Dental Research Journal
Volume:9 Issue: 2, Mar 2012

Local anesthesia forms the major part of pain-control techniques in dentistry. The prevention and elimination of pain during dental treatment has benefited patients, their doctors and dental hygienists, enabling the dental profession to make tremendous therapeutic advances that would otherwise have been impossible. Introduced in the late 1940s, the amide local anesthetics represent the most used drugs in dentistry. Local anesthetics also represent the safest and most effective drugs in all of medicine for the prevention and management of pain. They are also accompanied by various adverse effects which should be well known and be able to be controlled by the clinician. The article reviews the types of agents used as local anesthetics and their effects on the human body.

Properties of coated archwires, which have been introduced for esthetic demands during orthodontic treatments, along with the use of tooth-colored brackets, are not clear. The aim of this study is to compare the load-deflection and surface properties of coated superelastic archwires with conventional superelastic archwires in conventional and metal-insert ceramic brackets. In this experimental study, 3 types of archwires including ultraesthetic polycoated, ultraesthetic epoxyresin coated and conventional (uncoated) superelastic nickel-titanium (NiTi) archwires were used in each of 2 types of brackets including conventional and metal-insert ceramic. To simulate oral environment, all specimens were incubated in artificial saliva using thermocycling model and then were tested in three-bracket bending test machine. Loading and unloading forces, plateau gap and end load deflection point (ELDP) were recorded. Archwires were investigated with a stereomicroscope before and after the experiment. Two-way ANOVA and Tukey tests were used at P<0.05. Epoxyresin archwires produced lower forces (19 to 310 gr) compared to polycoated (61 to 359 gr) and NiTi (61 to 415 gr) (P<0.0001). The maximum ELDP (0.43 mm) was observed in epoxyresin archwires (P<0.001). Coatings of some epoxyresin wires were torn and of polycoated wires peeled off. Conventional ceramic bracket produced higher loading forces with polycoated and NiTi archwires and lower unloading forces with all 3 types of archwires compared to metalinsert type (P<0.05). Epoxyresin-coated archwire had the lowest force and highest ELDP. Coatings were not durable in these experimental conditions. Conventional ceramic bracket produced higher frictional force compared to metal-insert type.

As glass ionomers have the ability to reload fluoride from outside sources, the aim was to compare the recharge pattern of six glass ionomer cements after exposure to fluoride. Fuji VII, Fuji IX, Riva Pink, Riva Bleach, Ketac Fil and Fuji IX Extra were investigated. The fluoride-containing materials used were tooth paste and mouth wash (Colgate). Specimens of each material (n=15) were immersed separately in deionized water for 59 days. Then the samples of each material were divided into three groups of five each. Two groups were recharged for 2, 20 and 60 min daily during three consecutive weekly intervals and then no treatment for one week. The third group was used as control. Fluoride release measurements (μg/cm2/day) were made in every 24 h. One-way and repeated measures analysis of variance tests were used. Tooth paste recharged materials showed higher level of recharge. On day 1, the difference of fluoride release from different treatment groups of different materials except for Fuji IX Extra were not significant (P>0.05). On days 7 and 14, the differences observed were significant (P<0.05) for all materials except for Fuji VII (tooth paste versus mouth wash) and Trial Fuji IX (mouth wash versus control) and on day 14 for Rvia Pink (mouth wash versus control). On days 21 and 28, the differences observed were significant for all the materials (P<0.05) except for Riva Pink (toothpaste versus mouth wash), Riva Bleach, Ketac Fil and Trial FujiI X (mouth wash versus control) on day 28. A time tabled schedule of application of fluoride-containing materials could help to achieve high fluoride release.

