Journal of Dental Medicine

A review of recent method for surface preparation of metal in resin- bonded bridges.Part II: Biomcchamica! and technical considerations

A. Azari

After approximately 40 years of experience in the field of resin - bonded restorations (R.B.R),these restorations arc one of the most controversial. During these years, many suggestions have been made for better performance and increasing durability of these restorations. The aims of this paper are:1 - Reviewing the literature for the so many factors involving the success or failure of R.B.R.2 - Introducing a new and simplified method for increasing the durability and /or relention of R.B.R.

Dental considerations in pregnant patient

S. khedmat

During the human gestation period, various systemic alterations occur in the mother secondary to endocrine changes. These changes, combined with the presence of the gravid uterus, result in conditions affecting the various systems of the mother which must be considered by the dentist.Fetal development is divided into three stages:1) The fertilization and implantation period 2) The embryonic period and 3) The fetal period.The second period characterized by organogenesis which taratogens may result in functional and morphogenic malformations.The ideal dental treatment schedule for the pregnant patient is twice during first trimester, at least once during second trimester and once during third trimester.The second trimester is an ideal time for performing dental treatment.Emergency problem should be alleviated immediately during pregnancy.Indicated medications should not be with held because of pregnancy but patients must be informed of benefits and risks.With careful attention to the special needs of the pregnant patient, the dentist can provide high quality dental care while minimizing potential risks to mother and fetus.Emphasis should be on preventive strategies and meticulous oral hygiene to manage common oral problems associated with pregnancy.

Craniofacial dysostosis and a case report include surgical treatment of a Crouzon syndrome

H. Mahmood Hashemi

The most important craniofacial dysostosis & syndromes are Crouzon, Apret, Pfeiffer.Carpenter Saether- Chotzen. The common characteristic is premature closure of cranial sutures, which result in Maxillofacial deformities. Perfect recognition and carefully evaluation are the most important points in their reconstruction surgery.Because the prevalence & surgical treatment of Crouzon syndrome is low, I present a case report include surgical treatment of a patient with crouzon which was a accomplished in Shariati Hospital.

Effect of light emission on polymerization of luting resins

Indirect esthetic restorations have recently gained popularity, and choosing suitable cement is an important concern in this regard. A wide variety of resin cements with different curing models:(chemical, light, dual), have been introduced to the profession, and among them the dual systems are claimed to be able to continue polymerization after stopping the light. In order to study and compare the polymerization process of different curing systems, this research was performed.The present study measured the degree of conversion (DC) of three types of resin cements: a self cured,a light cured and a dual cured cement. The samples were prepared as follows:1-The self cured samples were made according to the manufacturer.2-The light cured samples were exposed to the curing light for 60 seconds, through a 2 mm thick wafer
of porcelain.3- The dual cured samples were divided into 2 groups. The first was lighted similar to the light cured samples, and the second did not receive any light.The degree of polymerization was measured by FTIR at time levels of 5, 10,20,30,45,60 minutes and 24 hours post mixing. The infrared spectrum of the samples were recorded and degree of conversion were determined. The results demonstrated an increase in mean DC of all groups at post mixing time, but this was significant only in the lighted dual cured cement (PO.05). The light cure resin showed high DC at the base line time (5min). At the end of 60 minutes, the self cure resin had the most DC. The unlighted dual cement had a very low DC and didn't improve in polymerization during the post mixing controls.The lighted dual cement had a significant improve in curing at post mixing times, and it was significantly different from unlighted dual cement. So the dual cure cement needs to receive sufficient light energy to initiate the curing process and the chemical component of this cement could not improve the DC completely.After 24 hours migration of unpolymerized monomers, seams to decrease the DC at the surfaces and removing the most superficial layer, showed that the underlying parts, had improved DC. It seems that in order to be sure of what happens at the restoration-tooth interface, it is appropriate to use self cure cements with improved flow and film thickness.

Determination of tetracycline dose in treatment of advanced periodontitis

This study is for appointment the dose of systemic 4 groups of patients selected for this study.First group had sealling, root planing and planing and periodontal surgery and no drugs. Second group had sealling, root planing and periodontal surgery with 1 gr per day of tetracycline for two weeks and third group for 3 weeks and fourth group for 4 weeks.The fourth group was.the best clinical improvement. The indexes were PPD, CAL, PI, GI.

