Periradicular surgery is often used as a last resort to save an endodontically treated tooth with a persistent periapical lesion. The introduction of surgical microscopes, ultrasonics, and compatible root-end filling materials has made periradicular surgery a much more predictable treatment. The advantages of modern periradicular surgery include easier identification of root apices, smaller osteotomines, shallower resection angles, and tight sealing within the prepared root-end cavity. Modern periradicular surgical thus has a much higher success rate than traditional periradicular surgery. (J Oral Sci 55, 267-273, 2013)
The aim of the present study was to compare the in vitro antibacterial activity of common root canal irrigants with a combination technique against intratubular Enterococcus faecalis. Seventy-five human single-rooted teeth were selected and their crowns and root-ends were removed to obtain specimens 5 mm in length. The specimens were contaminated with E. faecalis and divided into five experimental groups (n = 15). These groups were irrigated with 2% chlorhexidine (CHX), 3% hydrogen peroxide (H2O2), 5.25% sodium hypochlorite (NaOCl), CHX/H2O2 and sterile saline (control). Surface and deep dentinal chips were collected for each sample. After incubation, the numbers of colony-forming units (CFUs) were counted. The Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis (α = 0.05). In the surface dentin, CHX, NaOCl, and CHX/H2O2 had significantly higher antibacterial activity than H2O2 (P < 0.05). In the deep dentin, NaOCl and CHX/H2O2 had significantly higher antibacterial activity than CHX and H2O2 (P < 0.05). CHX/H2O2 had similar antibacterial effectiveness to NaOCl in both surface and deep dentinal tubules. This combination can be considered a potentially useful irrigant for root canal treatment. (J Oral Sci 55, 275-280, 2013)
We investigated the association between polymorphisms in the MMP2 (rs243865), MMP9 (rs17576), and MMP13 (rs2252070) genes with tooth agenesis in humans. Two hundred eighty-five unrelated individuals (202 controls without tooth agenesis and 83 cases with tooth agenesis) were evaluated in a cross-sectional single-center study. The study participants were recruited through the Pediatric Dental Clinics of the Federal University of Rio de Janeiro, Brazil. Genotyping of the selected polymorphisms for MMPs was carried out by real-time PCR using the Taqman assay method from genomic DNA isolated from buccal epithelial cells of all the studied individuals. There was no significant association of MMP2 genotype or allele distribution with tooth agenesis or its absence. For MMP9, a significant difference in allele frequency was evident between the two groups (P = 0.05). With regard to the affected side, there was a significant difference between unilateral tooth agenesis and the control group in the distribution of MMP9 (P = 0.05). Also, there was a significant difference in MMP9 distribution between tooth agenesis in the maxilla and control individuals (P = 0.03). The genotype distribution of MMP13 differed significantly between the group with unilateral tooth agenesis and the controls (P = 0.01). Our findings provide evidence that MMP9 and MMP13 may be involved in tooth agenesis. (J Oral Sci 55, 281-286, 2013)
We used denaturing gradient gel electrophoresis (DGGE) to compare bacterial profiles in periodontium and root canals of teeth with combined periodontal-endodontic lesions. Samples of dental plaque and necrotic pulp were collected from thirteen extracted teeth with advanced periodontitis. Genomic DNA was extracted for polymerase chain reaction (PCR) analysis using universal bacterial primers. The PCR products were then loaded onto DGGE gels to obtain fractionated bands. Characteristic DGGE bands were excised and DNA was cloned and sequenced. The number of bands, which indicates the number of bacterial species, was compared between dental plaques and necrotic pulp tissues from the same tooth. Although the difference was statistically significant (P < 0.01), there was no positive correlation; similarity (Dice coefficient) was 13.1% to 62.5%. Some bacteria species were present in both the periodontal pockets and root canals of the same tooth; however, periodontal bacteria did not always invade the root canals, and some bacteria in root canals were not present in periodontal pockets of the same tooth. In some teeth, unique bacteria in root canals had not passed from periodontal pockets. A basic local alignment search tool (BLAST) sequence search in Genbank indicated that new bacteria species were present in periodontal pockets and root canals. Their characteristics must thus be further analyzed. (J Oral Sci 55, 287-291, 2013)
Oral epithelial dysplasia is thought to be a precursor state of carcinogenesis and may harbor gene alterations. Recently, it was reported that gene editing enzyme, activation-induced cytidine deaminase (AID), is expressed in precursor and cancer epithelial cells during carcinogenesis associated with chronic inflammation/infection and that this enzyme induces mutation of tumor-suppressor genes. Thus, AID may have a role in carcinogenesis via oral epithelial dysplasia. In this study, we classified oral mucosal epithelium exhibiting epithelial dysplasia as squamous intraepithelial neoplasia (SIN) grades 1-3, according to the 2005 World Health Organization classification, and used immunohistochemical techniques to examine AID expression in oral mucosal epithelium exhibiting SIN and oral cancer tissues. AID was observed in prickle cells in oral mucosal epithelium with epithelial dysplasia and in oral cancer cells. Additionally, to investigate the mechanism of AID expression and its role in cancer progression, we incubated the oral cancer cell line HSC-2 with inflammatory cytokines. In the HSC-2 cell line, AID expression was enhanced by TNF-α via NF-κB activation and promoted expression of N-cadherin by regulating Snail expression. These findings suggest that AID has a role in the development of oral epithelial dysplasia and promotes progression of oral cancer. (J Oral Sci 55, 293-299, 2013)