Root canal cleaning is an important step in endodontic therapy. In order to develop better techniques, a new generation of endodontic instruments has been designed. The aim of this study was to compare the effectiveness of manual K-files (Mani Co, Tokyo, Japan) and two rotary systems–Mtwo (Dentsply-Maillefer, Ballaigues, Switzerland) and ProTaper (VDW, Munich, Germany)–for root canal preparation in primary molars. India ink was injected to 160 mesiobuccal and distal root canals of mandibular primary molars. The teeth were randomly divided into three experimental groups and one control group. In each experimental group, either manual instruments (K-files) or rotary instruments (Mtwo or ProTaper) were used to prepare root canals. After cleaning the canals and clearing the teeth, ink removal was evaluated with a stereomicroscope. Statistical analysis was done with Kruskal–Wallis and Friedman tests. There were no significant differences in cleaning efficiency between manual and rotary instruments. Only ProTaper files performed significantly better in the coronal and middle thirds than in the apical third of the root canal. Manual K-files and the Mtwo and ProTaper rotary systems showed equally acceptable cleaning ability in primary molar root canals.

The aim of the present study is to determine the number of third molars per person, angulation, level, amount of space for eruption of third molar between ramus of mandible and second molar and the eruption status of third molar in a group of Libyan students, with different impaction patterns and agenesis of third molars. In this descriptive retrospective study, a total of 200 students (100 male and 100 female students of bachelor of dental surgery, Faculty of Dentistry, Garyounis University, Benghazi, Libya) were enrolled. Students who had complete complement of teeth within the age group 17–26 years were selected for this study, while those cases who had history of extraction of any of the teeth or who refused to give consent were excluded. Before starting the study, ethical concern from the ethical committee, IRB and informed consent from each student who underwent radiography were obtained. The results showed that 5% of third molars were congenitally missing. Approximately 93.5% of the subjects had all four third molars, 1% had two third molars and 0.5% had one third molars with 2.5% having agenesis of all third molars. Third molar agenesis showed predilection for maxilla with higher proportion in females (3%) than males (2.1%). Angular position was maximum with vertical position (5.83%), with least being horizontal impactions. Level of occlusal plane of third molar similar to that of adjacent tooth was seen in 44.74%, below the occlusal plane in 24.76%, totally impacted noted in 30%. The present study showed that 33% of the teeth were fully erupted and 66% were in various stages of eruption and 5% were congenitally missing in these students.

Leukoplakia is a common, potentially premalignant lesion with malignant transformation rate from 1 to 17% with highest transformation rate for the lesions on the floor of the mouth, soft palate and tongue. One of the main etiological factors is consuming areca nut and its commercial preparations which generate high levels of reactive oxygen species during their metabolism. So the aim of this present study is to evaluate the plasma levels of antioxidant vitamins, antioxidant mineral zinc, glutathione and total antioxidant status (TAS) in leukoplakia patients. For this cross-sectional study, we selected 23 newly diagnosed oral leukoplakia patients of both sexes within the age group 28–40 years and the same number of age and sex matched healthy individuals without having history of any systemic illness were selected as control group. In both the groups, we measured plasma antioxidant vitamins A, C, E, antioxidant mineral zinc, GSH and TAS. Student’s t test was applied and the P value <0.001 was considered as statistically significant. We observed very low levels of antioxidant vitamins A, C, E, antioxidant mineral zinc and antioxidant metabolite GSH (P<0.001) and at the same time we also observed very poor (TAS) (P<0.001) in leukoplakia patients when compared to patients in control group. The consumption of tobacco or areca quid which contains high copper levels creates an oxidative stress like environment during their metabolism, might play a major role in causation and propagation of oral leukoplakia.

