Morphological changes in oral mucosa of rabbits induced by light emitting diode [LED] used as dental curing light

A dental curing light is apiece of dental tool that is used for the hardening of light cure composites. Many studies have shown these lights induce changes in DNA, mitosis and mitochondria through free radicals production. Light emitting diode [LED] are most commonly used and claim less hazards to the adjacent soft tissues. Current study was therefore designed to observe the morphological changes induced by light emitting diode [LED] as a dental curing light source in oral mucosa of experimental animals

Fifty rabbits were divided into 5 groups [4 experimental and 5th as a control group]. Cervical margin of central incisors of each animal in the experimental groups was exposed 3 times with LED light; duration of each exposure being 40 seconds with a gap of 30 seconds. Punch biopsies were taken after 24 hours, 48 hours, Iweek and 2weeks from group 1, 2, 3 and 4 animals respectively

Results showed ulceration [4%], acanthosis and vascular pathological changes [100%] enlarge [bulbous] rete ridges [97.5%], basal layer vacuolization [85%], acantholysis [27.5%] and atypical mitosis [10%] in all the experimental animals. With passage of time, a significant increase [P=0.000] in frequency of basal cell hyperplasia [90% in group 1 to 100% in group 4] and basal layer atypia [70% in group 1 to 90% in group 4] was observed. While inflammation dropped from 100% in group 1 to 0% in group 4 [P=0.000] due to healing of tissues. Changes were similar to the previous studies except some severe effects like atypical mitosis and basal layer atypia were observed which may be attributed to increase in number of light exposures in our study that is in compliance with the clinical practice in our set up

These findings may help in creating awareness among the dental practitioners to use dental curing lights with caution keeping appropriate safety measures for the adjacent oral soft tissue in consideration

Immunohistochemical localization of keratin in 100 cases of squamous cell carcinoma

The keratinizing tumors are less radiosensitive and non-keratinizing are more radio responsive. This study was carried out to detect the presence of keratin in apparently non- keratinizing poorly differentiated squamous cell carcinomas by immunoperoxidase staining. It is a cross sectional and descriptive study conducted at King Edward Medical College, Post Graduate Medical Institute, Lahore. A total of 100 patients suffering from squamous cell carcinomas were included in the study. Both H and E and immunoperoxidase staining were performed. The results of both types of staining were compared for each case. Four groups were identified. Forty nine cases showed obvious keratinization on both H and E and immunoperoxidase staining. Twenty cases had doubtful keratinization on H and E but showed more obvious keratinizaton on immunoperoxidase staining. Ten cases were non-keratinizing on H and E as well as on immunoperoxidase analysis. Cytokeratin can be used as a tumour marker for squamous cell carcinoma. The immunohistochemical technique can help us in revising and modifying our H and E impression of a squamous cell carcinoma

comparison of histological appearances of Hodgkin's disease in Pakistani and Saudi patients

Hodgkin's disease [HD] is a relatively rare lymphoma that affects younger as well as older persons. It is reported in the Western as well as Asian studies that HD is a rare disease in developing world. It is commoner in males in most of the countries and shows a bimodal pattern of age. The commonest subtype is nodular sclerosis in the west and mixed cellularity in the eastern and developing countries. The present study compares eight years' data of HD as regard age, sex, site of anatomical presentation and subtypes according to WHO classification among Pakistani and Saudi patients. This retrospective comparative study included 211 cases of HD from various institutions of Lahore, Pakistan; and 78 cases retrieved from the data of King Abdul Aziz Hospital and Oncology Centre, Jeddah, Saudi Arabia. The analysis of both data of HD showed lack of bimodal age pattern and was common among younger age. Male was the dominating sex. Cervical group of lymph nodes was the commonest presenting site. Mixed cellularity HD [MCHD] was the commonest subtype among Pakistani patients whereas Nodular Sclerotic HD [NSHD] was more common among Saudis. A comparison of the pattern of Pakistani and Saudi data of HD showed lack of bimodality in both. The male sex predominated. Morphologically the MCHD and NSHD were the commonest subtypes in Pakistani and Saudi patients respectively