Journal of Dental Medicine
Year:2009 | Volume:22 | Issue:1 (58)|Papers Count:12

It is quite often for general practitioners who want to use implants in their routine treatments to face with the problem of unfamiliar radiographic techniques commonly prescribed in modern implantology. These types of radiograph, which could show the jaws in multiple aspects, are not routinely used by general practitioners. However, for sophisticated very delicate treatment options like implantology, the main problem is that "a metal object want to be placed in an undercut-full and zigzag area like bone", and the so called plain radiographs cannot be used for this purposes without difficulty. In this literature review, based on the data of the most powerful databases including COCHRANE and PUBMED, the necessity of using cross-sectional techniques in pre-implant treatment discussed in detail.

Background and Aim: Debonding is the most common failure type of fiber posts. This in vitro study aimed to evaluate the bond strength of 3 different fiber posts cemented with a resin luting agent in three regions of prepared post spaces after being subjected to termocycling.Materials and Methods Thirty six mandibular first premolars were sectioned at the cemento-enamel junction and were treated endodontically. After one week the post spaces were prepared and roots were divided into 3 groups of 12 specimens according to the post types (D.T.Composipost, D.T.White, D.T.Light). Sealbond Cement Dual II was used in all groups. One day after cementation, specimens were subjected to 3500 thermal cycles (5°C/55°C). Each root was then embedded in acrylic resin and sectioned perpendicular to long axis. Three 1-mm tick segments from apical, middle and cervical thirds were prepared. Push out test was performed. Data were analyzed with 2-way ANOVA (P<0.05). All root segments and dislodged posts were observed with stereomicroscope to figure out their failure modes.Results: The post type had no significant effect on bond strength (p=0.08). However bond strength at the coronl segment was higher than the other segments (p=0.005). Mixed mode was the mostly occurred failure mode with D.T.Composipost and D.T.Light but with D.T.White, the mostly occurred failure mode was adhesive between the post and cement.Conclusion: Different fiber posts have relatively similar bond strength to root dentin, bond strength at the coronl segment was higher than the other segments.

Background and Aim: Since the clinical studies conducted to explore the effect of bonding agents on the success of fissure sealant are limited in number, the present study was conducted to compare the effects of two bonding agents on the success of fissure sealant of the saliva- contaminated teeth.Materials and Methods: In this study, 63 teeth of 35 students aged 6-8 with healthy and newly-erupted upper jaw molar teeth, were selected and divided into two groups. In one group, single-bond and In the other, SE bond were used. As the teeth were newly erupted and the distopalatal area being in contact with the gingival sulcus and this fact that, this area was impossible to isolate, the distal sulcus of the contaminated teeth and the mesial area capable of adequate isolation were assumed isolated. For each group, after etching, the teeth on one side were treated with a sealant and the teeth on the other side were first bonded and then treated with the sealant. Hence, four groups were formed: bonded/isolated, bonded/contaminated, controlled/isolated and controlled/contaminated for any bonding agent. The results of the treatment were assessed in terms of the success and failure and then analyzed using Mc Nemar, and Chi-square tests and Cochran.Results: The results of the study indicated that:1. Saliva contamination caused a significant increase in sealant failures (p<0.05).2. Use of the two bonding agents significantly increased the success of the sealant (p<0.05).3. Use of the two bonding agents significantly increased the success of the fissure sealant on the saliva-contaminated teeth, even more than when the teeth had been isolated and with only fissure sealant(p<0.05). 4. For the contaminated enamel, the results of SE bond were better than those of the single bond (p<0.05). However, in isolated condition the results of using single bond were better (p<0.05).Conclusion: The results of the study supported the use of these two bonding agents in the treatment of fissure sealants under both isolated and contaminated conditions. Further, more SE bond seemed to be less sensitive to saliva contamination.

