Direct pulp capping helps extend the life of a diseased tooth by maintaining tooth vitality. Nowadays, lasers are more frequently used during direct pulp capping in the clinic, but their use has not been previously reviewed. This review presents the basic properties of currently available lasers, scientific evidence on the effects of laser application on direct pulp capping, and future directions for this technology. An extensive literature search was conducted in various databases for articles published up to January 2015. Original in vitro, in vivo, and clinical studies, reviews, and book chapters published in English were included. Various laser systems have been increasingly and successfully applied in direct pulp capping. Lasers offer excellent characteristics in terms of hemostasis and decontamination for field preparation during direct pulp capping treatment; however, the sealing of exposed pulp with one of the dental materials, such as calcium hydroxide, mineral trioxide aggregates, and bonded composite resins, is still required after laser treatment. Clinicians should consider the characteristics of each wavelength, the emission mode, irradiation exposure time, power, type of laser tip, and the distance between the laser tip and the surface being irradiated. (J Oral Sci 57, 277-286, 2015)

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Dermoid cysts (DMCs) and epidermoid cysts (EDMCs) usually arise in soft tissues, whereas orthokeratinized odontogenic cysts (OOCs) and keratocystic odontogenic tumors (KCOTs) develop in the jaw. In this study, we performed immunohistochemical analysis of cytokeratins (CKs) to examine differences in the lining epithelium of DMCs, EDMCs, OOCs, and KCOTs. In addition, we carried out immunohistochemical examination of langerin to clarify the biological characteristics of the orthokeratinized lining epithelium of DMCs, EDMCs, and OOCs. Seven DMCs, 30 EDMCs, 11 OOCs, and 28 KCOTs were examined immunohistochemically using antibodies against CK10, 13, 14, 16, 17, 19, and langerin. Immunoreactivities for CKs and langerin in oral DMCs and EDMCs were similar to those of lesions affecting the skin. Positive reactivity for CK13 and 17 was evident in OOCs, but not in DMCs/EDMCs. CK10 was significantly positive in all layers except for the basal layer in OOCs, but was negative in KCOTs. CK17 was positive in all layers in KCOTs, and in all layers except for the basal layer in both OOCs and dentigerous cysts. CK19 was negative in OOCs. Langerhans cells were found mainly in OOCs, but were hardly evident in KCOTs. These results suggest that DMCs/EDMCs, OOCs and KCOTs are independent diseases. (J Oral Sci 57, 287-294, 2015)

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Chronic inflammation is considered to be one of the risk factors for carcinogenesis. It was recently reported that telomerase plays an important role in inducing such chronic inflammation. Although high telomerase activity is detected in cancer tissues, the activator of telomerase is still unknown. In this study, we used an immunohistochemical method to examine the expression of human telomerase reverse transcriptase (hTERT) in the dysplasia-carcinoma sequence in the oral cavity. Furthermore, the effects of inflammatory cytokines on the telomerase activity and migration of oral cancer cell lines (Ca9-22, HSC-3, and HSC-4) were examined. Immunoreactivity for hTERT was observed in squamous intraepithelial neoplasia 3 and squamous cell carcinoma. Telomerase activity in Ca9-22 cells was increased by treatment with TNF-α and INF-γ, while its activity in HSC-4 cells was decreased by IL-1β. Although inflammatory cytokines did not affect the proliferative activity of any of the oral cancer cell lines, cytokines and hTERT siRNA promoted the migration of HSC-3 cells. These results suggest that the presence of long-term chronic inflammation may increase telomerase activity and therefore contribute to malignant transformation of the oral mucosal epithelium. Furthermore, inhibition of telomerase activity by inflammatory stimuli increases the invasion of certain types of oral squamous cell carcinomas. (J Oral Sci 57, 295-303, 2015)

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Ionomycin is a calcium ionophore that induces release of calcium ions (Ca²⁺) from cellular storage to cytoplasm and Ca²⁺ influx from the outside of the cell. We investigated the effect of ionomycin on endoplasmic reticulum (ER)-Golgi transport in the vesicular stomatitis virus glycoprotein (VSV-G) system. Ionomycin inhibited transport of VSV-G in a concentration-dependent manner in baby hamster kidney (BHK) cells and HeLa cells. Half-maximum inhibition was observed at 5 μM. The inhibitory effect of ionomycin was not dependent on the cytoplasmic portion. Chelation of Ca²⁺ in culture medium did not affect transport efficiency, but co-incubation with ionomycin completely shut off transport. These findings highlight the importance of Ca²⁺ release from cellular storage. Because the inhibitory effect of ionomycin was expected to be dependent on mutual interaction of VSV-G and the ER chaperone calnexin, we further investigated interaction kinetics. In HeLa cells but not BHK cells the interaction of VSV-G and calnexin was prolonged in the presence of ionomycin. Taken together, the present results indicate that, by releasing Ca²⁺ from cellular storage, ionomycin inhibits ER-Golgi transport by interfering with the release of VSV-G from calnexin in HeLa cells. A mechanism of cell type-dependent ER-Golgi transport regulation was revealed. (J Oral Sci 57, 305-312, 2015)

