Journal of Dentistry, Shiraz University of Medical Sciences
Volume:4 Issue: 2, 2003

Pulpotomy is among the most common methods for the treatment of the primary tooth pulps and the drug of choice in that method is formocresol. Our main objective of doing pulpotomy with formocresol is to maintain the tooth in an asymptomatic condition until normal resorption till exfoliation occurs. The purpose of this study was to examine the success rate of a two-visit pulpotomy with formocresol in vital primary molar teeth, after at least two years. The population under study consisted of 36 children, 5-10 years-old, referring to the special clinic of Shiraz School of Dentistry, all of whom were treated by the project executor.

72 pulpotomized teeth in the mouths of 36 children in the 5-10 years age group (40 boys and 32 girls) who were treated from April 1992 up to June 2001 were examined and they were evaluated clinically and radiographically from March up to June 2003.

Among 72 teeth under the study, some were excluded from the study during the process due to various reasons, so that in the clinical study, 70 teeth and in the radiographic study, 55 teeth were studied. As a whole, considering the mean time period of 30 months after treatment, the clinical success rate of 94.3% and the radiographic success rate of 85.5% were obtained (Table and Graph no.1,2).

As in different studies in which the success rate of pulpotomy treatment with formocresol is reported to be between 70 to 90%, the success rate in the current study was in the same range, though we have not been strict in choosing the teeth for treatment, an issue which probably has had a significant role in reducing the success rate of treatment. In numerous other studies, the highest rate of failure is related to internal root resorption, which includes about 85.5% of the total unsuccessful treatment in this study and 12.5% of failure rate belonging to external pathologic root resorption.

This research was conducted in the academic year 2002-2003 in the Department of Prosthodontics of School of Dentistry, Shiraz University of Medical Sciences to investigate patients post complications after delivery of R.P.D.

50 Patients who were psychologically healthy and withoutsystemic diseases were selected. The dentures were made and delivered by sixth yeardental students. They were evaluated twice using questionaires one day and one weekafter the delivery of their dentures. Responses of patients to the proposed questions were evaluated.

Statistical analysis of the data showed that denture soreness on residual ridge and vestibule was maximum (72%), which was reduced to 12% after one week. Lack of retention in centric and eccentric was 44%, which was reduced to 15% one week later. Gag reflex and speaking inability was reduced from 44% to 4% in one week. Herpis and apthus lesion were low.

It is recommended that more precise attention be given to impression stages and occlusion adjustment while making R.P.D.

Cement space is necessary for seatabillity and fittness of cast crowns, but can affect crown’s retention. In this study the interrelationship between them was investigated via die spacing.

For evaluating the effect of die spacing (cement space) on crown retention after cementation, 50 similar machined metallic dies were prepared and divided into five groups and coated with 0.2,4,6,8 layers of paint-on standard die spacer, respectively. Cast crowns were fabricated on the dies using base metal alloy’s, and then cemented with zinc phosphate cement under a constant load of 5 kg for 10 minutes. The samples were started in distilled water for 48 hours. Then the force required to remove each crown from the die was measured with instron.

Statistical analysis revealed a significant increase in the force required (crown retention) by adding layers of die spacer (p<0.05).

Because retention didn’t show any significant increase with more than 4 layers of die spacer, so optimum thickness of die spacer (or cement space produced) is suggested to be 4 layers equal to 40 microns.

There has long been an understanding that a certain maxillary –tomandibular tooth size relationship is important for proper occlusal relationships. Thepurposes of this study were to compare the Bolton ratio’s (Anterior and total) of skeletaland dental Cl I individuals in Shiraz and to assess the sizes of teeth and correlationcoefficient between similar teeth in the left and right sides and in the upper and lowerjaws in males and females.

The data were derived from collected post treatment casts of 50 class I skeletal and dental patients (29 females, 21males) treated orthodontically by noneextraction method. Measurements of the mesio-distal size (M-D) were performed on the models and Bolton ratios were calculated. Then statistical analysis was done to compare the tooth size and also Bolton ratios.

The teeth size correlation was calculated 0.9 between the right and left sides of the jaws and 0.8 between the similar teeth in the upper and lower jaws. The mean value and standard deviation (SD) for the anterior and total ratios were: %77.2 + 2.66, %90.6 + 2, whit no significant difference with Bolton’s ratios, but the range of ratios was greater respectively in our sample. The ratios were also compared among males and females, but no sex dimorphism was seen.

1- The upper maxillary incisors had the most variable M-D sizes. 2- There was no sex difference in the M-D tooth size of this sample. 3- Although the values of ratios were not significantly different from those of Bolton’s value, the greater range and SD of the ratios showed the different distribution patterns of the ratios in our study.Therefore a careful analysis of interarch relationship should always be induced in diagnostic procedures.

Today, the relationship between the classification of F.I.*1 and some factors such as, the amount of horizontal and vertical bone loss, the pattern of the interradicular bone and root morphology is revealed. Recently, some attention has been paid to the importance of the length of R.T.*2 in identifying the diagnosis and prognosis of F.I. So, the length of R.T. may be included in some F.I. classifications in the future. In the present study, the R.T. length of the first and second maxillary and mandibular molarteeth was measured and the prevalence of short, long and medium sized root trunks aswell as type A, B, and C was estimated.

The sample consisted of 322 first and second extractedmaxillary and mandibular molar teeth because of various reasons in Shiraz. All of theteeth were intact from C.E.J. up to the apex of the root without any fracture, filling,restoration or caries. At first, a series of reference points including C.E.J. top of thefornix on the furcation area and apex of the root were marked. The distance betweenC.E.J., and the furcation area was measured in order to determine the root trunk length,while the distance between C.E.J and the apex was measured to determine the total root length. The study was single blind and all the measurements were made by the sameoperator. Different types of R.T. were identified based on the root trunk length to thetotal root length ratio on individual aspects.

