Effect of Aging and Carotid Atherosclerosis on Multifractality of Dental Pulp Blood Flow Oscillations.

INTRODUCTION: Age-related changes of dental pulp tissue and atherosclerosis of carotid arteries as its feeding arteries could influence the functionality of pulpal circulation. The objective of our study was to evaluate the effect of aging (physiological process) and carotid bifurcation atherosclerosis (pathologic process) on the pulpal microcirculatory system using multifractal analysis of the laser Doppler flowmetry signal. METHODS: Three groups of 10 subjects were enrolled in the study: the young group (healthy subjects, 20-25 years), the middle-aged group (healthy subjects, 50-60 years), and the clinical group (subjects with carotid bifurcation atherosclerosis, 50-60 years). Pulpal blood flow (PBF) signals recorded by laser Doppler flowmetry were assessed by multifractal analysis that estimates Hölder exponents of the signal. PBF levels, the average mean values, and the range of Hölder exponents were obtained. RESULTS: PBF levels were significantly higher in the young group compared with the middle-aged and clinical groups, and the difference between the middle-aged and clinical groups was not statistically significant. The range of the Hölder exponents was narrower in the middle-aged and clinical groups than in the young group and narrower in the clinical group than in the middle-aged group. The average mean value of Hölder exponents was significantly higher in the young group than in the middle-aged and clinical groups, whereas there was no significant difference between the middle-aged and clinical groups. CONCLUSIONS: Our study investigating the multifractality of the PBF signal showed that the aging process and carotid atherosclerosis could affect the complex structure of PBF oscillations and contribute to a better understanding of pulpal hemodynamics.

Clinical antibacterial effectiveness and biocompatibility of gaseous ozone after incomplete caries removal.

OBJECTIVES: To evaluate local effect of gaseous ozone on bacteria in deep carious lesions after incomplete caries removal, using chlorhexidine as control, and to investigate its effect on pulp vascular endothelial growth factor (VEGF), neuronal nitric oxide synthase (nNOS), and superoxide dismutase (SOD). MATERIALS AND METHODS: Antibacterial effect was evaluated in 48 teeth with diagnosed deep carious lesion. After incomplete caries removal, teeth were randomly allocated into two groups regarding the cavity disinfectant used: ozone (open system) or 2% chlorhexidine. Dentin samples were analyzed for the presence of total bacteria and Lactobacillus spp. by real-time quantitative polymerase chain reaction. For evaluation of ozone effect on dental pulp, 38 intact permanent teeth indicated for pulp removal/tooth extraction were included. After cavity preparation, teeth were randomly allocated into two groups: ozone group and control group. VEGF/nNOS level and SOD activity in dental pulp were determined by enzyme-linked immunosorbent assay and spectrophotometric method, respectively. RESULTS: Ozone application decreased number of total bacteria (p = 0.001) and Lactobacillus spp. (p < 0.001), similarly to chlorhexidine. The VEGF (p < 0.001) and nNOS (p = 0.012) levels in dental pulp after ozone application were higher, while SOD activity was lower (p = 0.001) comparing to those in control pulp. CONCLUSIONS: Antibacterial effect of ozone on residual bacteria after incomplete caries removal was similar to that of 2% chlorhexidine. Effect of ozone on pulp VEGF, nNOS, and SOD indicated its biocompatibility. CLINICAL RELEVANCE: Ozone appears as effective and biocompatible cavity disinfectant in treatment of deep carious lesions by incomplete caries removal technique.

Comparison of pulpal anesthesia and cardiovascular parameters with lidocaine with epinephrine and lidocaine with clonidine after maxillary infiltration in type 2 diabetic volunteers.

OBJECTIVES: The pulpal anesthetic and cardiovascular parameters obtained by 2 % lidocaine with epinephrine (LE; 1:80,000) or clonidine (LC; 15 mcg/ml) were studied in diabetes mellitus (DM) type 2 and healthy volunteers (72), after maxillary infiltration anesthesia. MATERIALS AND METHODS: Onset and duration of pulpal anesthesia were measured by electric pulp tester; vasoconstrictive effect of used local anesthetic mixtures by laser Doppler flowmetry (LDF) through pulpal blood flow (PBF); systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were registered by electrocardiogram monitoring. RESULTS: Onset of pulpal anesthesia was shorter for LC than for LE in healthy, while it was not different in diabetic participants; duration of pulpal anesthesia was significantly longer in type 2 diabetic participants, regardless of used anesthetic mixture. Significant reduction of PBF with LE was observed during 45 min in healthy and 60 min in diabetic participants, while with LC such reduction was observed during 45 min in both groups. LE caused a significant increase of SBP in the 5th and 15th minutes in diabetic versus healthy participants, while LC decreased SBP from the 10th to 60th minutes in healthy versus diabetic participants. CONCLUSIONS: DM type 2 influences duration of maxillary infiltration anesthesia obtained with LE and LC, and systolic blood pressure during LE anesthesia. CLINICAL RELEVANCE: The obtained results provide elements for future protocols concerning intraoral local anesthesia in DM type 2 patients.

