the only statistically significant difference observed in the posterior maxilla. Future radiographic and histologic assessments of bone quality after socket preservation are required to determine the ‘ideal’ approach to preserve an extraction socket prior to implant placement. (J Oral Sci 57, 195-200, 2015)

抄録全体を表示

We evaluated the effects of nonsurgical periodontal therapy in 100 patients with type 2 diabetes and chronic periodontitis. The participants were classified as having good (n = 48) or poor (n = 52) glycemic control and were further randomly allocated to receive either scaling and root planning treatment group or no treatment (n = 50 each). The effect of nonsurgical periodontal therapy was compared among diabetic patients with good glycemic control, those with poor glycemic control, and 25 nondiabetic individuals. Periodontal and metabolic status was recorded at baseline, 3 months, and 6 months. In patients receiving treatment, periodontal parameters significantly improved and HbA_1c decreased by 10.8%. Improvements in gingival index and bleeding on probing were greater in the nondiabetic participants and the treated patients with good glycemic control than in the treated patients with poor glycemic control (P < 0.05). Regression analysis showed that improvement in periodontal status was independently associated with glycemic improvement. Nonsurgical periodontal therapy improved glycemic control and periodontal health in patients with type 2 diabetes. However, patients with poor baseline glycemic control had less clinical improvement than did those without diabetes and those with good glycemic control. (J Oral Sci 57, 201-211, 2015)

抄録全体を表示

We explored longitudinally the inhibitory effect of gels loaded with 1 mg/mL modified triple antibiotic paste (MTAP) or double antibiotic paste (DAP) against biofilm formation by Enterococcus faecalis and Porphyromonas gingivalis. Methylcellulose-based antibiotic gels of MTAP (ciprofloxacin, metronidazole and clindamycin) and DAP (ciprofloxacin and metronidazole) were prepared at a concentration of 1 mg/mL. Individually cultured E. faecalis and P. gingivalis bacterial suspensions were treated with MTAP, DAP, or placebo (vehicle only) gels at different dilutions and allowed to grow in 96-well microtiter plates. Untreated bacterial suspensions served as a negative control. Crystal violet assays were used to evaluate biofilm formation after 48 h. The ability of the gels to inhibit biofilm formation was determined immediately, and at 1 month and 3 months after the gels had been prepared. Data were analyzed using a mixed-model ANOVA. The MTAP and DAP gels significantly reduced biofilm formation by both bacterial species at all time points, regardless of the tested dilution. No-significant differences in biofilm-inhibitory effects between MTAP and DAP gels were observed at the majority of the tested dilutions through various time points. Gels loaded with 1 mg/mL MTAP and DAP demonstrated a significant antibiofilm effect against E.faecalis and P. gingivalis. (J Oral Sci 57, 213-218, 2015)

抄録全体を表示

The aim of this study was to evaluate the effects of the remnants of two suture materials on osseointegration of titanium implants in a rabbit tibial model. Calibrated defects were prepared in the tibia of five Chinchilla rabbits. Filaments of nonresorbable (NR) nylon or resorbable (R) chitosan were placed at the bone to implant interface, whereas control sites had no suture material. After a healing period of 4 weeks, a pull-out test procedure was performed followed by enzymatic analyses of the wound fluid and relative quantification of mRNA levels for bone-related and cytokine markers from the peri-implant bone. A trend toward a reduced pull-out force was observed in the NR group (NR: 23.0 ± 12.8 N; R: 33.9 ± 11.3 N; control: 33.6 ± 24.0 N). Similarly, the bone resorption marker vacuolar type H+-ATPase was increased in the NR group compared with that in the control group (P = 0.041). The R group showed trends for lower alkaline phosphatase activity and osteocalcin expression and higher total protein content and RNA compared with the control group. In this submerged healing model, peri-implant bone healing was marginally affected by the two suture materials tested. However, there was a tendency toward better osseointegration and lower expression of bone resorption markers in the R group compared with the control group. (J Oral Sci 57, 219-227, 2015)