Background and Aim: Researches have shown that bacteria play the main role in development of pulpal and periapical diseases. Chemo-mechanical cleaning of infected root-canal system can not remove all of the microorganisms. Thus interappointment medicaments are necessary to aid this goal. Calcium hydroxide is one of the most useful medicaments in root canal therapy, but this medicament can not eliminated all of the bacteria in root canal system. Carvacrol is an edible plant extract that has antimicrobial and anti-inflammatory effects. If this extract is effective against endodontic bacteria, it can be used as an root canal medicament.Materials and Methods: In this experimental study, Initially, MIC and MBC of carvacrol detected with Macro broth dilution method and determined as 0.3% and 0.6%, respectively. After that, 30 single root and single canal extracted human teeth were used in this study. The number of specimens determined in a pilot study on 4 extracted teeth. After preparation to apical size #30 with hand and rotary instruments, teeth were randomly divided into two experimental and two control groups. After culturing Enterococcus faecalis in prepared canals, we used emulsion of 0.6% carvacrol and calcium hydroxide in two A and B experimental groups for 7 days as the intracanal medicament. Microbial samples obtained before and after experiment. Then, canals with negative culture selected to obtain dentinal shaving to culture. Data obtained from microbiological samples analyzed with kruskal-wallis and Bonferroni tests.Results: Results of this study showed that emulsion of 0.6% carvacrol has no significant difference with calcium hydroxide in elimination enterococcus faecalis after 7 days dressing (p>0.05).Conclusion: Carvacrol can be used as an intrappointment intracanal medicament.

Background and Aim: Extent of polymerization (Ep) is the rate at which methacrylate C=C bonds are converted to aliphatic C-C bonds. The higher the Ep value, the better the polymerization of the polymer. If the polymer dose not polymerize sufficiently, it could have destructive effects e.g. releasing monomer, initiator, free radical or insufficient polymerization of hybrid layer. Therefore, measuring the Ep value is very important. Light-emitting diodes (LEDs) are becoming increasingly popular in dental practice as they have a long life expectancy. LEDs do not generate infrared wavelength, and have a constant light output. Therefore, comparison of LED and Quartz tungsten halogen (QTH) from the point of Ep is important. Differential Scanning Calorimetry (DSC) is a proper tool for determining the Ep value, monitoring the process of reaction and reaction kinetics. The aim of this study was to measure the Ep value of a dental bonding containing camphorquinone/amine photoinitiator which were cured by LED and QTH using DSC.Materials and Methods: In this experimental study, 2.5 mg of bonding material were placed in DSC aluminum pans. Two different light cures, LED & QTH (Coltene Company Coltolux ®75 LED Curing Light), were used in this study. The light guide was positioned at a distance of 9mm from the base of the sample chamber. Each sample was photopolymerized for 30 seconds, and the DSC curves were obtained after 100 seconds from initiation of photopolimerization of each sample, at both 23°C and 37°C. The heat of photopolymerization (DH) was calculated from the area under the peak of the differential temperature curve. Five samples were used for each condition. The data was analyzed by two-way ANOVA.Results: There was highly significant difference between two temperatures in the experimental bonding (pvalue<0.001). Representative DSC curves showed the same kinetic behavior for LED and QTH.Conclusion: The results revealed that the Ep generated by high power density QTH was the same as that of produced by second generation of LED.

Background and Aim: A key factor in restoring the endodontically treated teeth is ferrule preparation. When the ferrule is absent, occlusal loads may cause the post or root to fracture. The purpose of this in vitro study was to evaluate the effect of ferrule preparation on fatigue resistance of teeth restored with quartz-fiber posts.Materials and Methods: Twenty single-rooted lower premolars having similar dimentions were randomly devided into two groups of 10. In control group the teeth were prepared with 3-mm of remaining coronal tooth structure and in test group teeth were prepared with 1-mm of remaining coronal tooth structure. The teeth were endodontically treated. 9-mm long Post holes were prepared, and D.T. light quartz-fiber(RTD,France) posts were cemented with Panavia F2(Kuraray,Japan).Then the core build up was done with Bisco core build up composite(Bisco,USA) and full metal crowns were cemented with Zinc phosphate(Harvard cement, Germany). All specimens were mounted in acrylic resin blocks and intermittently loaded (180 N) at an angulation of 45- degree to the long axis of the teeth at a frequency of 4 loads per second, until failure occurred.Results: There was significant difference between the loads cycles of two groups studied. (p<0.0001).Conclusion: The results of this study showed that an increased amount of coronal dentin significantly increases the fracture resistance of teeth restored with quartz-fiber posts.