Denture stomatitis and salivary vascular endothelial growth factor in immediate complete denture wearers with type 2 diabetes.

STATEMENT OF PROBLEM: Diabetes mellitus type 2 is associated with a variety of oral mucosal changes, including an altered level of salivary vascular endothelial growth factor. However, the authors identified no studies concerning denture stomatitis and salivary vascular endothelial growth factor in immediate denture wearers with diabetes mellitus type 2. PURPOSE: The purpose of this study was to investigate the incidence of and risk factors for denture stomatitis in immediate complete denture wearers with and without diabetes mellitus type 2 and to investigate the relationship between levels of salivary vascular endothelial growth factor and clinical forms of denture stomatitis in both groups. MATERIAL AND METHODS: Individuals without diabetes (n=42) or with diabetes mellitus type 2 (n=36) who were candidates for complete immediate dentures were included in the study. After 1 year of wearing relined immediate dentures, participants were evaluated for denture stomatitis and potential contributing factors. Salivary vascular endothelial growth factor levels were measured with enzyme-linked immunosorbent assays. Data were analyzed with the χ(2) test or the Student t test where appropriate, as well as with binary logistic regression analysis. RESULTS: The incidence of denture stomatitis was 61% in participants with diabetes mellitus type 2 and 38% in those without diabetes. Low denture stability and diabetes mellitus type 2 were risk factors for denture stomatitis. Salivary vascular endothelial growth factor concentrations at the beginning of the study were 557.6 ±94.7 pg/mL in participants with diabetes mellitus type 2 and 103.5 ±21.6 pg/mL in those without diabetes. In Newton Type I and Newton Type II denture stomatitis, vascular endothelial growth factor levels were 460.9 ±55.4 pg/mL and 1445.2 ±422.1 pg/mL in individuals with diabetes and 73.2 ±10.0 pg/mL and 306.5 ±22.6 pg/mL in those without diabetes. CONCLUSIONS: Perceived denture stability and diabetes mellitus type 2 are independent risk factors for the occurrence of denture stomatitis. Altered salivary vascular endothelial growth factor levels and denture stomatitis are more prevalent in denture wearers with diabetes mellitus type 2.

Levobupivacaine vs. bupivacaine for third molar surgery: quality of anaesthesia, postoperative analgesia and local vascular effects.

OBJECTIVES: The main purpose of this prospective, double-blind, randomized study was to evaluate anaesthetic parameters, postoperative analgesia and vasoactive properties of levobupivacaine and bupivacaine for lower third molar surgery. MATERIAL AND METHODS: Sixty patients (ASA I) were scheduled for lower third molar surgery under inferior alveolar nerve block, lingual nerve block and buccal nerve block (mandibular nerve blocks) obtained with 3 ml of 0.5 % levobupivacaine and 3 ml of 0.5 % bupivacaine. Success rate, onset and duration of three nerve bocks were evaluated by electrical pulp testing, pinprick testing and signs of soft tissue anaesthesia (patient-reported numbness). Intensity of intraoperative anaesthesia and postoperative analgesia were measured with visual analogue scale (VAS) and numeric rating scale (NRS). The time of first postoperative pain reported and analgesic consumption were also recorded. The laser Doppler flowmetry was used for the measurement of the first premolar pulpal blood flow. RESULTS: There were no differences between levobupivacaine and bupivacaine regarding the success rate, onset and duration of mandibular nerve blocks as well as intensity of postoperative analgesia and analgesic consumption. Intensity of intraoperative anaesthesia and duration of postoperative analgesia were significantly higher in the levobupivacaine than in the bupivacaine group. Both anaesthetics showed similar biphasic vasoactive effect. CONCLUSIONS: Levobupivacaine 0.5 % achieved superiority over bupivacaine 0.5 % in the intensity of intraoperative anaesthesia and duration of postoperative analgesia for lower third molar surgery under the mandibular nerve blocks. CLINICAL RELEVANCE: It seems that the plain levobupivacaine (0.5 %) could be an effective alternative to plain bupivacaine (0.5 %) in those dental procedures which require profound bone and soft tissue anaesthesia.

Efficacy and safety of intraseptal and periodontal ligament anesthesia achieved by computer-controlled articaine + epinephrine delivery: a dose-finding study.

OBJECTIVES: The main purpose of this study was to evaluate the dose-dependent anesthetic efficacy of the intraseptal anesthesia (ISA) and periodontal ligament anesthesia (PLA) obtained with different volumes of 4 % articaine and 1:100,000 epinephrine (Ar + Ep) in human mandibular premolars, using a computer-controlled local anesthetic delivery system (CCLADS). The safety profile of Ar + Ep was also studied by investigating the stability of cardiovascular parameters. MATERIAL AND METHODS: One hundred and eighty randomly selected healthy volunteers (ASA I) entered the single-blinded study to receive 16 mg + 4 µg, 24 mg + 6 µg, and 32 mg + 8 µg of Ar + Ep, obtained with different volumes (0.4, 0.6, and 0.8 ml, respectively), for the ISA and PLA. Success rate, onset, and duration of profound pulpal anesthesia were evaluated by the electrical pulp tester, while the width of the anesthetic field and duration of soft tissue anesthesia were recorded using the pinprick testing. A monitor was used for the measurement of cardiovascular parameters. RESULTS: A dose-dependent duration of pulpal and soft tissue anesthesia was obtained only by the ISA. Success rate, duration of both pulpal and soft tissue anesthesia, and its width were significantly better in the ISA compared with the PLA. No significant cardiovascular changes were seen in both groups. CONCLUSIONS: It can be suggested that 0.6 and 0.8 ml of 4 % Ar + 1:100,000 Ep, delivered by CCLADS, offer high success rate and effective clinical parameters of ISA as a primary anesthesia. CLINICAL RELEVANCE: It seems that dental procedures requiring profound pulpal, bone, and soft tissue anesthesia could be effectively and safely obtained by mentioned anesthetic protocol.

