Temperature rise during adhesive and composite polymerization with different light-curing sources

AIM

This study evaluated the temperature rise of the adhesive system Single Bond (SB) and the composite resins Filtek Z350 flow (Z) and Filtek Supreme (S), when polymerized by light-emitting diode (LED XL 3000) and quartz-tungsten halogen (QTH Biolux).

METHODS

Class V cavities (3 yen2 mm) were prepared in 80 bovine incisors under standardized conditions. The patients were divided as follows: G1: Control; G2: SB; G3: SB + Z; G4: SB + S. The groups were subdivided into two groups for polymerization (A: QTH, B: LED). Light curing was performed for 40 s and measurement of temperature changes during polymerization was performed with a thermocouple positioned inside the pulp chamber. Data were statistically analyzed using ANOVA and Tukey tests.

RESULTS

The factors material (P<0.00001) and curing unit (P<0.00001) had significant influence on temperature rise. The lowest temperature increase (0.15 degrees C) was recorded in G2 B and the highest was induced in G1 A (0.75 degrees C, P<0.05). In all groups, lower pulp chamber temperature measurements were obtained when using LED compared to QTH (P<0.05).

CONCLUSION

QTH caused greater increases in tooth temperature than LED. However, both sources did not increase pulpal temperature above the critical value that may cause pulpal damage.

[Topical versus peribulbar anesthesia in nonpenetrating deep sclerectomy]

INTRODUCTION

Ophthalmic surgery has developed enormously over the past few years. Topical anesthesia is a safe and current procedure in cataract surgery, giving patients quicker and more comfortable recovery. Some authors have used this type of anesthesia for trabeculectomy with good results. This study aims to assess the patient's pain and comfort during and 1 day after nonpenetrating deep sclerectomy compared to peribulbar anesthesia.

METHOD

A visual analog pain scale (0-10) was applied to 69 patients 15 min and 24 h after a nonpenetrating deep sclerectomy procedure. Topical anesthesia (proximetacaine 0.5% drops) associated with an intravenous sedation with propofol was used in 36 patients (group 1) and peribulbar anesthesia (lidocaine 2% associated with bupivacaine 0.75%) was given to 33 patients (group 2) in a randomized and prospective way. The surgical team was the same for all procedures. Results were compared using a Mann-Whitney U test.

RESULTS

Mean age (+/- standard deviation) was 60.25+/-15.90 years in group 1 and 59.15+/-15.36 years in group 2 (p=0.871). For the first evaluation (15 min after surgery), the mean values and their respective deviations were the following: 0.11 +/- 0.40 (0-2) in group 1 and 0.82+/-1.49 (0-5) in group 2 (p=0.014). After 24 h, the mean values and deviations were as follows: 2.83 +/- 1.34 (1-6) in group 1 and 2.45+/-2.09 (0-8) in group 2 (p=0.125).

DISCUSSION

Pain perception by the patient undergoing nonpenetrating deep sclerectomy was statistically different between the two groups in the first evaluation (15 min after the procedure). The topical anesthesia (associated with propofol sedation) group had less pain sensation. The first 24 h assessment showed no significant difference between the groups.

CONCLUSION

Topical anesthesia (associated with propofol sedation) is a valuable and interesting alternative for patients undergoing nonpenetrating deep sclerectomy, providing the same or slightly better comfort than peribulbar anesthesia.

[Ionized calcium and magnesium as interdependent variables in blood pressure origin in healthy adolescents]

INTRODUCTION

Growing evidence indicates that diet divalent cations--ionized calcium (Ca) and magnesium (Mg)--and MN blood group polymorphism may be associated with essential arterial hypertension.

OBJECTIVES

To assess a possible relationship between serum ionized Ca and Mg and MN blood group polymorphism with blood pressure (BP) and body mass index (BMI).

POPULATION AND METHODS

The study group consisted of 173 healthy adolescents, 96 female (55.5%) and 77 male (44.5%), with mean age of 13.0 +/- 1.7 years. Serum ionized Ca and Mg were determined by standardized methods based on detection by specific electrodes. MN blood group polymorphism was determined by immunoaglutination of erythrocytes with monoclonal antibodies. BP was evaluated based on AHA recommendations. BMI was calculated as weight divided by squared height (Kg/m2). The statistical method used was the Pearson correlation.

RESULTS

In this population no significant correlation was found from serum ionized Ca (mean: 1.07 +/- 0.06 mmol/L) and Mg (mean: 1.15 +/- 0.97 mmol/L) with systolic BP (mean: 113.1 +/- 10.7 mmHg) and diastolic BP (mean: 66.1 +/- 10.1 mmHg). In contrast there was an inverse correlation between the quotient ionized Mg/ionized Ca (0.45 +/- 0.05) and diastolic BP (p = 0.029; r = -0.381). A positive correlation was found between BMI (20.57 +/- 3.24 Kg/m2) and systolic BP (p = 0.007; r = 0.24) and diastolic BP (p = 0.016; r = 0.22). No correlation was found between ionized Ca, ionized Mg and BP with MN blood group polymorphism.

CONCLUSIONS

In this population of healthy adolescents there was a dependence between diastolic BP and serum ionized Mg/ionized Ca. There was no interindividual BP and ionized Ca and Mg variation dependent from genetic variation.