Dental Research Journal
Volume:2 Issue: 1, Jan 2005

Background and aim
Recurrent aphthous stomatitis (RAS) is an oral mucous lesion in patients with no other signs of disease. Investigators have always notified the role of immune system especially humoral immunity in aphthous immunopathogenesis.The aim of this case-controlled study was to measure amount of serum immunoglobulins (A, G, M) and complement components (C3, C4) in patients with RAS and to evaluate any relation between differences in these factors and pathogenesis of RAS.
Methods and Materials
Imunoglobulins (A, G, M) and complement components (C3, C4) of 50 patients with RAS were measured by using single radial immunodiffusion technique (SRID T). The results were compared with immunoglobulins (A, G, M) and complement components (C3, C4) of 50 healthy people whom were similar in age and sex with the patients of case group.
Results
Results showed that the patients group had higher level of IgA and IgM while serum IgG was similar in both groups. The C3 was lower in aphthous patients while no significant difference waS found in amount of C4. The sex had no significant effect on serum level of measured factors.
Discussion
The resul.ts show that the humoral immunity reaction has an important role in immunopathogenesis of RAS. This humoral response might accure as a result of cellular immunity reaction.

Background and aim
The human teeth have different anatomical variations and treatment of each tooth is under the influence of its configuration. The root canal anatomy, not only in various teeth, but also in one tooth might be different. The important point is to understand the canal anatomy that is essential for root canal therapy. In various studies, different results have been reported from different regions of the world, additionally a number of studies have shown different trends in shape and number of roots and canals among different races. Since there is a lack of information about canal configuration in the city of Isfahan, therefore this study was done to determine the frequency of canal configuration in max-illary fIrst and second molars.
Methods and Materials
This study was descriptive, that was done on 160 extracted maxillary first and second molars, which were collected from clinics and private offices in the city of Isfahan. Pulp tissue was removed and canal system was stained with Indian ink, the teeth were decalcified with 10% nitric acid, dehydrated and cleared with methyl salicylate. Maxillary flfSt molars were addi-tionally cut in cross sections in three points of the root and canal configuration of teeth were evaluated.
Results
The examination of root canal systems of teeth was based on Weine classification. The majority of maxillary first and second molars had three separate roots. A variety of canal types were found in mesiobuccal (MB) roots of first and second molars. More than half of the MB roots of first molars(61 %) had two canals, whereas MB roots of second molars mostly had type I canals (76.38%)in the clearing method. The palatal and distobuccal canals mainly had type I canal configuration. In the sectional method more than half the MB roots of first molars had two canals (78.47%).
Discussion
In other countries many researches have been done using different methods about internal anatomy of teeth and the results are different from this study. It appears that the differences are caused by genetic factors and methods used. Also results of this study were different in types I and IV in MB roots in the two methods, this difference is probably due to better access and vis-ibility to canal in the sectional method.

Background and aim
Restorative dentistry searches the use of glass fiber-reinforced composite is just now experiencing rapid expansion in dentistry. This study compared of fracture strength a glass fiber-reinforced composite (GFRC) and a fiber-reinforced composite (FRC) as a framework for fabrication of resin-bonded fixed partial dentures (RBFPDs).
Methods and Materials
Twenty RBFPDs were made with GFRC (everStick) and FRC (Ribbond). The specimens were stored for 2 weeks at 37 1 C in distilled water, thermocycled (5-55C, x 2500) and statically loaded to fracture. The hounsfield testing machine measured fracture strength of the samples. Metal cone with tip 1 mm income vertically to central of labial surface of pontic with speed 1 mm/min. The force in Newtons was recorded at debonding of prothosis from abutment teeth and then SEM.
Results
The mean and standard deviation for fracture strength of GFRC RBFPDs were 440±75 and for FRC RBFPDs were 309±33. ANOVA showed that fracture strength between two groups were statistically significant (pv =0.000247). SEM examination revealed that debonding between the GFRC RBFPDs and the tooth and no debonding between the glass bundle and the composite.
Conclusion
On the basis of the results of this study, GFRC that can be used in the fabrication of 3-unit anterior FPDs.

Background and aim
This study evaluated influence of pH of storage media and storage time on cervical sealing performance of three different bonding systems. The microleakage of three bonding systems) Scotchbond Mulit-purpose, Perma Quik PQ1 and Clearfil SE bond (over 7 days, 30 days and 90 days was investigated.
Methods and Materials
Two hundred and seventy class V wedge shape cavities were prepared in sound human premolars with coronal margins in enamel and cervical margins in dentin / cementum. Bonding systems were applied strictly according to manufactures instructions. Cavities were restored by Z100 resin composite. After finishing and polishing, teeth were randomly divided according to the storage medium and storage time to 27 groups (n=10).Specimens were coated with nail varnish, immersed in silver nitrate for 4 hours and sectioned longitudinally. The extend leakage was measured and ranked using a 0-3 scale.
Results
Statistical analysis using Kruskal-wallis test revealed significantly higher leakage scores (p