Heat shock proteins (HSPs) are a family of proteins that are known to play a significant role in the repair of denatured proteins in the cell. It seems that cytoprotective properties of HSPs may help in malignant progression by facilitating tumor cell growth and survival. The purpose of this study is to evaluate HSP27 and HSP70 expression in various histopathological grades of squamous cell carcinoma (SCC). In this retrospective-analytical study, the sections of 51 formalin-fixed paraffin-embedded biopsy specimens of SCC from various sites of oral and paraoral regions and 10 normal oral mucosa were immunostained by Novolink Polymer technique to determine the expression of HSP27 and HSP70. Then the data were analyzed according to the Kruskal–Walis, Mann–Whitney and the Spearman correlation tests (P<0.05). The expression of HSP27 in well-differentiated SCC was significantly higher than normal epithelium (P=0.007) and in moderately differentiated SCC higher than poorly-differentiated SCC (P=0.023). Inverse correlation was observed between HSP27 expression and SCC’s histopathological grade (P=0.001, r=-0.448). There was no significant difference between HSP70 staining of specimens (P=0.38). The present study revealed that the expression level of HSP27 was inversely related to histopathological grade of SCC and it may provide prognostic value for patients with SCC, but there was no significant relationship between the expression of HSP70 and histopathological grades of SCC.

Antimicrobial activity of interappointment intracanal medications is an important consideration in endodontics. Considering the fact that calcium hydroxide (CH) cannot sterilize the root canal system, completing its antimicrobial spectrum seems necessary. The aim of this study was to compare the antibacterial activity of CH combined with three different vehicles in root canal system. In this in vitro experimental study, 61 freshly extracted human single rooted teeth were used. After chemo-mechanical preparation, the teeth were dressed with CH in combination with: G1: Distilled water (DW); G2: 5.25% sodium hypochlorite; G3: 0.2% chlorhexidine solution. All teeth were mounted in a 2-chamber apparatus. After sterilization, the coronal chamber was exposed to bacteria and the apical chamber was filled with broth for 90 days. Leakage was recorded when turbidity was observed in broth. Mean times of leakage and turbidity percentage were recorded for each group. Data were analyzed by One Way ANOVA test (a=0.005). The highest mean time of contamination was for chorhexidine/CH combination (M=66.76 days), and the lowest was for DW/CH combination (M=40.29 days). Statistically significant difference was observed between G3 and G1 (P=0.042), but the difference between G2 and G3 (P=0.76) or G1 and G2 (P=0.18) were not significant. 88.23% of the samples of G1, 70.58% of G2, and 64.70% of G3 were contaminated after 3 months. As an intracanal medication, the chlorhexidine/CH combination had significantly more antibacterial activity than DW/CH combination.

Dental cobalt base alloys are biocompatible dental materials and have been widely used in dentistry. However, metals are bioinert and may not present bioactivity in human body. Bioactivity is the especial ability to interact with human body and make a bonding to soft and hard tissues. The aim of the present research was fabrication and bioactivity evaluation of novel cobalt alloy/ Fluorapatite nanocomposite (CoA/FaNC) with different amounts of Fluorapatite (FA) nanopowder. Co-Cr-Mo alloy (ASTM F75) powder was prepared and mixed in a planetary ball mill with different amounts of FA nanopowders (10, 15, 20% wt). Prepared composite powders were cold pressed and sintered at 1100°C for 4 h. X-ray diffraction (XRD), scanning electron microscopy and transition electron microscopy techniques were used for phase analysis, crystallite size determination of FA and also for phase analysis and evaluation of particle distribution of composites. Bioactivity behavior of prepared nanocomposites was evaluated in simulated body fluid (SBF) for 1 up to 28 days. Results showed that nucleus of apatite were formed on the surface of the prepared CoA/ FaNC during 1 up to 28 days immersion in the SBF solution. On the other hand, CoA/FaNC unlike Co-base alloy possessed bone-like apatite-formation ability. It was concluded that bioinert Co-Cr-Mo alloy could be successfully converted into bioactive nanocomposite by adding 10, 15, 20 wt% of FA nano particles.

