Dental Research Journal
Volume:11 Issue: 3, May 2014

Traditional microbiology concepts are being renewed since the development of new microbiological technologies, such as, sequencing and large-scale genome analysis. Since the entry into the new millennium, a lot of new information has emerged regarding the oral microbiome. This revision presents an overview of this renewed knowledge on oral microbial community acquisition in the newborn and on the evolution of this microbiome to adulthood. Throughout childhood, the oral microbial load increases, but the microbial diversity decreases. The initial colonizers are related to the type of delivery, personal relationships, and living environment. These fi rst colonizers seem to condition the subsequent colonization, which will lead to more complex and stable ecosystems in adulthood. These early oral microbial communities, therefore, play a major role in the development of the adult oral microbiota and may represent a source of both pathogenic and protective microorganisms in a very early stage of human life. The implications of this knowledge on the daily clinical practice of odontopediatrics are highlighted.

The purpose of this review is to gain an overview of the applications of the dental pulp stem cells (DPSCs) in the treatment of various medical diseases. Stem cells have the capacity to differentiate and regenerate into various tissues. DPSCs are the adult stem cells that reside in the cell rich zone of the dental pulp. These are the multipotent cells that can be explained by their embryonic origin from the neural crest. Owing to this multipotency, these DPSCs can be used in both dental and medical applications. A review of literature has been performed using electronic and hand-searching methods for the medical applications of DPSCs. On the basis of the available information, DPSCs appear to be a promising alternative for the regeneration of tissues and treatment of various diseases, although, long-term clinical trials and studies areneeded to confi rm their effi cacy.

Localized gingival recession can be treated successfully via coronally positioned fl ap (CPF) and additional use of root surface demineralization agents. The purpose of this study was to evaluate the effects of additional use of ethylene diamine tetraacetic acid (EDTA) and citric acid as a root conditioner in association with CPF to cover localized buccal gingival recessions. Twenty-seven patients with 66 Miller class I buccal gingival recession ≥ 2 mm on single-rooted teeth were studied. Patients were randomly assigned: CPF with EDTA gel (test 1) and CPF with saturated citric acid (test 2) or CPF alone (control). Clinical parameters were measured at baseline and 1, 2, 3 and 6 months after surgery; assessment included recession depth (RD), clinical attachment level (CAL), probing depth (PD) and height of keratinized gingiva (HKG). SPSS version-20 was used to perform all statistical analyses. Data was reported as Mean ± SD. Age, RD, CAL, PD, and HKG before treatment and after 6 months among study groups were compared by one-way ANOVA followed by the Tukey test. The level of signifi cance was considered to be less than 0.05. At 6 months, all treatment modalities showed signifi cant root coverage and gain in CAL.RD was reduced from 2.86 ± 0.76 mm to 0.55±0.53 mm in the EDTA group and from 2.37±0.57 mm to 1.03±0.43 mm in the acid group and from 2.37±0.54 mm to 0.85±0.49 mm in the control group. The average percentage of root coverage for the EDTA, acid, and control groups were 80.73%, 52.16%, and 64.50%, respectively. At 6 months, there was a signifi cant difference (P < 0.05) in all parameters for the EDTA group (except HKG that did not vary among the groups). Root preparation with EDTA was an effective procedure to cover localized gingival recessions and signifi cantly improved the amount of root coverage obtained.

Proliferating cell nuclear antigen (PCNA) is a nuclear protein synthesized in the late G1 and S-phase of the cell cycle. Detection of this protein represents a useful marker of the proliferation status of lesions. This study has been carried out to evaluate the cell proliferation rate in oral lichen planus (OLP) and comparison between plaque and erosive lichen planus, which indicates the potential for malignant transformation. This study was comprised of 64 cases of histologically proven lichen planus, out of which 32 cases of plaque and erosive each was taken. Two sections were taken from each, one for H and E staining to verify histological diagnosis according to Eisenberg criteria, other sections were stained according to super sensitive polymer horse radish peroxidise method for identifying immunohistochemical expression of PCNA. Data were statistically analyzed by Tukey high-range statistical domain test. Statistically signifi cant P value was considered <0.05. In two types of lichen planus, erosive type (66.86%) showed higher expression of PCNA followed by plaque (17.07%). Overall, P value was <0.001, which was statistically signifi cant. It indicates that proliferation activity is more in erosive lichen planus followed by plaque type, which ultimately results in increased rate of malignant transformation. PCNA is a good nuclear protein marker to evaluate the proliferation status of OLP.Out of the two types of lichen planus, erosive type possesses more proliferative ratio and chances of malignant change is more in this type. It emphasizes the importance of long-term follow-up with erosive type when compared with plaque type.

