Journal of Islamic Dental Association of IRAN
Volume:16 Issue: 3, 2007

Gingival recession is a relatively prevalent gingival disorder which increases with age. The purpose of this study was to compare free gingival graft technique (with citric acid) with subepithelial connective tissue graft in the coverage of denuded root surfaces of ClI and ClII Miller. Ten systemically healthy patients with at least two bilateral recession defects of clI and clII Miller participated in this study. After oral hygiene instruction and reaching plaque index below 2% and gingival bleading index below 10%, patients entered surgical phase. For each patient,the recession was treated using free gingival graft with citric acid on one side (group A) and with subepithelial connective tissue (group B) on the other side randomly. Recession width (RW), recession depth (RD), the width of Keratinized tissue (KT), probing depth probing attachment level were measured before and three months after surgery. The results were statistically analyzed by Mann-Whitney test. Keratinized tissue increased significantly after both surgical treatments, however, no significant difference was found between the groups. Furthermore, decrease in RD and RW with subepithelial connective tissue graft technique was significantly more than that with free gingival graft. In agreement with the results of other studies, the present study shows subepithelial connective tissue graft as a more efficient technique for root coverage, as compared with free gingival graft.

Removal of unsupported enamel is one of Block's important principles in cavity preparation. The aim of this study was to determine the effect of bonding materials in the protection of unsupported enamel and sound tooth structure. In this sound,30 sound mandibular molars were selected. After cusp reduction, a 3mm depth occlusal cavity with walls consisting of pure unsupported enamel of 3mm height, was prepared. The samples were divided into two groups. In the first group, the cavities were filled by composite. In the second group, the cavities were filled like the first group and the unsupported enamel surfaces were then etched extending 2mm buccocclussally and enamel dentin bonding was applied. The surfaces were finally covered by composite and light cured. The compressive strength of both groups were evaluated by an instron machine. Date were subjected to t-student test for analysis. The mean required force to break unsupported enamel was 3440N/mm2 in the first group and 4213N/mm2 in the second group showing the effective role of etching and buccal coverage of enamel in the protection of remaining weak enamel. The findings of this study suggest that the application of adhesives and coverage of the buccal surfaces support the weak enamel and dentin walls.

Carious lesions are generally found by dentists, using bite wing(B.W) radiographs and according to the observed depth of lesions, the treatment plan is designed. Although this technique is presently the most accepted and common one, due to the use of new high speed films with broad density and high voltages, there are some errors in determining the depth of proximal carious lesions. The goal of this study was to compare dentin thickness under proximal caries in bitewing radiography and tooth structure. Twenty - five tooth samples, consisting of 20 proximal carious lesions, were selected. Prior to and after caries removal, B.W radiographs were taken. Then, radiographs were investigated by two specialists, (Radiology and Operative Dentistry) and dentin thickness under caries were measured using a probe. Each tooth was then sectioned occluso gingivally and the thickness of dentin under proximal caries, on B.W radiographs and tooth stucture were measured by computer. Five healthy teeth were used as controls and 2 bitewing radiographs, before and, after cavity preparation,were taken and dentin thickness were also measured. The data were subjected to t-test. Mean dentin thickness in tooth structure was % 57 of its mean thickness in bitewing. radiography, showing a %42 reduction. More care should be paid while applying bitewing standard technique and its interpretation. Clinical examinations should also be performed under ideal conditions.

Dentin hypersensitivity is a chronic complaint among adult patients. The goal of this study was to compare the durability of the application of two techniques, Nd: YAG laser and dentin bonding agents, in the elimination of hypresensitivity. Twenty - eight patients with 116 hypersensitive teeth, who referred to the Operative Dentistry Department, Faculty of Dentistry, Tehran University of Medical Sciences, were,enrolled in this clinical trial. The left lower and upper teeth received Nd: YAG laser treatment (0.3 w,. 4 w, 0.5 w, 0.6 w, 0.7 w, 0.8 w, 0.9 and 1 w, each for 03 seconds). Then, dentin hypersensitivity was investigated applying forced air and in positive cases, laser treatment was repeated. The hypersensitive teeth, on the right side, were firstly etched with %37 phosphoric acid. For 5 seconds, washed with water and airdried. Then a single layer of excite adhesive was applied and after30-second airdrying, the teeth were light. cured for 20 seconds. In case of hypersensitivity, this technique was reapplied. In 3 and 6 months follow-ups, hypersensitivity was investigated and the data were analyzed using Mann-Whitney test. In 6-month follow-up, the success rate of dentin bondings was %62.7 where as that of laser was.%42 showing a statistically significant difference (<0.05). Although both techinques lead to the reduction or total elimination of dentin sensitivity, dentin bonding agents exert a more durable effect.