Background and Aim: At the end of fixed orthodontic treatment, enamel damages are affected by amount of adhesive remnants. Thus, determining the factors involve in the amount of adhesive remnants e.g. the types of resins and the methods used for debonding is of necessity. The aim of this study was to evaluate the effect of the composite resin type and debonding pliers on enamel surface by a new method in measuring the adhesive remnant.Materials and Methods: In this interventionally in-vitro study, 120 extracted human premolars were randomly divided into four groups of 30 each. The standard edgewise metal brackets were bonded on the teeth with two pastes self-cure composite "Concise" in the first and second groups, and with No-mix composite "Unite" in the third and fourth groups. the debonding was done by means of Lift off Debonding Instrument "LODI" (3M-Unitek), in first and third groups, and Bracket Removing Plier (Dentaurum), in the second and forth groups, respectively. After debonding, all teeth were evaluated with steriology software (stereolith version 1) for comparing the amount of adhesive remnants between the four groups. For data analysis, One-way ANOVA and independent t.test were used.Results: The fourth group showed the lowest adhesive on the enamel surface and the most on the bracket surface with significant differences with other three groups (p<0.01). Conclusion: The use of Dentaurum debonding plier with shear-peel force when used with the Unite adhesive (group 4), would decrease the adhesive remnants on the enamel surface.

Background and Aim: Today, one of the most important environmental issues is dental solid wastes which are of great importance because of the presence of hazardous, toxic and pathogen agents. In this survey, solid waste produced in Hamedan general dental offices is evaluated.Materials and Methods: In this descriptive study, from 104 general dental offices in Hamedan , 10 offices were selected in simple random way. From each offices, 3 sample at the end of successive working day (Sunday, Monday and Tuesday) were analyzed. Samples were manually sorted into different 74 components and measured by means of laboratory scale. Then, measured components were classified in the basis of characteristic and hazardous potential as well as material type.Results: Total annual waste produced in general dental offices in Hamadan is 14662.67 Kg (9315.45>95.0% Confidence Interval>20009.88). Production percentages of infectious, domestic type, chemical and pharmaceutical and toxic wastes were 51.93, 38.16, 9.47, 0.44 respectively. Main components of produced dental waste were 14 components that consist of more than 80 percents of total dental solid waste. So, waste reduction, separation and recycling plans in the offices must be concentrated on these main components.Conclusion: In order to dental waste proper management, it is suggested that in addition to educate dentists for waste reduction, separation and recycling in the offices, each section of dental waste(toxic,chemical and pharmaceutical, infectious and domestic type wastes) separately and according to related criteria should be managed.

Background and Aim: Dental pulp calcification may have the same pathogenesis as vascular calcifications. Pulp stones are calcified mass, which are commonly observed in usual dental radiographs. The purpose of this study was to evaluate the relationship between pulp stones and ischemic CVD.Materials and Methods: This was a cross-sectional descriptive-analytic study on 20-25-year-old patients who had at least 8 intact teeth and were referred to Afshar hospital for cardiovascular examinations. Relationship between vascular stenosis and dental pulp stone was explored.Results: Sixty one patients who had undergone angiography were studied. They included 32 male (52.5%) and 29 female (47.5%). 38 patients had at least one stenotic vessel (from one to three vessels) and the others (37.7%) showed normal angiographic findings. 73.8% (31 cases) of the patients with dental pulp stones suffered from coronary narrowing where as only 36.8% (7 cases) of the patients without dental pulp stones showed coronary vessels narrowing. Pulp stones were mostly seen in first and second Molar teeth.Conclusion: According to the results, we can state that oral and maxillofacial radiology is helpful in screening of cardiovascular diseases.

Background and Aim: It is necessary to assess health status for designing and programming about oral health behaviors. In this study the Effectiveness of Health Promotion Model in Predicting oral health among the Students of Islamic Azad University of Sabzevar was examined. Materials and Methods: This was a descriptive-analytic, cross-sectional study. A random (stratified) sample of 250 university students in Islamic Azad university of Sabzevar, participated in the study. Appropriate instruments were designed to measure the variables of interest based on health promotion model. Reliability and validity of the instruments were examined by a panel of experts and cronbach alpha (N=30, a=0.65-0.81) respectively. The data were analyzed by SPSS 11.5 Statistical Software using Spearman Coefficient, Path analysis based on regression and ANOVA. Results: The mean of oral health behaviors among students was moderate (19.17±3.91 out of total 36).Statistically significant differences were found in oral health behaviors and the model variables by parent education (P<0.05). The results showed that the model variables were related to oral health behaviors of the students (P<0.05).Self-efficacy, interpersonal influences, positive emotion, perceived barriers and commitment to plan of action as variables of HPM model explained 29% of oral health behaviors among subjects within which self-efficacy was the strongest predictor(b=0.252). Conclusion: Although the mean of oral health behaviors was moderate among the subjects, but it should be promoted because of their great importance on the individuals' health. It was concluded that the Health Promotion Model may be used as a framework for planning intervention programs in an attempt to improve the oral health behaviors of the university students.