抄録全体を表示

The aim of this study was to evaluate the effects of UVA-activated riboflavin (UVA-RF) on the mechanical properties of non-demineralized human dentin. Dentin specimens obtained from 20 teeth were randomly divided into the following four groups: group 1 (control): no treatment, group 2 (low UVA-RF): specimens were exposed to UVA-RF for 10 min, group 3 (medium UVA-RF): specimens were exposed to UVA-RF for 30 min, and group 4 (high UVA-RF): specimens were exposed to UVA-RF for 60 min. Three-point flexural test and Raman spectroscopic analyses were performed. The mean flexural strengths (MPa) were 129.96, 128.96, 144.21, and 147.54, and the mean elastic modulus (GPa) were 8.59, 8.38, 10.21, and 9.87 for groups 1 to 4, respectively. Raman spectra showed chemical modifications of dental collagen under medium and high UVA-RF treatment. We conclude that medium and high UVA-RF increases the strength of non-demineralized human dentin by collagen crosslinking. (J Oral Sci 57, 229-234, 2015)

抄録全体を表示

As part of quality assessment of a teleradiology program we evaluated the validity of patient information received, the quality of panoramic radiography imaging in Laos, and the ability of a Laotian radiologist to detect temporomandibular joint abnormalities. The amount of patient information gathered from 2,021 scans of panoramic radiographs was evaluated by triage before image diagnosis. Among the radiographs from 2,021 patients, primary triage indicated that there was insufficient information for 794 (39.3%) patients. Secondary triage to assess imaging failure included 1,227 radiographs, four of which were excluded from imaging diagnosis because of unacceptable image flaws. In total, 2,446 joints from 1,223 radiographs were evaluated for temporomandibular joint abnormalities in order to compare the image interpretation abilities of Laotian and Japanese radiologists. The kappa coefficient was 0.836 (P < 0.01) for the agreement between the two observers in detecting temporomandibular joint abnormalities on radiographs. We conclude that additional efforts are needed in order to overcome the challenges of maintaining quality in imaging techniques and diagnoses in Laos. (J Oral Sci 57, 235-239, 2015)

抄録全体を表示

We investigated the outcome of conventional periodontal treatment in mouth breathing patients with chronic periodontitis, and compared the efficacy of applying salivary substitute to the anterior sextants as an adjunct to conventional treatment in such patients. In this randomized, investigator-blind, clinical study involving parallel groups, 40 mouth breathing patients were divided into two groups: a control group (CG, n = 20) comprising patients who received scaling and root planing (SRP), and a test group (TG, n = 20) who received salivary substitute as an adjunct to SRP for treatment of chronic periodontitis. The patients were followed up at various time intervals, and improvement of the gingival index (GI) was examined as the primary outcome. Student’s t-test, repeated-measures ANOVA and Mann-Whitney U test were applied for statistical analysis. Although periodontal parameters were improved in both groups after 8 weeks of follow-up, the test group showed better improvement in terms of GI and percentage bleeding on probing. Within the limits of this study, our results suggest that the use of salivary substitute has a beneficial adjunctive effect for improvement of periodontal parameters in mouth breathing patients with chronic periodontitis. (J Oral Sci 57, 241-247, 2015)

抄録全体を表示

Compliance with supportive periodontal therapy (SPT) depends on many factors but is generally poor. We compared SPT compliance among patients with aggressive and chronic periodontitis. This single-center longitudinal observational study enrolled 101 patients with generalized aggressive periodontitis (GAP; n = 52) or generalized chronic periodontitis (GCP; n = 49) to compare SPT compliance. All participants were studied for 1 year before the close of data collection. Compliance was classified as complete (100% of programmed visits), erratic (≥50% of programmed visits), or noncompliant (<50% of programmed visits). The proportion of compliant participants was greater among patients with GAP (57.7%) than among those with GCP (30.6%) (P < 0.003); 44.9% of patients with GCP and 15.4% of those with GAP were noncompliant. Compliance was significantly associated with age and sex among patients with GAP. In conclusion, SPT compliance was better in patients with GAP than in those with GCP. Patient attitude and self-belief appear to be important factors in SPT compliance. (J Oral Sci 57, 249-254, 2015)