Laser ablation has been suggested as an alternative method to acid etching; however, previous studies have obtained contrasting results. The purpose of this study was to compare the shear bond strength (SBS) and fracture mode of orthodontic brackets that are bonded to enamel etched with acid and erbium-doped yttrium aluminum garnet (Er:YAG) laser. In this experimental in vitro study, buccal surfaces of 15 non carious human premolars were divided into mesial and distal regions. Randomly, one of the regions was etched with 37% phosphoric acid for 15 s and another region irradiated with Er:YAG laser at 100 mJ energy and 20 Hz frequency for 20 s. Stainless steel brackets were then bonded using Transbond XT, following which all the samples were stored in distilled water for 24 h and then subjected to 500 thermal cycles. SBS was tested by a chisel edge, mounted on the crosshead of universal testing machine. After debonding, the teeth were examined under ×10 magnifi cation and adhesive remnant index (ARI) score determined. SBS and ARI scores of the two groups were then compared using t-test and Mann-Whitney U test. Signifi cant level was set at P < 0.05. The mean SBS of the laser group (16.61 ± 7.7 MPa) was not signifi cantly different from that of the acid-etched group (18.86 ± 6.09 MPa) (P = 0.41). There was no signifi cant difference in the ARI scores between two groups (P = 0.08). However, in the laser group, more adhesive remained on the brackets, which is not suitable for orthodontic purposes. Laser etching at 100 mJ energy produced bond strength similar to acid etching. Therefore, Er:YAG laser may be an alternative method for conventional acid-etching.

Caucasian norms are still used in the orthodontic treatment of Iranian patients, despite the different ethnic backgrounds of Iranians. The aims of this study were to evaluate the cephalometric features of an Iranian population and to establish cephalometric norms for Iranian living in the central region of Iran (Isfahan). A total of 238 lateral cephalometric radiographs and dental casts of Iranians (142 females and 96 males; aged 6-17 years) with acceptable profi les and Class I dental relationships were analyzed in fi ve age groups. The mean value, standard deviation and range of 20 angular and linear variables were calculated. The resulting norms for Iranian were compared with Caucasian norms and results of other studies on Iranian population using t-test. Male and female groups were also compared using the independent t-test (P < 0.05). Iranians tend to have an increased angle of convexity and IMPA (incisor to mandibular plane angle) and bimaxillary protrusion as compared with norms of Down‘s analysis. Anterior lower face height and anterior face height were greater than Burrstone’s sample measurement. Sella-Nasion (S-N) length was greater than Rakosi‘s norm. Iranians tend to have an increased ANB (A point-Nasion-B point) angle as compared with Steiner’s norms. Males tend to have greater cranial dimensions than females as indicated by the statistically signifi cant increase in anterior face height and S-N length (P < 0.05). Iranians have distinct cephalometric features, which should be used as a reference in treating Iranian orthodontic patients.

The global status report of the World Health Organization (WHO) on road safety suggested that India is leading in road traffi c accidents in the world. According to the report on road accidents in India in 2010 by the Transport Research Wing, Ministry of Road Transport and Highways, New Delhi, Kerala ranked third in accidents per lakh population and second in persons injured per lakh population. As the face, brain, and cervical spine are in close proximity with one another, associated injuries can be suspected. The aim of this study was to determine the relationship between the severity of head, cervical spine, and facial injury and incidence of facial injury in patients with head and/or cervical spine injury. A prospective cohort study was conducted over a period of one year. The study population included all patients having computed tomography (CT) demonstrable head injury, radiographic evidence of cervical spine injury, and associated head or cervical spine injury with facial injury. Data were analyzed using the chi-square test using statistical package SPSS. A P value less than 0.05 was considered statistically signifi cant. Of 124 patients, 59 (47.6%) had facial injuries. As severity of head injury increased, the number of facial injuries decreased. Statistically, no signifi cant association between facial and head injury was seen. A statistically signifi cant association between dentoalveolar involvement and cervical spine injury was seen (P < 0.001). The proportion of injuries in patients with cervical spine injuries alone was signifi cantly lower in the frontal (P = 0.001) and orbital (P = 0.004) regions and higher in the mandibular region (P = 0.010). Midface injuries were more commonly associated with head injuries. Decreased facial involvement leads to increased severity of head injury. Simple injuries of the cervical spine were more commonly associated with facial injuries.