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We examined the role of Tie2 in regulating wound healing after tooth extraction. Wistar rats underwent maxillary incisor tooth extraction, and immunodetection techniques were used to determine Tie2 expression in the healing wound. The wound was initially filled with blood coagulum containing densely aggregated erythrocytes, leukocytes, fibrin, and endothelial progenitor cells, indicating that blood vessel formation started in the socket. Tie2 was detected on monocytic cell membranes. On day 3, fibroblastic cells proliferated in the coagulum, small vessels appeared by day 5, and new bone formed in the vessel-rich area. Robust woven bone trabeculae were present around vessels by day 7, and woven bone and osteoclast-like giant cells were present on day 10. Woven bone surrounded sinusoidal capillary-like vessels. Full-length (140-160 kDa) Tie2 was not detected at any time, although Tie2 fragments were present in the healing wound. N-terminus- and C-terminus-specific Tie2 antibodies detected 40-kDa and 60-kDa fragments or 70-kDa and 50-kDa fragments, respectively. The levels of these fragments decreased during the first 3 days and started to increase by day 5-10. The Tie2 extracellular domain initially inhibited angiogenesis, and its degradation relieved inhibition of new vessel formation. The onset of vessel formation in the wound may be induced by scattered endothelial progenitor cells. (J Oral Sci 57, 313-318, 2015)

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Determining the molecular mechanisms involved in the healing of wounds created by tooth extraction will likely increase understanding of jawbone healing after dental surgery. Runt-related transcription factor 2 (RUNX2) is required for mesenchymal stem cells to differentiate to osteoprogenitor cells. Therefore, we used a rat model to analyze RUNX2 expression during wound-socket healing after tooth extraction. Immunohistochemical analyses of wound tissue immediately after tooth extraction revealed RUNX2 expression in monocytic cells in the coagulum and, to a lesser extent, in remnants of the periodontal ligament. Shortly thereafter, fibroblastic cells proliferated in the coagulum and large polymorphic cells were enclosed within the newly formed bone matrix. Western blot analysis showed that RUNX2 expression peaked from 12 h to 1 day after extraction and then rapidly declined. These findings indicate that the osteogenic commitment of cells derived from hematopoietic tissue in the extraction wound was greater than that of cells in remnants of the periodontal ligament. Thus, cells derived mainly from hematopoietic tissue and RUNX2 expression are essential in the differentiation of mesenchymal stem cells to osteoprogenitor cells immediately after tooth extraction. (J Oral Sci 57, 319-325, 2015)

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The objective of the present study was to assess the current situation of oral squamous cell carcinoma (OSCC) in northern Thailand, with an emphasis on patients <40 years of age. Medical records of patients histologically diagnosed with OSCC were collected from the Cancer Registry of Maharaj Nakorn Chiang Mai Hospital, Thailand between 2001 and 2010. The clinico-demographic data of patients aged <40 years (young group) and those aged ≥40 years (old group) were compared. A total of 874 patients were included in this study, of which 4.1% were <40 years of age. The tongue was the most common cancer site in both age groups. Most patients in both age groups were diagnosed with oral cancer at stage IV. Tobacco smoking (62.3%) and alcohol consumption (52.3%) were the most common risk factors in both age groups. However, the rates of betel quid chewing (17.5%) had decreased from those found in our study in the previous decade (50.2%); these rates were not found in the young group. The 5-year survival rate was 27.4% for the old group and 56.2% for the young group. OSCC remains a serious oral health problem in northern Thailand, and it has not been resolved among young adults. (J Oral Sci 57, 327-334, 2015)