Evaluation of length of the root trunk in first and second molars in population of Tehran

The root trunk (RT) of molar teeth is important diagnostic parameter that has a key roll in diagnosis and treatment planning.The purpose of this study is presenting a normal index of RT in mandibular molar teeth in different buccal (B). distal (D), Lingual (Li) and mesial (M) entrances, and to compare them with each other.It is a case series study that 351 extracted molar teeth, after removal of soft tissue and debridement of calculus, evaluated with gauge (with accuracy 0.1 mm) According to our measurement:In maxilla: M-side: 3.88± 0.15 mm, B-side: 4.7± 1.7. D- side: 4.87± 0.13mm. So with P.value <0.05 M and D RT are longer than and M RT is shorter than D RT.In mandibule: B- side: 2.73± 0.11mm and L side: 4.03±- 0.13mm. So with P.value < 0.01 Li RT is longer than B RT.According to ochsenbine classification our studying teeth have medium to long RT. We prescribe for educating the crater therapy in periodontal surgery the emphasize must be focused on craters with medium and long RT.The shortness of RT in B-side of lower molars needed the most attention during osteoctomy in resective procedures. Because RT not depended to underlying factors such as age, social and economic situation,and for large amount of sample size in our study, the result could be extended in Tehran.

Comparing and studying crack formation during apical cavity preparation using ultrasonic instruments

One of the major goals of periradicular surgery is to create a good apical sea! at the apex. This is done by sectioning of 2 to 3mm from the apex, preparation of a class I cavity and filling with a biocompatible material.The purpose of this in vitro study was to determine whether ultrasonic units used for root end preparations could change the surface & structure of resected root ends, as competed to common methods of retropreparation. Eighty-five extracted single rooted teeth were divided into five similar groups. Then instrumented and filled with lateral condensation method. Then three millimeter of apex was resected, retropreparaiions in two groups were done with low speed handpiece and round V) ^ur and cavities in two other groups prepared with the highest power of dentspiay ultrasonic unit with TFI-10 tip and in one other group prepared with the highest power of neo sonic ultrasonic unit with diamond coated CT-1 retro tip.Following root resection and retropreparation the surface of resected root ends were examined for the presence of any cracks or structural changes on the surface of resected root ends with stereo microscope 50x.The results of this study showed thai high power settings of ultrasonic units can increase the potential of crack formation on resected root surfaces. In conclusion it is better to use low power setting of ultrasonic for retropreparation.

The Relationship between mouth breathing and nocturnal diurnal enuresis in children

Enuresis during childhood disturbs children both physically and emotionally. It reduces their self-confidence and so causes many personal and social problems.Different ways of treating this problem have been suggested and carried out, but none of them have been a total success. But one way is to change from mouth breathing to nose breathing.Enuresis in 6 Patient out often was totally cured and in three other patients who's mouth breathing all altered to mouth- nose breathing it was reduced, approximately to the extended of a half.One who's mouth breathing was not subject to any change enuresis was not remedied either.On the whole, it could be concluded that the conversion of mouth breathing to nose breathing would solve enuretic difficulties to a certain extend.

An Epidemiologic study of lichen planus and direct inimunofluorescent on staining on it's paraffin sections

Frequently, diagnosis of lichen planus as a relative common chronic inflammatory mucocutaneous disease, is difficult, therefor, direct Immunofluorescence (DIF) examination is recommended for definite diagnosis. In this study both an statistical analysis of files of oral and maxillofacial pathology department of Dentistry school and direct immunofluorescence examination using paraffin blocks with new method, were performed. According to analysis of 8026 cases, 262 (3.26%) cases were diagnosed as lichen planus most patients were in fourth decade of their life and most common affected region was buccal mucosa, (69.68%).
In direct immunofluorescence study of 14 cases (using firth's method) fibrinogen deposits in 6 cases and immunostaining of colloid bodies with various immunoglobulins (IgA, IgG, IgM), C3 and also fibrinogen (few values) in most of patients, were detected. In spite of the fact that density of staining was lower than routine method (using fresh-frozen tissue), except for fibrinogen immunostaining, these findings are compatible with previous studies. In spile of limitation of samples, this study suggests that using this technique needs more evaluation and this can be used for diagnosis purposes when fresh-frozen tissue is unavailable.