One of the current ptoblems in endodontic treatment is the establishment of optimal anesthesia on mandible. In this clinical study, two approved mandibular block technique were compared in the establishment of pulpal anesthesia. Inferior dental anesthesia via conevenional and Gow - Gates techniques were evaluated using onset of anesthesia, pain severity duriny injection, aspiration test, pulpal anesthesia (via ice test, cavity test and pain during entrance into pulp chamber) and pinprick test (inferior alveolar, long buccal nerves).58 patients requiring root canal rteatment of mandibular molars were divided into two groups. They were given injections of 1.8 ml of %2 lidocaine with adrenaline (1: 80,000). Results were analyzed using Mamm - Whitney and t-student tests. No significant diffetences were found between two techniques in ice test, cavity test, pain upon entrance to pulp chamber, pinprick test, aspiration test and injection better results about injection pain and aspiration test. Time required for lip and tongue anesthesia in conventional technique was less than Gow – Gates (p<0.001) although buccal nerve was anesthetized more in Gow - Gates Technique (P = 0.001). Although the aspiration test did not show a sigcificant difference, but the lack of positive aspitation case in Gow - Gates technique, in conparison with %10.7 in conventional technique seemed to be important. No significant difference in pulpal anesthesia between two techniques was shown,% 57.1 of patients had pain during entrance to pulp chamber in conventional technique comparing to %39.2 in Gow - Gates technique. The buccal nerve was anesthesized more in Gow - Gates tenchnique (%75) as compared with conventional one (%42.9), which was significantly different (p=0.01), but other branches (inferior alveolar and lingual nerves) were anesthesized equally in both applied techniques. On average, patients acquired lip and tongue numbness in 1.42 and 3.27 minutes, respectively in minutes was required in conventional method but more than 7 minutes was required in Gow-Gates technique. (p<0.001). Irrespective of the operator clinical experience, Gow-Gales technique appears to be more effective in pulpal anesthesia although more slowly yielded anesthesia, as compared with conventional method, is one of its disadvantages.

Trauma, as one of the most prevalent tooth accidents in all stages of life, has received a lot of attention. Increasing knowledge about trauma can reduce and prevent its harmful consequences as well as the related costs. The aim of this study was to evaluate treatment prognosis of anterior traumatized teeth among patients referred to endodontics and pediatrics of Shaheed Beheshti and Tehran dental faculties during 1995-2000. In this descriptive and exsisting data study, a written questionnaire was used for data collection. Files of patients with completed treatment, in endodontics and pediatrics departments of both dental faculties were investigated. The colleefed data were analyzed by SPSS software. 84% of the studied teeth were maxillary central teeth. The most prevalent etiology for trauma was falling down and the most prevalent type of fracture was that of enamel and dentin without pulpal involvement. The most reported treatment was pulpal and periapical treatment. traumatized anterior teeth, was acceptable. Treatment procedures conducted on the traumatized anterior teeth, was acceptable.

Myxoid histological pattern is of nonspecific features that is seen in most of benign and malignant lesions occupying a great mass of them. Thus, histopathologic diagnosis depends on a careful and precise investigation. The aim of this study was to differentiate between mucins in myxoid tissues through histochemical staining. Archives of three important educational pathology departments (Facutty of Dentistry of Tehran University, cancer institute of Imam Khomeini hospital and Amir alam hospital) were investigated and information on head and neck tumors with myxoid histopathologic pattern were worked out, then slides and paraffin embeded blocks were studied. Tissue slides of 5mm thickness were stained with PAS/Alcian blue technique and studied under light microscope. The notable standard was the predominant stain of mucin in histological field. The study of 41histologic slides countaining: malignant fibrous histocytoma (MFH)(n=4), Rhabdomyosarwma (n=6),Chondrosar coma (n=6), Schwannoma (n=7), Neurofibroma (n= 8), Pleomorphic adenoma (n=4) and Odontogenic myxoma (n=6), revealed that neurologic derived lesions and Rhabdomyo sarcoma and MFH had notable red field (neutral mucin nature) where as chondrosarcoma, pleomorphic adenoma and odontogenic myxoma had notable blue field (acidic mucin nature). Despite limited cases, the results showed that different nature of mucins in different lesions can be considered as a good criteria for differential diagnosis, however, more detailed studies are recommended.