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Although an association between periodontal status and liver abnormalities has been reported, it has not been described in relation to metabolic syndrome (MetS), which often coexists with non-alcoholic fatty liver disease. We examined the association of a combination of liver abnormality and MetS with periodontal condition in Japanese adults, based on the level of alcohol consumption. In 2008, 4,207 males aged 45.4 ± 8.9 years and 1,270 females aged 45.9 ± 9.7 years had annual workplace health check-ups at a company in Japan. Periodontal status was represented as periodontal pocket depth at the mesio-buccal and mid-buccal sites for all teeth. Alanine aminotransferase (ALT), and metabolic components were examined. Multiple linear regression analysis showed a significant association between deep pocket depth and the coexistence of elevated ALT and MetS in males with low alcohol consumption. Females showed no such relationship. In conclusion, the association between periodontal condition and the combination of elevated ALT and MetS was confirmed in males. That is, a clear association between liver abnormalities and periodontal condition was seen in male subjects with no or low alcohol consumption and MetS, providing new insights into the connection between liver function and periodontal health. (J Oral Sci 57, 335-343, 2015)

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Previous studies have not resolved whether scaling and root planing with a full-mouth (with or without antiseptics) or quadrant approach is better for treatment of chronic periodontitis. We identified relevant studies and used Strength of Recommendation Taxonomy (SORT) criteria to critically interpret the results of all relevant studies. A literature search was performed using the PubMed, EMBASE, and Cochrane databases up to July 2015. Selected studies were stratified according to their quality, quantity, and consistency. In total, 377 studies were identified, and 36 articles selected for retrieval were stratified according SORT criteria, as follows: no level 1 studies, 15 level 2 studies, and 21 level 3 studies (which were excluded from subsequent analysis). Among the selected level 2 studies, including seven randomized clinical trials and three systematic reviews, 67% showed no significant difference between scaling and root planing with a full-mouth or quadrant approach. In conclusion, on the basis of the best available data, the strength of evidence is grade B (consistent, low-quality evidence) for full-mouth (with or without antiseptics) and quadrant scaling and root planing for treatment of chronic periodontitis. (J Oral Sci 57, 345-353, 2015)

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The aim of this study was to evaluate the relationship between pain intensities and psychosocial characteristics in middle-aged and older patients with temporomandibular disorders (TMDs) and burning mouth syndrome (BMS). Subjects were selected according to the Research Diagnostic Criteria for TMD (n = 705) and International Association for the Study of Pain criteria for BMS (n = 175). Patients were then divided into two age groups: 45-64 years (middle-aged, Group A) and 65-84 years (older, Group B). Pain intensity and depression and somatization scores were evaluated in both groups. In BMS patients, present and worst pain intensities were significantly higher in Group B than in Group A {4.6 [95% confidence interval (CI) = 4.0-5.2] vs. 3.5 [95% CI = 3.1-3.9] and 5.9 [95% CI = 5.2-6.4] vs. 5.0 [95% CI = 4.5-5.6], respectively; P < 0.05}, with no difference observed in TMD patients. The depression and somatization scores were significantly higher in Group A than in Group B among BMS patients [0.57 (95% CI = 0.45-0.69) vs. 0.46 (95% CI = 0.34-0.59) and 0.537 (95% CI = 0.45-0.63) vs. 0.45 (95% CI = 0.34-0.55); P < 0.05], with no difference observed in TMD patients. The results of the present study indicate that pain intensities and psychosocial characteristics in BMS appear to differ between middle-aged and older patients. (J Oral Sci 57, 355-360, 2015)

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This study used micro-CT to compare three obturation techniques with respect to void occurrence in canals filled with bioceramic sealer. Thirty extracted first mandibular premolars were prepared with a ProTaper Universal system and randomly allocated to three groups. Canals were obturated with gutta-percha and bioceramic root canal sealer, using either single-cone, lateral compaction, or Thermafil filling technique. Each tooth was then scanned with micro-CT. Voids in 2D cross-sectional images and void volumes in 3D images of all root thirds were assessed in relation to obturation technique. There was no significant difference between obturation techniques in the proportion of sections with voids (P > 0.05). However, the results of the obturation techniques significantly differed in relation to root region (P < 0.05). In conclusion, no root filling technique resulted in void-free specimens. Void volumes were highest for the single-cone technique and lowest for Thermafil, in all regions (P < 0.05). (J Oral Sci 57, 361-366, 2015)

