Bupivacaine combined with morphine for patient-controlled epidural analgesia after thoracotomy: high volume and low concentration vs. low volume and high concentration.

OBJECTIVE: In this prospective randomized controlled study, we aimed to evaluate the effects of the administration of equal doses of bupivacaine and morphine (BM) at high volume and low concentration (HV-LC) or low volume and high concentration (LV-HC) on the number of drugs consumed, pain scores and side effects. PATIENTS AND METHODS: We randomized 64 patients who underwent thoracotomy into two groups. Group 1 received a solution prepared with 0.12% bupivacaine and 0.05 mg/cc morphine, administered with a basal infusion rate of 4 cc/h, a 2-cc bolus dose, and a 30-minute lockout time. Group 2 received a solution prepared with 0.48% bupivacaine and 0.2 mg/cc morphine, administered with a basal infusion rate of 1 cc/h, a 0.5-cc bolus dose, and a 30-minute lockout time. We compared patient-controlled epidural analgesia (PCEA) usage doses, pain scores, sensory and motor block, hemodynamic effects, side effects, and patient satisfaction in the postoperative periods. RESULTS: An increase in drug consumption with PCEA was found in the first 24 hours postoperatively in Group 2 (p<0.05). Resting visual analog scale (VAS) scores were statistically significantly higher at hours 2, 28, 32, 36, 44 and coughing VAS scores were also higher at hours 2 and 20 in Group 2. Heart rates in Group 2 were lower than in Group 1 at hours 16, 24, 44 and 48 (p<0.05). The cephalic spread of the sensory block in Group 1 was more extensive (p<0.05). The groups demonstrated no significant differences regarding side effects and patient satisfaction (p>0.05). CONCLUSIONS: The HV-LC approach resulted in better analgesia, less drug consumption, and greater cephalic spread of sensory block than the LV-HC approach. Both applications were effective and safe in terms of analgesia and side effects.

Effect of calcium hydroxide and combinations of Ledermix and calcium hydroxide on inflamed pulp in dog teeth.

The effects of Ledermix+calcium hydroxide (Ca(OH)2) or Ca(OH)2 alone on inflamed pulp tissues of dogs were studied. Fifty-nine upper incisor teeth of 10 dogs were used. Class V cavities were prepared and filled with amalgam after placement of decayed dentin particles. After 7 days, the decayed dentin and alloy were removed, and the pulps of the teeth were exposed. Ledermix and Ca(OH)2 mixtures or Ca(OH)2 alone were applied to the cavities. At the end of 7, 30, and 90 days, the teeth were extracted and examined histopathologically. Inflammation was found to be more prevalent in the 7- and 30-day groups that were treated with the Ledermix+Ca(OH)2 combination, whereas fibrosis and necrosis were nearly similar in both groups. In the 90-day groups, no inflammation was seen. No difference between the two 90-day groups with regard to reparative dentin was found.

A scanning electron microscopic study of external root resorption in replanted dog teeth.

Root resorption after replantation of mature permanent dog incisors was examined by scanning electron microscopy. Three groups consisting of three extracted teeth each were kept in a saline solution for 5, 30, and 120 min before replantation. The first group was replanted with the pulp intact. The second and third groups were replanted after root canal filling by Calciobiotic Root Canal Sealer. After 90 days, the teeth were extracted and the apical root surfaces were examined. Severe inflammatory root resorption was observed in the first (intact pulp) group. For the root canal filled teeth, the degree of root resorption was observed to be much less in those kept in saline for 30 min than in those kept for 120 min.

Effects of Nd: YAG laser, air-abrasion and acid-etching on human enamel and dentin.

The effects of the Nd:YAG laser, air-abrasion and acid-etching systems on mineral content and surface morphology of cut dentin and enamel were examined in 10 extracted human teeth. Enamel specimens were lased for two seconds at a fluence of 0.75 J and a frequency of 15 Hz, air-abraded for two seconds with 50 micron Al-oxide and etched for 60 seconds with 37% ortho-phosphoric acid. Dentinal specimens were subjected to the same procedure for half the time. Untreated areas of the same specimens served as the control. Morphologically, the lased dentin showed an apparently melted surface with partial obstruction of the dentin tubules, as well as cracks along the lased surface. Air-abrasion created very irregular surfaces on enamel and dentin. Dentin tubules were observed on the acid-etched dentin samples but not the air-abraded surfaces. The Nd:YAG laser created the most surface irregularity on both enamel and dentin. Laser treatment appeared to alter the chemical structure and surface morphology of the dentin and enamel.

Effects of the Nd:YAG laser, air-abrasion, and acid-etchant on filling materials.

The purpose of this study was to determine any inadvertent effects of the neodymium: yttrium-aluminium-garnet (Nd:YAG) laser, air-abrasion, and ortho-phosphoric acid on some conventionally used dental filling materials [amalgam, composite resin, compomer, glass-ionomer cement (GIC), and ceromer], when they were used for purposes of margin etching and assessed according to standard enamel etching parameters using a total of five fillings. The surfaces of the filling materials were polished. One sample from each material group was exposed to laser (at 0.75 J, 15 pps) and air abrasion (with Al-oxide powder, 60 psi) for 2 s and to the 37% ortho-phosphoric acid for 60 s. The exposed materials were examined under Scanning Electron Microscopy (SEM). After laser treatment most specimens showed recrystallized areas, the GIC surface being the most affected. There were some pores and cavities on the amalgam surface following laser treatment. The abraded surfaces showed mechanical abrasions. The acid etchant showed the least effect. During the application of laser or air-abrasion, the adjacent tooth or filling surface must be protected or the dentist must be careful.