Oral lichen planus (OLP) is a chronic mucocutaneous lesion with unknown etiology. Oral lichenoid lesions (OLL) comprise a family of lesions with different etiologies. Both lesions have similar clinical and histopathologic characteristics although their management is different. Differential diagnosis between OLP and OLL has always been a major challenge. In this prospective analytical study, the role of mast cells in pathogenesis of these lesions was investigated by evaluation of 52 patients with clinical and histopathological diagnosis of OLP (26 cases) and OLL (26 cases) based on WHO criteria, and by applying a more accessible staining methods, Hematoxylin and Eosin, toluidine blue (histochemistry) and Periodic Acid Schiff staining. In order to distinguish these two lesions, number of mast cells and thickness of epithelium and basement membrane were measured using light microscopy. Data were analyzed by SPSS software using t-test method (P<0.001). No significant difference was observed between the total numbers of mast cells of two groups (P=0.148), but a statistically significant difference was detected between degranulated mast cells in two groups (P<0.001). A significant difference was also observed between the thickness of epithelium in two groups (P<0.001), although no difference was seen between basement membrane thickness in these lesions. Number of degranulated mast cells in reticular layer of corium in lichenoid lesions was more than that of OLP. This implies that despite the increase in number of these cells, in both groups of diseases, the role of these cells has not been the same in pathogenesis of the diseases. Moreover, the epithelium thickness was lower in lesions of OLP compared to lesions of oral lichenoid, so this parameter may be a useful criterion together with other histopathological and clinical finding to discriminate these lesions. However, discrepancy of basement membrane thickness can not be a reliable criterion. Finally we suggest more accessible staining methods which are reliable for differentiation of these two lesions.

With the aim of developing methods that could increase the fracture resistance of structurally compromised endodontically treated teeth, this study was conducted to compare the effect of three esthetic post systems on the fracture resistance and failure modes of structurally compromised and normal roots. Forty five extracted and endodontically treated maxillary central teeth were assigned to 5 experimental groups (n=9). In two groups, the post spaces were prepared with the corresponding drills of the post systems to be restored with double taper light posts (DT. Light-Post) (group DT.N) and zirconia posts (Cosmopost) (group Zr.N). In other 3 groups thin wall canals were simulated to be restored with Double taper Light posts (DT.W), double taper Light posts and Ribbond fibers (DT+R.W) and Zirconia posts (Zr.W). After access cavity restoration and thermocycling, compressive load was applied and the fracture strength values and failure modes were evaluated. Data were analyzed using two-way ANOVA, Tukey and Fisher exact tests (P<0.05). The mean failure loads (N) were 678.56, 638.22, 732.44, 603.44 and 573.67 for groups DT.N, Zr.N, DT.W, DT+R.W and Zr.w respectively. Group DT+R.W exhibited significantly higher resistance to fracture compared to groups Zr.N, DT.W and Zr.w (P<0.05). A significant difference was detected between groups DT.N and Zr.W (P=0.027). Zirconia posts showed significantly higher root fracture compared to fiber posts (P=0.004). The structurally compromised teeth restored with double taper light posts and Ribbond fibers showed the most fracture resistance and their strengths were comparable to those of normal roots restored with double taper light posts. More desirable fracture patterns were observed in teeth restored with fiber posts.

Solid ameloblastoma (SAB) is an invasive tumor which infiltrates adjacent normal tissues. Adenomatoid odontogenic tumor is a noninvasive tumor and never infiltrates surrounding normal tissues. The purpose of this study was to determine the biological behavior of these two epithelial odontogenic neoplasm by detecting Ki-67 and Bcl-2, which are mitotic and anti apoptotic markers respectively. In this analytical retrospective study, 16 samples of SAB and 16 samples of adenomatoid odontogenic tumor were selected. The samples were deparafinized and antigens were retrieved. Immunohistochemistry technique was applied for evaluation of these two markers. Monoclonal antibodies MIB1 and Bcl-2 were used to detect Ki-67 and Bcl-2 protein respectively, then the labeling index (LI) was calculated for both markers according to cellular staining. Data were analyzed by “t” test, (P<0.05). The mean values of LI for Ki-67 in SAB and Adenomatiod odontogenic tumor (AOT) were 4 and 1% respectively and for Bcl-2 in SAB and AOT were 63 and 26% respectively. The indices of both markers were higher in SAB compared to AOT (P<0.05). Higher percentage of these two markers in SAB compared to AOT confirms the aggressive behavior of SAB and the hamartomatosis behavior of AOT.