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Using a mature biofilm model, the aim of this study was to evaluate the effectiveness of different antibacterial agents in comparison with silver diamine fluoride (SDF). Forty-eight saliva-coated enamel slabs were inoculated with Streptococcus mutans monospecies biofilm. The biofilms were then exposed to 10% sucrose in tryptone yeast-extract culture medium, 8 times per day for 7 days. After the biofilm growth period, the enamel slabs were treated with one of the following substances: 1) distilled water; 2) SDF; 3) acidulated phosphate fluoride (APF); 4) ammonium hexafluorosilicate (AHF); 5) ammonium hexafluorosilicate + cetylpyridinium chloride (AHF+CPC); or 6) 0.2% chlorhexidine (CHX). After these treatment procedures, the samples were incubated at 37ºC for 2 days, and the numbers of viable microorganisms in the biofilms were counted. The number of viable bacteria was significantly reduced by all of the antibacterial agents (P < 0.05). However, SDF showed the highest antibacterial activity (P < 0.05), and the effectiveness of the other agents was lower (P < 0.05). SDF has a highly effective antibacterial action against cariogenic Streptococcus mutans biofilm; none of the other fluoride agents used in this study, or 0.2 CHX agent, showed an antibacterial effect comparable to that of SDF. (J Oral Sci 57, 367-372, 2015)

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We measured the gonial angle (GA) on panoramic radiography (PR) and analyzed the correlation between the GA on PR and lateral cephalometric radiography (LCR). In total, 49 PR films and LCR films from dentate young adults were evaluated. Orthodontists plotted four points (articulare, menton, posterior gonion, and lower gonion) on the PR and carefully traced them. Using a protractor, two radiologists measured the GA on LCR images. A simultaneous experimental study of two dry skulls was performed to compare the GA on LCR and PR. The GA was slightly smaller on the PR of the dry mandible than on the LCR and tended to decrease continuously with magnitude toward the Frankfort horizontal plane. The mean GA was 115.1 ± 5.2° on PR and 122.2 ± 6.4° on the LCR. The values were highly correlated (Pearson product-moment correlation coefficient, 0.801). The GA on PR was nonsignificantly smaller than that measured on LCR. The difference may be due to head position, the inclination angle of the mandibular body, and/or the direction of the incident X-ray beam. (J Oral Sci 57, 373-378, 2015)

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The effect of brushing with two abrasive levels on the fluoride release of high-viscosity glass ionomers (GIs) was investigated. Forty-eight GI discs were fabricated and randomly assigned to one of the four groups. Treatments, performed for 30 days, included exposure to a carboxymethylcellulose (CMC) solution without fluoride (CMC-F), CMC with 275 ppm fluoride (CMC+F), CMC with fluoride plus brushing with a low abrasive slurry (relative enamel abrasivity = 4; L-ab), and CMC with fluoride plus brushing with a high abrasive slurry (relative enamel abrasivity = 7; H-ab). Fluoride release was measured after 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 days. Surface analysis was performed using optical profilometry in addition to scanning electron microscopy. Data were compared using one-way analysis of variance (α = 0.05). Fluoride release was significantly different among groups, with group H-ab showing the highest rates. Cumulative fluoride release was 10% and 30% greater in groups L-ab and H-ab than in group CMC+F. High surface roughness values were associated with H-ab as well as greater exposure of silica fillers, as observed by scanning electron microscopy. Fluoride release from conventional GIs is enhanced by brushing with high abrasive slurries. (J Oral Sci 57, 379-384, 2015)

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This clinical report describes the bonding procedure and clinical course of a natural tooth pontic in a 65-year-old male patient. A mandibular lateral incisor was extracted due to severe marginal periodontitis. The root of the tooth was amputated and a pontic structure was formed by filling acrylic resin into the coronal pulp chamber space. The enamel surface of the pontic and the adjacent abutment teeth were etched with phosphoric acid gel. The pontic was bonded with a modified tri-n-butylborane initiated adhesive resin (Super-Bond Quick). The connecters fractured 11 years after bonding when the patient accidentally bit a metallic chopstick. Recurrence of the fracture, however, did not occur, and the re-seated pontic has been functioning for more than 1 year. Although proper maintenance of both the periodontal tissue and splinted dentition is required, this minimally invasive technique can be applied in selected patients suffering from periodontal diseases. (J Oral Sci 57, 385-388, 2015)

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We describe a rare case of osteochondroma of the coronoid process of mandible accompanied by severe trismus in a 14-year-old Japanese boy. The patient had initially been diagnosed as having internal derangement of the temporomandibular joint (TMJ), and conservative treatment had failed to improve the symptoms. Despite extremely limited TMJ movement, panoramic radiography revealed no abnormality, but magnetic resonance imaging suggested internal derangement of the left TMJ. Five months later, the trismus worsened and computed tomography revealed a bone-like mass confluent with the coronoid process, which was finally diagnosed as osteochondroma. The patient then underwent intra-oral coronoidectomy. (J Oral Sci 57, 389-392, 2015)

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