The R.T. length of buccal and mesial aspects was markedly more than that of the distal aspect in maxillary molars. Although a major proportion of RTs of all of the teeth, was included in the medium sized group, the buccal aspect of the mandibular first molars had a shorter vertical length than the others.

The results revealed that the incidence of type B, R.T. in all aspects of both maxillary and mandibular molars were more than type A and C. More incidence of F.I. on the buccal side of the mandibular first molars is related to shorter R.T. of this area than the others. Further investigations are suggested about the relationship between the amount of periodontal attachment loss and the type of the R.T.

Serial extraction (SE) or guidance of eruption is reversed for treatment of severe tooth-size arch -size discrepancies, where space deficiency is more than 10 mm. It seems necessary to have sufficient information on the types of malocclusion and hereditary crowding. Of course, most cases of 5 to 9 mm space deficiency need serial extraction after through diagnosis and treatment planning in order to preserve facial esthetics and the integrity of the supporting soft tissue. It is necessary to have a through understanding of the growth and development with all its ramifications, and it is also essential to be aware of the occlusion of dentition, with its relationship to the craniofacial structures and its function. This study was performed to categorize the malocclusion to types and to assess the need for hereditary crowding and serial extraction among 7-9 year old children.

After providing questionnaires, 3776 children with an age range of 7-9 years were randomly examined for occlusion condition and crowding.

Different malocclusions were obtained to be as follows: 30.5% normal class I occlusion; 47.4% Cl.I malocclusion; 13.7% Cl.II Div.1 (male/ female ratio was 3:2); 1% Cl.II Div.2 malocclusion (male/ female ratio was 3:1) and 2.1% Cl.III malocclusion.

Among the students, 47.9% had crowding problems and 14.7% had class I malocclusion which were observed in girls to be 17.3% as compared to boys (12.1%).

Using fissure sealants on the occlusal surfaces of primary and permanent molar teeth is one of the most effective methods in the prevention of caries in children. Because of the certain problems in children such as lack or weakness of cooperation with the dentist, lack of patience in long duration treatments and difficulty in the control of secretary saliva, finding the shortest etching time effective in the retention of fissure sealants and reducing the duration of treatment is an important factor in the success rate of this preventive method.

The research was conducted on 360 molar teeth (200 second primary molars and 160 first permanent molars) in the Shirazian 6-10 year-olds students. After selection of the appropriate teeth not having any decay or enamel hypoplasia or resorption, and after appropriate isolation, the etching procedure in 30, 60, 90 and 120 seconds was done using 37% solution of phosphoric acid. After irrigation for about 30 seconds and drying the tooth for about 20 seconds the sealants is put on the occlusal surfaces of the teeth were and polymerized by the light cure device for 20 seconds. After 3,6 and 9 months follow-up periods, the retention of the fissure sealant material on the both groups of molar teeth was evaluated. The effect of etching time on the retention of this material on the occlusal fissures of the molar teeth was evaluated and the retention of sealants on the primary and permanent molars was then compared.

This study showed that, the most appropriate etching time for both the second primary and first permanent molars was 30 seconds, and the longer the etching time, thelower was the retention of sealant on the mentioned teeth. The first permanent molars were more appropriate for sealant therapy in comparison with the second primary molars and the sealant material is more retentive in this group of teeth.

The most appropriate etching time for sealant therapy of the second primary as well as the first permanent molar teeth is 30 seconds. The retention of sealants in primary second molars is somewhat lower than permanent first molar teeth and all the important factors in different steps of sealant therapy more showed be considered precisely for improving the success rate of this procedure in primary molar teeth.

Several studies on different aspects of TMD have been conducted in both complete edentulous patients and in dentate individuals. But there are few studies in partial edentulous patients with more occlusal destruction. In addition, there are some controversies about the role of supportive natural teeth as an etiologic or perpetuating factor in TMD. The aim of this epidemiologic survey was to find the relationship between TMD and dental condition in partial edentulous patients. One hundred forty subjects were selected for this investigation. The degree of dental invalidity was classified by Eichner’s index. The severity of clinical signs and symtomes of TMD was assessed by Helkimo’s clinical Index. Finally, for each Eichner’s classification, Dysfunction index (Di) was evaluated and then compared. The distribution of the patients according to the number of supportive zones by natural teeth was as follow: group A: Dio 60%, DiI 34%, DiII 4%, Group B1: Dio 29%, DiI 51%, DiII 20%, Group B2: DiI 51%, DiII 41%, DiIII 8%, Group C: Dio 19%, DiI37%, DiII 31%, DiIII 13%. A significant relationship was found between the reduced supporting zones by natural teeth and dysfunction index (p<0.001), i.e. group A had the lowest and group C had the highest Dysfunction Index (Di).

The relation between periodontitis and cardiovascular diseases has been of interest inrecent years. Cardiovascular diseases in the developed countries account for 50% of themortality rate and are the principal causes of death. Periodontitis, one of the mostcommon diseases of human, is an infectious condition that can result in inflammatorydestruction of the peridontal ligament and alveolar bone. Periodontitis and atherosclerosishave complex etiologies like genetics and gender, and they potentially share many riskfactors, the most significant of which may be smoking. A number of studies have shown asignificant relationship between periodontitis and cardiovascular diseases, but the needfor further studies of new definitions of relationship between them especially in womenseems to be demanded