The prevalence of denture stomatitis has been shown to vary from 15 to 65% in complete denture wearers. Satureja hortensis L. has been considered to have antinociceptive, antiinflammatory, antifungal and antimicrobial activities in vitro and exhibits strong inhibitory effect on the growth of periodontal bacteria. The aim of this study was to evaluate the efficacy of a 1% gel formulation of S. hortensis essential oil for the treatment of denture stomatitis. A randomized, controlled clinical trial study was conducted on 80 patients (mean age 62.91±7.34) in two parallel groups treated either with S. hortensis essential oil 1% gel or placebo applied two times daily for two weeks. Denture stomatitis was diagnosed by clinical examination and paraclinical confirmation with sampling the palatal mucosa for Candida albicans. Data were analyzed using Chi-squared or Student’s t tests. The erythematous lesions of palatal area were significantly reduced (P<0.0001) in the treatment group who applied 1% topical gel of S. hortensis essential oil and Candida colonies count were reduced significantly (P=0.001). Topical application of the essential oil of S. hortensis could be considered as an effective agent for the treatment of denture stomatitis.

Socket preservation after tooth extraction is one of the indications of bone grafting to enhance preorthodontic condition. The aim of this study is to determine the effects of socket preservation on the immediate tooth movement, alveolar ridge height preservation and orthodontic root resorption. In a split-mouth technique, twelve sites in three dogs were investigated as an experimental study. Crushed demineralized freeze-dried bone allograft (DFDBA) (CenoBone®) was used as the graft material. The defects were made by the extraction of 3rd premolar. On one side of each jaw, the defects were preserved by DFDBA and defects of the other side left opened as the control group. Simultaneously the teeth adjacent to the defects were pulled together by a NiTi coil spring. After eight weeks, the amount of (OTM), alveolar height, and root resorption were measured. Analysis of variance was used for purpose of comparison. There was a slight increase in OTM at grafted sites as they were compared to the control sites (P<0.05). Also a significant bone resorption in control site and successful socket preservation in experimental site were observed. Reduction of root resorption at the augmented site was significant compared to the normal healing site (P<0.05). Using socket preservation, tooth movement can be immediately started without waiting for the healing of the recipient site. This can provide some advantages like enhanced rate of OTM, its approved effects on ridge preservation that reduces the chance of dehiscence and the reduction of root resorption.

Mental illness is associated with physical health. Oral health affects people physically and psychologically and influences how they grow, enjoy life, look, speak, chew, taste food and socialize. Oral health may have lower priority in the context of mental illness and these diverse and changing client group experiences similar oral and dental problems. To assess oral health problems in psychiatric patients. This cross-sectional study included 133 patients attending the psychiatric outpatient department (OPD) as the study group and 133 patients attending the general OPD of the same hospital as the control group. Both groups were examined for oral health status. Mean age of the study group was 40.2 years, 66.17% were males, 66.17% were married and 83.67% belonged to middle or lower class. 39.8% of patients had mental illness for 1-5 years, 88% were self sufficient and 34.6% had healthy oral practices. These results are very much comparable with the control group. Mean decayed missed filled teeth (DMFT) score (2.10) and mean oral hygiene index-simplex (OHI-S) score (3.6) increased with age. Difference in DMFT score with age was not statistically significant (P>0.5) while it was highly significant for OHI-S score (P<0.0001). Periodontal condition worsened as age increased, suggested by community periodontal index. Only 26.7% of patients had healthy gingiva in the age group 20-50 years while it was zero for 50 years and above. This difference is statistically significant (P<0.001).