Background and aim
Cross infection control is a great concern to which great attention should thus be paid. Infection control protocols in dental radiology are employed to reduce the potential for infectious disease transmission. The areas relevant to the exposure and processing of dental radiographs are not routinely associated with the spatter of blood or saliva; however, infectious disease transmission is still possible if we use contaminated equipment, supplies, film pockets or cassettes.This study aims at comparing the disinfectant efficacy of micro 10, sodium hypochlorite, betadine and savlon on the equipment of the radiology department.
Methods and Materials
For each solution, sampling was performed, before disinfection, on 27 sections of the radiology department. Experimental surfaces were then disinfected by the spray-wipe-spray method followed by resembling. The samples were subsequently cultured on bloody agar plates and the colonies were counted.
Results
The results of this research showed that the mean rank of turbidity degrees of culture media are respectively 76.74,68.96,59.48, 68.96 & 65.85 before disinfection with sodium hypochlorite, betadine, savlon, micro 10 and normal saline. They are respectively 60.74, 50.91, 67.06, 49.37 and 111.93 after disinfection.
The results of Kruskal-Wallis test showed that there is a significant difference between the turbidity degrees of culture media after disinfection with the five solutions (Pv

Background and aim
It has been established that success of the root canal treatment depends on the quality of root canal obturation. The aim of this study was to compare the apical sealing ability of three root canal sealers.
Methods and Materials
The apical sealing ability of root canal sealers AH26, AH Plus and zinc-oxide eugenol (ZOE) were tested on 100 single-rooted teeth. The coronal part of each tooth was removed about 2mm above the cementoenamal junction. Root canals were instrumented using the “Step-Back” technique using hand files and Gates Glidden drills and irrigated with 2.5% sodium hypochlorite. The teeth were divided into three groups of 30 teeth each and filled with test sealers and gutta-percha points by the cold lateral condensation technique. Ten teeth were used as control groups (five served as negative and five as positive controls). The teeth were immersed in 2% methylene blue for 3 days. The teeth were then longitudinally sectioned and evaluated for linear apical dye penetration.
Results
The differences in leakage among AH26 (2.08mm;SD 0.215), AH Plus (3.64mm;SD 0.182) and ZOE (5.41mm;SD 0.274) were statistically significant (P

Background and aim
This in vitro study compared the ability of horizontal pins and an adhesive resin cement to reinforce the facial cusp of endodontically treated maxillary premolars.
Methods and Materials
Seventy-two maxillary premolars were divided into six groups and mounted in acrylic blocks (n=12). In all of groups standardized endodontic treatment were completed. In groups 2-6 the palatal cusp were reduced, leaving the buccal cusp intact. In group 1 access cavity was filled with amalgam simply. The facial cusps of the teeth in other groups received one of the following reinforcements: Group 2- no reinforcement; Group 3- amalgam build up; Group 4- two horizontal dentinal pins; Group 5- Adhesive resin cement. Teeth in Group 6 were prepared for and restored with amalgam using two horizontal dentinal pins and adhesive resin cement. Then the lingual slope of the facial cusp of each specimen was loaded to failure using a compressive force. The mean fracture strengths for all groups were analyzed using statistical analysis. ( = 0.05). Fracture patterns and modes of failure were also evaluated.
Results
The mean fracture values for groups were 1429.58; 701.80, 1242.50, 1298.63, 1289.25, 1311.83 kgf respectively. With the exception of group 1 (positive control group), group 6 were more fracture resistant than all other groups, and there were not significant difference between that group with groups 1 and 3-5.
Discussion
The buccal cusp of endodontically treated maxillary premolars whether reinforced with a horizontal pins or adhesive resin cement were not significantly weaker than conservatively restore teeth.

Background and aim
"Recurrent Aphthous Stomatitis" is an ulcer that appears in the Oral mucosa in the form of painful and often recurrent ulcers. Its prevalence is 10 to 20 percents. And in some of the selected groups such as students, its prevalence is up to 50 percents. Its appearance in female is more than male. No single reason has been recognized for this disease. Some of sources have referred to the relation of this disease with stress. The purpose of this study was to survey the role of stress as one of the factors that create recurrent aphthous stomatitis
Methods and Materials
This is a case-control study, in this study 61 patients with aphthous stomatitis that had been referred to the oral medicine department and affiliated clinics were examined. 61 patients were selected from two sexes randomly. Control group was consisted of the siblings of the patients who had been referred and selected randomly. After patient justification, Diagnosis and attestation of the professor, the “Standard questionnaire for measuring stress” in the name of “Klementz & Raberts” was completed by the patients and control group.The information was analyzed statistically through T-Test.
Discussion
The obtained information indicated that the average of stress mark in case and control group was 384 and 249 respectively. T-Test indicated that there was a significant difference between stress mark in two case an control groups (P