We evaluated the effectiveness of the experimental surface pre-reacted glass-ionomer coating (SI-R20401) to remineralize artificial enamel lesions in primary teeth. For each of 12 sound primary molars, five regions were assigned, based on whether enamel was unground or ground and whether PRG coating was applied. The teeth were demineralized in 10% EDTA for 7 h and lactic acid solution for 3 days and immersed in artificial saliva (Group 1), demineralizing medium (Group 2) or deionized water (Group 3) for 1 month. DIAGNOdent reading, nanoindentation test and scanning electron microcopy/energy dispersive X-ray analysis were performed. Data were analyzed using analysis of variance and the Fisher protected least significance difference test at α = 0.05. After immersion, a decrease in DIAGNOdent value for the demineralized enamel was observed only in the unground/non-PRG region of Group 1. In the ground/PRG region of Groups 1 and 3, the hardness and Young’s modulus at the enamel surface were significantly higher than those at subsurface points. For unground enamel, Ca%, P%, and the Ca/P ratio at the enamel surface of the non-PRG region were significantly lower than those at subsurface points. In Group 2, scanning electron microcopy showed greater demineralization at the unground/non-PRG region compared with the unground/PRG region. Efficacy of SI-R20401 to remineralize the enamel lesions in primary teeth was partially observed, however, to arrest the lesion could not be demonstrated. (J Oral Sci 55, 301-310, 2013)
Lichen planus is a chronic, autoimmune, mucocutaneous disease that shows differences in clinical presentation at different times of the year. The present retrospective study was conducted to clarify the meteorological factors that influence the incidence of lichen planus, as well as the general features and clinical presentation of this condition during three consecutive years, 2008, 2009, and 2010, in Moradabad district (Western Uttar Pradesh, India). The study group comprised 1,355 patients extracted from the records of the outpatient department of Kothiwal Dental College Research Centre and Hospital, who were clinically diagnosed as having lichen planus during this three-year period. The highest number of patients (735) were recorded in summer, and the lowest (56) in winter. Females were affected more often, and psychosocial influences were also evident. There were significant differences in the incidence of lichen planus in different seasons, and the summer peak was attributable to the intensity of sun exposure (actinic lichen planus and summertime lichen planus). (J Oral Sci 55, 311-318, 2013)
IGF-1 regulates the metabolism of hard dental tissue through binding to the IGF-1 receptor on target cells. Furthermore, IGF-binding-protein-3 promotes the accessibility of IGF-1. The aim of this study was to investigate the expression of IGF-1, IGFBP-3 and IGF-1R in STRO-1-positive dental pulp stem cells (DPSCs) and fully impacted wisdom teeth in relation to tooth development. Third molars were surgically removed from 60 patients and classified into two groups: teeth showing ongoing development (group 1) and teeth that had completed root shaping (group 2). The transcript and protein levels of IGF-1, IGFBP-3 and IGF-1R were investigated using RT-PCR and immunohistochemistry. The expression of the same proteins was also analyzed in DPSCs. The teeth from group 1 showed significantly stronger expression of IGF-1 and IGF-1R. The major sources of all of the proteins investigated immunohistochemically in sections of wisdom teeth were odontoblasts, cementoblasts and cell colonies in the pulpal mesenchyme. These colonies were identified as stem cells in view of their positivity for STRO-1, and the cells were subsequently sorted by flow cytometry. These DPSCs demonstrated high levels of pluripotency markers and IGF-1 and IGF-1R. We conclude that members of the IGF-1 family are involved in the late stage of tooth development and the process of pulpal differentiation. (J Oral Sci 55, 319-327, 2013)
This cross-sectional survey was conducted to assess the prevalence and severity of dental erosion and to determine the potential risk factors for dental erosion among 11- to 14-year-old school children in South India. The total sample size for the study was 605, of which 303 school children were from private schools and 302 from public schools. A questionnaire was designed to record information about socio-demographic characteristics, oral hygiene practices, dietary habits and risk factors for dental erosion. Chi square test, bivariate analysis and Logistic regression analysis were performed to analyse the data. The children who consumed lemon several times a day (OR = 13.41, P < 0.001), and those who preferred carbonated drinks (OR = 2.80, P = 0.007) had a higher tendency to develop dental erosion. The overall prevalence of dental erosion was found to be low (8.9%). Erosion was found to be greater in posterior teeth (65.6%) than anterior teeth (34.4%). Loss of enamel only with loss of surface contour was observed in most (94.8%) of the cases. The prevalence of dental erosion was found to be low in school children. Private school children were affected more by dental erosion. Frequency of lemon consumption and consumption of carbonated drinks were identified as risk factors. (J Oral Sci 55, 329-336, 2013)