The present study was undertaken to estimate and compare the levels of plasma total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), very low density lipoprotein (VLDL) and triglycerides in patients with oral precancerous lesions/conditions, oral cancer and normal subjects. The study comprised of 60 patients with oral precancerous lesions/ conditions, 60 patients with oral cancer and a control group of 60 healthy individuals. The diagnosis of oral precancerous lesions/conditions and oral cancer was confi rmed histopathologically. Under aseptic condition 5 ml venous blood of overnight fasting patient was withdrawn from each individual. Serum was separated by centrifugation and plasma levels of TC, LDL, HDL, VLDL and triglycerides were estimated. Descriptive statistical analysis has been carried out in the present study. Analysis of variance has been used to fi nd the signifi cance of study parameters between three or more groups of patients, Post-hoc test as Tukey has been used to fi nd the pair wise signifi cance. Signifi cance is assessed at 5% level of signifi cance. Statistically signifi cant decrease in levels of plasma TC, LDL, HDL, VLDL and triglycerides was observed in the precancerous and cancerous groups as compared to the control group. On comparison between precancerous and cancerous groups, signifi cant decrease was observed in cancerous group. The change in lipid levels may have an early diagnostic or prognostic role in the oral premalignant lesions/conditions and oral cancer. The presence of decreased plasma lipid profi le should increase the suspicion of these lesions to be investigated further.

It is known that dental unit waterline can be a source of infection. The aim of this study was to evaluate the effi cacy of a mouthwash, chlorhexidine, in controlling microbial and fungal contamination of dental unit waterlines. In the present experimental study, the water in high-speed handpieces and air/water syringes of 35 dental units in a dental school was investigated microbiologically. Five of the units and one tap water served as controls; 100-200-mL water samples were collected aseptically in sterile containers in the morning after a 2-min purge. Water reservoir bottles were emptied and 50 mL of 0.2% chlorhexidine mouthwash was introduced into the tank. Then the water syringe was used to fl ush the waterline until the pink-colored chlorhexidine was observed to fl ow from the water syringe. Before the next day’s session and before the students used the unit, two water samples from the water syringe and water turbine was collected. The samples were transferred to the laboratory. After 48 h at 37°C, the microbial colonies were counted. The number of these colonies was evaluated using colony forming unit CFU. Data were analyzed with Mann — Whitney U test and SPSS 13.5 statistical program. The statistical signifi cance was defi ned at P ≤ 0.05. All 35 units were contaminated before chlorhexidine use; no contamination was detected after adding chlorhexidine to the waterlines of the units. After week 1, 28 of the 30 treated dental unit waterlines (DUWLs) had values of CFU/mL less than 200. The present study showed that the use of chlorhexidine could reduce microbial counts in dental unit waterlines.

Osteoclastogenesis is coordinated by the interaction of members of the tumor necrosis factor (TNF) superfamily: Receptor activator of nuclear factor-κB ligand (RANKL) and Osteoprotegerin (OPG). The aim of this study was to compare the effect of two different types of non-steroidal anti-infl ammatory drugs (NSAIDs) on the RANKL/OPG balance during the healing of the alveolar process. This was an experimental study, carried on 45 male Wistar rats (200 ± 25 g, 8-10 weeks old). After extraction of the right maxillary fi rst molar, 15 rats received 5 mg/kg/ day of diclofenac and 15 rats received 15 mg/kg/day of celecoxib and 15 rats received normal saline.The animals were sacrifi ced 7, 14 and 21 days after tooth extraction. The number of osteoclasts, OPG and RANKL messenger ribonucleic acid expression were determined by tartrate-resistant acid phosphate (TRAP) staining and polymerase chain reaction (PCR) respectively. The data were analyzed by one-way ANOVA followed by Tukey’s post-hoc test. Values of P < 0.05 were considered signifi cant. On days 7, 14 and 21 the ratio of RANKL/OPG in the control group was higher than diclofenac and celecoxib groups. TRAP immunolabeling of the control group was more than diclofenac group on day 7 and was more than celecoxib group on day 14. On day 21, no signifi cant differences were noted among the three studied groups. Both drugs affect RANKL/OPG gene expression and also osteoclastogenesis in alveolar socket during the experimental period of 21 days.