抄録全体を表示

The objective of this study was to evaluate fracture strength of high-translucent (HTZ) and low-translucent (LTZ) zirconia and glass-ceramic (LDS) crowns. HTZ and LTZ crowns were made with thicknesses of; 0.3 mm, 0.5 mm, 0.7 mm, 1.0 mm, and 1.5 mm; and LDS crowns of 1.0 mm and 1.5 mm thicknesses. Each group consisted of 10 crowns. All crowns underwent artificial aging before loading until fracture. Mean fracture strengths varied from 450 N to 3,248 N in the LTZ group, 438 N to 3,487 N in the HTZ group, and 1,030 N to 1,431 N in the LDS group. The load at fracture of HTZ and LTZ crowns was equal. The load at fracture of yttria-stabilized tetragonal zirconia polycrystals crowns was significantly greater than LDS crowns (P = 0.000). Two types of fractures were recorded; complete and partial crack-like fracture. The crack type fracture occurred most frequently in all groups except in the thicker LTZ groups (1.0 mm and 1.5 mm). According to this study, there is no difference in strength between crowns made of high-translucent or low-translucent zirconia. At equal thickness, the strength of zirconia crowns was significantly greater than that of lithium-disilicate glass-ceramic. (J Oral Sci 57, 255-261, 2015)

抄録全体を表示

Orofacial trauma can occur during general anesthesia. Protective measures should be taken to prevent or minimize such injuries. We evaluated perceptions regarding the occurrence and prevention of orofacial injuries during general anesthesia among 74 professionals who perform this procedure. All participants were from Rio de Janeiro, Brazil, and information was collected in interviews, using a semi-structured questionnaire administered during an academic conference. The data were tabulated and analyzed, frequencies were calculated, and the chi-square test (P < 0.05) was used to assess relationships between variables of interest. Most participants (77.0%) had witnessed orofacial trauma during general anesthesia, and the most frequent type of dental injury was fracture (54.4%). Although most participants (64.9%) considered mouthguard use to be important during such procedures, only three reported using mouthguards to protect against patient injury. The likelihood of a dentist referral after injury was significantly associated with participant age (P = 0.03), length of time since graduation (P = 0.02), and area of specialization (P ≤ 0.01). Although most participants had witnessed orofacial injuries, mouthguards were not routinely used for injury prevention. (J Oral Sci 57, 263-267, 2015)

抄録全体を表示

A 47-year-old man was referred for assessment of bilateral lymph node enlargement identified on a routine chest radiograph. Positron emission tomography showed high standardized uptake values (SUVmax: 20.5) in right supraclavicular, right intercostal, and multiple mediastinal lymph nodes. Biopsy samples obtained from the right upper and left lower paratracheal nodes by mediastinoscopy revealed granulomatous inflammation. Clinical and laboratory findings indicated a diagnosis of dental technician pneumoconiosis. The patient is alive and well 3 years after diagnosis. This case highlights the importance of obtaining an occupational history. (J Oral Sci 57, 269-271, 2015)

抄録全体を表示

Although autogenous tooth transplantation is a widely reported procedure, its success is dependent on a number of factors. Here we describe the surgical technique, endodontic treatment and rehabilitation employed for a patient in whom a lower right third molar was transplanted to substitute an adjacent second molar with extensive caries. During an 8-year follow-up period, normal periodontal healing was observed and no infection, ankylosis or progressive resorption occurred. It may be concluded that transplantation of a third molar is a practicable approach for replacement of a lost permanent tooth, with restoration of esthetics and function. (J Oral Sci 57, 273-276, 2015)

抄録全体を表示