When an implant is exposed to oral cavity, its surface gets colonized by microorganisms. The aim of this study is to comparatively assess the microbiological parameters in sulci around the teeth and the crowns supported by dental implants. In this prospective, cross-sectional study, 34 partially edentulous patients aged between 40 and 50 years with total 50 anterior maxillary single implants with cemented crowns (depth of sulci <4 mm) and 34 similar teeth in the same jaw of the same patients were included. Excluded were the patients with compromised systemic and periodontal health and smoking habits. None of the patients had used any antimicrobial mouthwashes during at least two weeks before the study. All of the implants (ITI) were at least 6 months in place covered by definitive prostheses. Samples of gingival sulci were taken around teeth with paper cone and transported to Stuart transport medium. Samples were cultured and examined by a dark field microscope and eight laboratory tests were performed to determine the micro-organisms The data were evaluated statistically using Chi-square test (α=0.05). Six anerobic bacteria found in teeth and implants sulci were Gram-positive cocci, Gramnegative cocci, Prevotella, Porphyromonas gingivalis, Bacteroid Fragilis and Fusobacterium. Gram-positive cocci and Gram-negative cocci had maximum and minimum percentage frequency in the two groups, respectively. There were no significant differences between the two groups (P value >0.05). The present study indicated that microflora in implant sulci is similar to the tooth sulci, when the depth of sulci is normal (<4 mm). As a result, implants’ susceptibility to inflammation is the same as teeth.

This study was designed to evaluate the correlation between subjective data obtained from a questionnaire and clinical examination among students in Shiraz university of medical sciences. In this cross-sectional prospective study, the samples consisted of 200 subjects, with equal distribution between males and females. Subjects’ ages ranged from 18 to 30 years (24.07±2.93). A functional evaluation was performed using the Helkimo clinical dysfunction (Di) and anamnestic (Ai) indices. Data were evaluated by the Chi-square test between gender and clinical dysfunction index (Di) and correlation coefficient between Di and Ai (the level of significance was set at P<0.05). Among the total study population, 30% reported mild symptoms (Ai I) while 2% had severe (Ai II). In the clinical examination, 71% showed some degree of dysfunction. These degrees were as follows: 50% were classified as mild (Di I), 13% moderate (Di II) and 8% severe signs and symptoms (Di III). With respect to gender, women (80%) were more affected than men (62%). A significant relationship was found between gender and the occurrence of temporomandibular disorder (TMD) (P<0.05). The correlation coefficient (r) between the reported symptoms (Ai) and recorded signs (Di) was 0.53. There were positive correlation coefficient between Di and Ai. They were statistically significant (P<0.001). A high prevalence of signs and symptoms of TMD among students in Shiraz University of Medical Sciences was seen, which was greater in women. Despite suffering from TMD, students were not aware of their disorders.

This case report presents a combination of surgical and prosthetic solutions applied to a case of oral implant rehabilitation in post-oncologic reconstructed mandible. Bone resection due to surgical treatment of large mandibular neoplasm can cause long-span defects. Currently, mandibular fibula free flap graft is widely considered as a reliable technique for restoring this kind of defect. It restores the continuity of removed segment and re-establishes the contour of the lower jaw. However, the limited height of grafted fibula does not allow the insertion of regular length implants, therefore favouring vertical distraction osteogenesis as an important treatment choice. This report presents a patient affected by extensive mandibular ameloblastoma who underwent surgical reconstruction by fibula free flap because of partial mandibular resection. Guided distraction osteoneogenesis technique was applied to grafted bone, in order to obtain adequate bone height and to realize a prosthetically guided placement of 8 fixtures. After osseointegration, the patient was rehabilitated with a full arch, screw-retained prosthetic restoration. At five-years follow up, excellent integration of grafted tissue, steady levels of bone around the fixtures and healthy peri-implant tissues were reported.

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign, but locally infiltrating odontogenic neoplasm. It accounts for less than 1% of all odontogenic tumors. This is a case report of recurrent CEOT in the maxilla. A 35-year-old patient reported after three years of surgical excision of the lesion, with a recurrence. It is of particular concern because of its anatomic location in the maxilla. Maxillary tumors tend to be more aggressive and rapidly spreading and may involve the surrounding vital structures. Adequate resection of the lesion with disease-free surgical margins and long-term follow-up is recommended.