The aim of the present study was to investigate the quality of root canal obturation performed by 6th year undergraduate dental students at the Dental School, University of Mashhad, Iran. A random 200 sample records of patients who received endodontic treatment at the Dental School, University of Mashhad between 2009 and 2010 was investigated. The quality of root canal fi lling was determined in relation to the adequate density and length of root fi lling. Statistical analysis of the data was carried out using statistical package for the social sciences (SPSS 12.0, SPSS Inc., Chicago, IL, USA) with Chi-square test. P < 0.05 was considered as signifi cant. About 38% of teeth fulfi lled the criteria of an acceptable root canal fi lling. Adequate length and density of root fi lling was found in 73% and 66% of teeth respectively. There was signifi cant difference between maxillary and mandibular teeth according to the quality (P = 0.009), length (P = 0.039) and density (P = 0.005) of root fi lling. The frequency of root canals with an “acceptable”fi lling was signifi cantly greater in the anterior teeth than in molars. The technical quality of root canal treatment performed by undergraduate dental students was found to be less than ideal. Thus, the training course of the students at the preclinic and clinic has to be revised.

Salivary gland tumors constitute an important part of oral and maxillofacial pathology. Pleomorphic adenoma (PA) and mucoepidermoid carcinoma (MEC) are the most common benign and malignant salivary gland tumors. Fascin is an actin-bundling protein that increases the motility of normal and transformed epithelial cells. The aims of the study were to determine the expression of fascin in these tumors and to determine its role in their progression. A total of 40 formalin-fi xed, paraffi n-embedded tissue blocks of PA, and 20 blocks of MEC were included in this study. Diagnostic confi rmation was performed through examination of hematoxylin and eosin sections. Both tumors were immunohistochemically analyzed for the presence of fascin using Avidin-Biotin complex method and evaluated via light microscope by 2 independent observers. Statistical analysis was performed using Kruskal-Wallis and Chi square tests with signifi cant level of P < 0.05. In both the tumors, the percentage of stained cells was signifi cantly correlated with intensity of staining (P = 0.01 in PA and P = 0.00 in MEC). In PA, statistical analysis showed a signifi cant direct correlation between percentage of stained cells and recurrence (P = 0.00). There was no significant correlation between intensity and percentage of staining with clinicopathologic factors in MEC. Fascin might be a useful marker for recurrence of PAs and patients with high fascin expression in primary PA should be followed up periodically to detect potential recurrence as soon as possible.

This study sought to assess symphyseal morphology in adolescents with different mandibular growth patterns (MGPs) in order to see if a relation exists. In this study the symphyseal parameters (height, depth, and ratio) of normal subjects were compared with four groups with malocclusion (cl III vertical, cl II vertical, cl III horizontal, and cl II horizontal). These groups (15 samples each) were matched (for sex and cervical maturation stage [CVMS]) based on their cephalograms and patient charts. Growth patterns were differentiated by seven vertical parameters and the Wylie analysis. After confi rmation of normality of the groups and similarity of their variances the two-way analysis of variance (ANOVA) was used for analysis of data assessed by adjusted chi-square (P < 0.001). The comparison of cases with the normal group was performed by the Dunnett method. Intraclass Correlation Coeffi cient (ICC) was used for evaluation of intraobserver reliability. We found the symphyseal ratio to have a signifi cant correlation with the MGP (P < 0.001). The symphyseal ratio (Height/Depth) was small in a mandible with vertical growth pattern Cl II or Cl III. Conversely, a horizontal growth pattern of a Cl II or Cl III mandible was associated with a larger ratio of the symphysis in comparison with the normal group. The symphyseal ratio was also found to be greater in females. The symphyseal ratio was found to be strongly associated with the MGP.

