Evaluation of two flap designs on the mandibular second molar after third molar extractions

BACKGROUND

The extraction of third molars is associated with some clinical outcomes and periodontal problems. It is imperative to note that the type of incision used in the surgery for the removal of the impacted third molar is critical. The design of the flap influences the healing of the surgically created defect and damage to the distal periodontal area of the adjacent second molar. However, till date, there have been conflicting reports on the influence of different flap designs used for the surgical removal of impacted third molars.

AIM

The present study aimed to comparatively evaluate the clinical outcomes and periodontal status of the adjacent second molar, when two different flap designs, namely, the envelope and the modified triangular flap designs were used.

MATERIALS AND METHODS

Sixty female patients with bilateral impacted third molars completed the study with envelope flap on one side and modified triangular flap design on the other side of the mandible for third molar removal. Clinical parameters including pain, dehiscence and swelling were assessed postoperatively and periodontal probing depth (PPD) on the distal aspect of adjacent second molar were assessed both pre- and post-operatively.

RESULTS

The results were assessed on 1, 3 and 8 days for pain using visual analog scale. The subjective perception of swelling was evaluated on 3, 7 and 15 days postoperatively in a similar manner. The results of the periodontal parameters were evaluated both preoperatively and 3 months postoperatively, with cautious exploration using a University of North Carolina (UNC)-15 periodontal probe. The statistically significant results for swelling and PPD were noted for the two flap groups using the Chi-square test (P < 0.05).

CONCLUSION

The study revealed that the modified triangular flap had lesser postoperative PPDs and dehiscence. The envelope flap was better when swelling was analyzed. The pain scores, though slightly higher for the modified triangular flap group, were not statistically significant.

Melatonin protects against alterations in hippocampal cholinergic system, trace metals and oxidative stress induced by gestational and lactational exposure to cadmium

Dietary exposure to cadmium, even at lower doses, can lead to free radical induced neurotoxicity, neurobehavioral changes and alteration in neurotransmitters. Such changes are likely to be more pronounced in the developing brain due to incompleteness of blood brain barrier (BBB). Hippocampus being the seat of intelligence has a role in learning and cognitive behavior and any damage to hippocampus during developmental stage is likely to result in neurodegenerative changes in later life. To this end, fetal and neonatal exposure to cadmium was induced by exposing pregnant dams of Swiss albino strain throughout the period of gestation and following parturition up till 5^th day post partum (pp) through drinking water (3ppm/animal/day). The neonates were sacrificed on day 6 pp and indices of oxidative stress, levels of trace elements and changes in cholinergic system were evaluated in the hippocampus. Increased lipid peroxidation, surge in reactive oxygen species (ROS), depressed antioxidant defense, increased accumulation of cadmium, differential alterations in trace elements and decreased activity of AChE were the features of cadmium toxicity. Simultaneous administration of melatonin to cadmium challenged animals offset these detrimental changes. The results suggest that melatonin co-administration can effectively protect against the adverse effects of cadmium on endogenous antioxidant status, changes in trace metal concentrations and compromised hippocampal cholinergic system.

Toxicokinetics and bioavailability of oral and intravenous 1,1-dichloroethylene

Although aliphatic halocarbons have been identified as contaminants of drinking water supplies, little definitive information is available on their gastrointestinal (G.I) absorption and toxicokinetics. Therefore, a study of a representative halocarbon, 1,1-dichloroethylene (1,1-DCE), was undertaken to contrast the kinetics of the chemical following iv injection with that following oral administration. Four dosage-levels of 1,1-DCE (10, 25, 50, and 100 mg/kg BW) in 50% aqueous polyethylene glycol 400 were given iv and po to fasted and nonfasted male Sprague-Dawley rats. Serial blood samples were taken from the tail artery of the lightly etherized animals for up to 490 min after dosing. 1,1-DCE concentrations in the whole blood were determined by gas chromatographic head-space analysis. Evaluation of the iv data revealed that disappearance of 1,1-DCE from the systemic circulation followed a triexponential pattern. Light ether anesthesia did not appear to alter the pharmacokinetics of iv-injected 1,1-DCE. There was no difference between nonfasted and fasted iv rats in biological half-life (t1/2) or in any other pharmacokinetic parameter. Total body clearance, t1/2, apparent volume of distribution and volume of distribution in the central compartment did show increases with increasing dose in these animals. Oral dosing experiments revealed that 1,1-DCE was absorbed very rapidly and completely from the G.I. tract. Peak blood levels were reached 2 to 8 min following oral administration of 1,1-DCE as an aqueous suspension. The t1/2 of 1,1-DCE in orally dosed rats was somewhat longer than in their iv counterparts. The t1/2 values for nonfasted, orally dosed rats were longer than for their fasted counterparts, suggesting delayed absorption due to the presence of food in the G.I. tract. Bioavailability of 1,1-DCE, as determined by comparing areas under blood concentration versus time curves (AUCs), was equivalent in animals given the same dose of 1,1-DCE iv and po. AUCs increased with increasing dose in iv and po groups, but the increases were not proportional to dose.