Introduction of a material, that in blood contamination, can maintain marginal seal plays an important role in clinical success of a restoration. The aim of this study was to determine and compare microleakage rates of composite and compomer restorative materials, in blood contamination, with the application of Prompt L-Pop as an adhesive system. In this experimental study, One hundred and twenty ClV cavities, in dentino - enamal junction of buccal and lingual surfaces of extracted human sound molars, were prepared. After Prompt L-Pop application, the samples were divided in to 10 groups of 12 cavities Group Z1 was control Group Z2 was contaminated. Group Z3 was rinsed with water after contamination. Group Z4 was rinsed with water after contamination and Pronpt L-Pop was reused. GroupZ5. was similar to Z4 but it was rinsed with Naocl after contamination. The cavities were filled with composite (Z 520). The remaining five groups (F1 to F5), were just the same but filled with compomer (F 2000). After polishing and thremocycling (X 500) the microleakage rates of specimens were evaluated with dye penetration method. The data were statistically analyzed using Kruskal - Wallis and Mann - Whitney tests. Kruskal - Wallis test revealed significant differences among composite groups in gingival margins (p= 0.017). Mann - Whitney test showed more microleakage in group Z2 as compared with groups, Z1 Z4 and Z5 (P=0.005, P=0.015 and P=0.015, respectively) which was statistically significant. No significant differences were found, in microleakage rate, between composite andcompomer groups in occlusal and gingival margins (P= 0.348 and P=0.213,respectively). According to the results of this study, blood contamination could increase the microleakage of composite and Prompt L-Pop in gingival margins. In this condition rinsing with water and Naocl and Prompt L-Pop reapplication can decrease microleakage effectively.

Recognizing canal configuration is necessary for a correct endodontic therapy and lack of information about canal configuration leads to failure in therapy. Since one of the most effective factors in caral configuration is race, an in in vitro and in vivo study was conducted in the city of Isfahan. The aim of this study was to recognize different canal configurations of mandibular anterior teeth and compare the clinical and laboratory results. In the laboratory study (In vitro),314 mandibular anterior teeth were selected and then cleared. The cleared canine teeth were also studied by sectional method. The number of roots and their canals, according to the existing orifices, were recognized. In the clinical study (In vivo),415 radiographs of mandibular anterior teeth treated in graduate and under graduate departments of Isfahan University Faculty of Dentistry were selected and studied. Finally, the results of two methods were analyzed and compared. In the clearing (In vitro) method, out of 100 mandibular centrals with one root, canal configurations, based on weine classification, were type I (%69) type II (%27), type IV (%4) and type III was not observed. Out of 130 mandibular laterals with one root, canal configurations were type I(%58.43), type II (%13.59), and type IV (%0.98) and type III was not observed. Out of 111 mandibular canines, 2 of them had two toots and 109 had one root, canal configurations in this tooth were type I (%91), type II (%4.5), type III (%1.8) and type IV (%2.70). Canal configuration in this tooth by, sectional method was type I (%88.3) type II (%7.2), type III (%1.8) and type IV (%2.7). In the clinical (In vivo) method, out of 146 mandibular centrals with one root, canal configurations were type I(%78.68), type II (%10.95), and type III (%1.73), and type IV was not observed. Out of 115 mandibular laterals with one root, configurations in this tooth were type I, (%82.60) type II (%41.79) and type III (%2.61). Out of 154 mandibular canines, all of them had one root, canal configurations were type I (%95.45), type II (%2.60), type III (%1.30) and type IV (%0.65). The results of this study were different from those of other researches, which could be caused by factors such as race and method. Moreover, the clinical results were different from the laboratory ones, possibly resulting from more precise laboratory studies. Additionally, considering high percentage of two canals in lower anterior teeth, more attention for the detection of the second canal, is recommended.