The association of Epstein-Barr virus (EBV) with Burkitt’s lymphoma (BL) is variable in different geographic regions. In developing countries, the association of EBV with BL is regarded to be of an endemic-type in equatorial Africa (> 95%) and sporadic-type in the developed countries (15-30%). The purpose of this study is to assess the frequency of EBV infection in BL, in Iran. The study also aims to compare Ribonucleic acid (RNA) in situ hybridization (RISH), the standard diagnostic method, with the polymerase chain reaction (PCR)-based method for diagnosing BL. In this epidemiological study, the paraffi nized specimens of 18 cases of BL were selected. Next, the ISH of EBV-encoded RNA (EBER-RISH) and PCR assays that were based on Epstein Barr Nuclear Antigen 2 (EBNA2) amplifi cation were used. The EBV strain was determined by PCR. The data were analyzed using the SPSS10 software and by performing Pearson correlation coeffi cient formula at a signifi cant level of 0.05. EBV RNA was detected in 50% of the BL specimens. Type 1 and 2 accounted for 70 and 30% of the cases, respectively. Regarding RISH as the standard method for EBV diagnosis, the PCR assays showed a sensitivity and specifi city of 100 and 88.9%, respectively. According to the obtained fi ndings, the frequency of EBV in BL was 50% and PCR and RISH showed high concordance and sensitivity in EBV detection. Therefore, PCR can be used as a faster method for EBV detection in high-risk geographical regions.

Gingival involvement is commonly seen in lichen planus, a chronic mucocutaneous infl ammatory condition of the stratifi ed squamous epithelia. It is often painful and may undergo malignant transformation and thus warrants early diagnosis and prompt treatment. The aim of this study is to evaluate the use of a bioresorbable membrane (Polyglactin 910) in the management of erosive lichen planus of gingiva. A split-mouth randomized controlled trial was carried out. Fifteen patients with identical bilateral lesions of lichen planus on gingiva were included in the study. Three parameters were selected for the clinical assessment of gingival lesions: Surface texture, color, and burning sensation. After complete oral prophylaxis, an excisional biopsy procedure was carried out for lesions on both sides, but on the experimental side, the biopsy procedure was combined with placement of the bioresorbable membrane. The statistical signifi cance of intergroup differences in measurements was tested by using an independent sample t-test. A two-tailed P-value less than 0.05 was considered as statistically signifi cant. Intragroup comparisons revealed a statistically signifi cant difference between mean value of grades at 6, 12, and 24 weeks in both groups for the surface texture, color, and burning sensation of gingiva, respectively. For intergroup comparison of change in surface texture, color, and burning sensation of gingiva between group A and group B, differences were statistically nonsignifi cant. Surgical management of the lesion accomplished signifi cant improvement of lesion with no signifi cant additional clinical benefi ts with the application of bioresorbable membrane. Worsening of baseline scores was not observed in any case at the end of the study.

Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX. Samples were divided into eight experimental groups: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/ deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test. In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours. Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound.

Pyogenic granuloma (PG) is a well-known benign non-neoplastic overgrowth. It is a response to mild irritation and might be related to hormonal factors and certain kinds of drugs. PG preferentially affects the gingiva, but can be found extragingivally with varying clinical features. The most common treatment is surgical excision. This article describes a case of extragingival PG occurring on the tongue with unusual presentation, with emphasis on non-surgical treatment. Since surgical management had not been successful, an alternative approach was taken. We illustrated how the lesion was successfully treated with a series of intralesional corticosteroid injections.

Malignant peripheral nerve sheath tumor (MPNST), the principle malignancy of peripheral nerve origin, though rare in the general population, occurs with excessive frequency among patients with neurofi bromatosis. This tumor always arises in soft-tissues, usually found in the lower extremities and only 10-12% of all lesions occur in the head and neck region, which makes it a rare entity. The primary intraosseous MPNST is rare and has been reported most frequently in the mandible. This article discusses a case report of MPNST of the left maxilla without a history of benign nerve tissue tumor and the diagnostic diffi culties associated with MPNST.

Neoplasms that arise in the salivary glands are relatively rare, yet they represent a wide variety of both benign and malignant histologic subtypes. Approximately 70% of the salivary gland tumors affect parotid gland with the submandibular gland being affected in 5-10% of the cases, sublingual gland in 1% and minor glands in 5-15% of the cases. Submandibular gland tumors are relatively rare and very few studies have been reported in the literature that is exclusively conducted on tumors affecting submandibular gland. In this paper, we describe a case of pleomorphic adenoma affecting submandibular gland with brief review of current literature on submandibular gland tumors.

Extensive breakdown of primary teeth to the cervical level and their loss in very young children is not uncommon. Owing to increasing concerns over self-appearance, due considerations to esthetic aspects in addition to restoring function are necessary aspects of rehabilitation of mutilated teeth to help children grow into a psychologically balanced personality. The present article describes rehabilitation of grossly decayed teeth with biologic restorations such as dentine posts, dentine post and core and biologic shell crown. This treatment modality provided a cost-effective esthetic solution.