Carious tooth surfaces can alter saliva in various ways. We investigated whether salivary parameters were affected by elimination of existing active dental caries in 99 children (age 6-12 years) with more than five carious tooth surfaces. Unstimulated saliva samples were obtained from each child, and salivary characteristics were evaluated. One month after caries treatment that eliminated all existing dental caries, saliva sampling and analysis were repeated. Saliva viscosity significantly decreased (P = 0.04), while pH and saliva buffering capacity significantly increased (P < 0.001). There was no significant difference in unstimulated salivary production at the start of the study and 1 month after caries elimination (P > 0.05). The relationship between dental caries and salivary condition is reciprocal. Treatment of existing dental caries can prevent future caries by improving saliva quality. (J Oral Sci 55, 337-342, 2013)
Using in vivo microfocus computed tomography (micro-CT) and tissue sections, we evaluated bone regeneration in non-critical-sized rat calvarial flat bone defects during systemic administration of lactoferrin (LF). Ten 11-week-old male Fischer rats were used. Non-critical-sized calvarial bone defects (diameter, 2.7 mm) were trephined into the dorsal parietal bone on both sides of the midsagittal suture, and a collagen sponge soaked in saline was placed on each side. LF was injected intraperitoneally every day, starting on the day of the operation (day 0; groups: control, 10 mg/kg LF, 100 mg/kg LF). Micro-CT imaging was performed repeatedly from 1 to 4 weeks after surgery. The defect sites were then removed, along with surrounding bone and soft tissues, and stained with hematoxylin and eosin. During weeks 1-4, micro-CT showed a significant difference in reossification ratio between the controls and the 100 mg/kg LF group. Histological analysis revealed that there were more osteoblast-like cells around the bony rim in the 100 mg/kg group than in the control group. In summary, micro-CT and histological analyses showed that systemic administration of LF accelerated bone regeneration in non-critical-sized rat calvarial bone defects. (J Oral Sci 55, 343-348, 2013)
This study aimed to assess self-reported chewing ability among a sample of Sudanese adults and to identify factors associated with impaired oral function. A total of 1,888 adults (≥16 years old) attending outpatient clinics in Khartoum State were included. Subjective chewing ability was assessed by interviewing participants on chewing complaints and perceived difficulty of chewing 15 common Sudanese foods. Pearson and multivariate analyses were used to examine relationships between chewing ability and characteristics obtained from interviews and clinical examination. Chewing complaints were reported by 33.5% of subjects; 15.2-33.4% had perceived difficulty of chewing hard foods, whereas only 1.5-6.9% had difficulty eating soft foods. The likelihood of chewing complaints was higher in people with dry mouth, <20 teeth, tooth decay, poor self-rated oral health, perceived difficulty of chewing, and higher oral health-related quality of life (OHRQoL) scores. Individuals with <20 teeth, poor self-rated general health, and higher OHRQoL scores were all more likely to have perceived difficulty of chewing certain foods. Impaired chewing ability was rather highly prevalent among Sudanese adults. Addressing factors such as dry mouth and tooth loss/decay, which have been identified to be associated with impaired oral function, might help to decrease the risk of omission of essential foods from the diet and improve OHRQoL. (J Oral Sci 55, 349-357, 2013)
The periodontal status of patients with laryngo-onycho-cutaneous syndrome is unknown. This study describes a case of severe aggressive periodontitis in a 19-year-old American-Pakistani female with laryngo-onycho-cutaneous syndrome. The patient showed abundant dental plaque and calculus accumulations, suppuration and hemorrhage from virtually all gingivae and interdental papillae, and extensive radiographic alveolar bone loss and vertical mobility of several teeth. Subgingival plaque samples revealed a variety of major periodontal pathogens. The patient was scheduled for full-mouth tooth extraction. (J Oral Sci 55, 359-362, 2013)
Several growth factors have been used in tissue regeneration therapy. Here we describe the use of an autologous blood clot combined with gelatin for teeth affected by severe periodontitis and vertical root fracture treated using three oral surgical procedures: periodontal flap surgery, intentional tooth replantation (IR), and tooth autotransplantation. Treatment with a blood clot improved the condition of the periodontal tissue, including reduction of pocket depth. Radiographical images demonstrated no evidence of ankylosis, and revealed the presence of alveolar bone regeneration. Our successful clinical outcome suggests that use of an autologous blood clot combined with gelatin is clinically effective for regeneration of lost periodontal tissue. (J Oral Sci 55, 363-366, 2013)
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