Journal of Dental Medicine

E. Yasini

Normal 0 false false false EN-US X-NONE AR-SA Class-Ionomer cements include calcium aluminosilicate glass and fluid component of acrylic acid. An important property of these cements is chemical adhesion to enamel and dentin and releasing anti-caries fluride. Clinical use of these cements involves filling erosions without cavity preparation, preventive dentistry and filling class V and llI cavities. In addition, another desirable property of these cements is their biocompatibility with tissues and dental pulp.

Pontics

R. Amirlo

Normal 0 false false false EN-US X-NONE AR-SA Failure or success of a bridge is grounded on pontic design. Pontic is defined as the part of a fixed prosthesis that replaces the extracted teeth. According to the importance of many factors such as contour, durability, strength, color, esthetics hygienic design in the pontics, this article has fully discussed on this issues.

Analyzing Physiologic occlusion

M. Emamie

Generally speaking, when preserving and restoring the gnathostomatic system the dentist controls tooth morphology to insure proper distribution of stress. So, we restore a portion of a tooth or all the teeth in such a manner as to subject the associated parts of the system to the least stress. We evaluate our diagnosis and control it in our treatment. The treatment should be based on the scientific method. We create optimal occlusion or a desirable functional state of the masticatory system. Many persons with occlusal imperfections will not have symptoms of functional disorders. This is the psychological adaptive capacity of the neuromuscular system, teeth, dental arches, and periodontal tissues.Recent developments in dental material, technology and instruments however, have simplified the taskaf restoring rebuilding and rehabilitating diseased mouths. So, optimum oral health and function should be the prime objective of all treatment procedures. Because the ultimate aim will always be to restore the mouth to health and preserve this status throughout the life of a patient.

The historical aspects, principles and philosophy of endodontics: A syllabus

A. Ghazinori

The area of endodontics has expanded in recent years to include operations that formerly were not done. e.g hemisection, intentional or unintentional replantations and treatment of periodontally-endodontically involved teeth. However, treatment of pulpitis and infected root canals occupy the major part of endodontic practice. The radical treatment of pulpless teeth by extraction which was so prevalent a few decades ago has given away to conservative treatment and retention of such teeth. What was brought about this change? Essentially, it has been due to a gradual veering away from the focal infection theory, simplification of strategic pulpless teeth as abutments. Research studies that indicated the pulpless tooth were either bacteriologic or roentgenologic in most of them the method of study was erroneous and unscientific. Roentgenologic studies condemned the pulpless tooth even more than the bacteriologic studies.It remained for an Englishman, E.W.Fish, to clarify the dark points of endodontic treatments by his experiments. he cauterized the gingiva and gingival sulcuses of extracted teeth and proved that contamination of root surfaces was due to above sources.Fish carried out an even more important experiment by establishing foci of infection in the jaws of guinia pigs and found four distinct areas around the focus of infection. These areas are called as zone of infection, zone of contamination, zone of irritation and zone of stimulation, with their special characteristics.From an endodontic stand point this study has considerable significance, as it explains both the disease process occurring in bone and repair following endodntic treatment. The focus of infection is always in the root canal. The periapical tissue is essentially strile except for occasional inroads, despite this focus. As the microorganisms grow out of the root canal and into the periapical tissue they are destroyed by the polymorphonuclear leucocytes. In such cases where the microorganism overcomes the polymorphonuclear cells, an acute abcess is formed. In most cases however, the reverse is true, the microorganisms entering the bone are destroyed and a chronic abcess developes. Where defence is adequate and periapical bone will be destroyed but a wall of fibrous tissue develops and the lesion is called a granuloma. In some cases the epithelial cell rests in the periodontal membrane are stimulated from a cyst.

Histopathological study of healing in periapical lesions following endodontic treatments

A. Khayat

This study was perfomed on twenty five teeth which showed radiographic lesions( 6mm over 25 mm). the teeth were arranged in seven different groups and root canal therapy ( by warm Gutta-percha technique) as surgical intervention were performed at various time intervals. In this investigation, histologic studies of the periapical tissues begin shortly after elimination of the root canal system with or without root canal obturation. This healing demonstrated with a) replacement of granulation tissue by connective tissue, inflammatory cells diminish in number and density
b) fibroblastic activity and their differentiation of osteoblast
c) osteoblastic activity forming osteoid and trabecular bone. The newly formed trabeculae extend from the periphery of the lesion to the center and root surfaces
d) nonorganized periodontal ligament fibers return to their original orientation soon after the newly formed trabeculae reach the apical root surface and form lamina dura
Inflammatory responses may continue simultaneously with periapical tissue regeneration and bone formation. Chronic inflammatory cells seem to be present occasionally in marrow spaces of the newly formed bone. Cellular activity and bone formation are demonstrated in the presence of the lining epithelium. This is seen between newly formed bone and apical root tip and might be suggestive of healing of the periapical cyst.

Studying the effects of Bite plane application in intruding and extruding the teeth in patients with deep bite

M. Shirazi

Deep bite is a major clinical problem manifested as higher than normal overbite in anterior region of the jaws. Various studies were conducted to identify the effects of using bite plan and its results. 14 subjects with deep bite were selected out of 400 students of a school who had not proximal caries and had not lost any permanent teeth with healthy periodontal condition. 8 patients were considered as case group and the 6 other as the control group. In case group, a simple labial arc with acrylic palate that caused a gap in occlusion was placed. 2 lateral radiographs were obtained both pre and post 14 months treatment period. After cephalometric analysis, due to bite plane application significant intrusion in mandibular incisors were observed as well as elongation in both maxillary and mandibular molars.