Dental pulp blood flow and its oscillations in women with different estrogen status.

INTRODUCTION: The skin microcirculation is significantly affected by serum estrogen levels. The objective of this study was to investigate the effects of estrogen serum level changes associated with the menstrual cycle and postmenopause on dental pulp blood flow (PBF) as well as its dynamics. METHODS: Young women at the menstrual phase (low serum estrogen levels) and in the mid-cycle phase of the menstrual cycle (high serum estrogen levels) and postmenopausal women were enrolled in the study. PBF and its oscillations were measured by laser Doppler flowmetry and analyzed by using wavelet transform. Serum levels of estradiol-17ß were measured by immunoassay. RESULTS: PBFs of young women in the menstrual phase and postmenopausal women were mutually similar and significantly lower than those of young women in the mid-cycle period. With respect to the mid-cycle phase, relative amplitude and power were significantly increased in the interval 0.0095-0.02 Hz and decreased in the intervals 0.02-0.06 and 0.06-0.2 Hz in the menstrual phase. A significant decrease in 0.0095-0.02 Hz and increase in 0.02-0.06, 0.06-0.2, 0.2-0.6, and 0.6-1.6 Hz intervals were observed in postmenopause. CONCLUSIONS: The study has shown that the menstrual phase of the menstrual cycle and postmenopause have similar PBF decrease, but PBF oscillations are differently affected in the mid-cycle phase.

The levels of vascular endothelial growth factor and bone morphogenetic protein 2 in dental pulp tissue of healthy and diabetic patients.

INTRODUCTION: Vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP 2) are growth factors (GFs) identified within the dentine-pulp complex and involved into the cellular events connected to the pulp-healing response. It is well established that the expression of these GFs is increased in different tissues in diabetes mellitus. Because there are no data concerning the levels of VEGF and BMP 2 in human dental pulp, the aim of present study was to quantify VEGF and BMP 2 levels in intact dental pulp and dental pulp that underwent reactive dentinogenesis in healthy and diabetic human subjects. METHODS: The study was conducted on 28 healthy and 28 subjects with controlled diabetes type II who underwent pulp extirpation as a part of prosthetic rehabilitation. Pulp were collected from intact teeth and teeth treated by indirect pulp capping. The levels of VEGF and BMP 2 were determined in the pulp tissue lysates with enzyme-linked immunosorbent assay. RESULTS: The levels of VEGF and BMP 2 were significantly higher in intact teeth pulp of diabetic than in healthy subjects. The concentrations of these GFs were significantly lowered in teeth with indirect pulp capping both in healthy and diabetic persons. Furthermore, VEGF and BMP 2 levels were in strong positive correlation. CONCLUSIONS: Similar changes in the levels of VEGF and BMP 2 in intact and treated teeth of healthy and diabetic patients could be suggestive of associated roles of these GFs in responses of healthy and diabetic dental pulp.

Impairment of acetylcholine-mediated endothelium-dependent relaxation in isolated parotid artery of the alloxan-induced diabetic rabbit.

The aim of this study was to assess the effect of type 1 diabetes mellitus (induced by a single intravenous injection of 100 mg kg(-1) of alloxan) on acetylcholine (ACh)-induced relaxation in isolated rabbit parotid gland feeding artery. Isometric force measurements and quantification of inducible nitric oxide synthase (iNOS) mRNA by real-time RT-PCR were made in parotid artery rings from diabetic and control rabbits. Acetylcholine induced concentration- and endothelium-dependent vasorelaxation that was significantly decreased in parotid artery rings from diabetic rabbits. Schild analysis of the ACh vasorelaxant effect, in the presence of selective muscarinic receptor antagonists, revealed involvement of the M(3) receptor subtype in parotid artery rings from both control and diabetic rabbits, with no change in antagonist affinity constants. The inhibitory effects of indomethacin, a non-selective inhibitor of cyclooxygenase, and of high potassium, an inhibitor of hyperpolarization, on ACh vasorelaxation were increased. The effect of N(G) -nitro-l-arginine, a non-selective inhibitor of NOS, was decreased in diabetes. S-methylisothiourea, a selective inhibitor of iNOS, significantly reduced ACh vasorelaxation only in parotid artery rings from diabetic rabbits. Also, up-regulation of iNOS mRNA expression was detected in parotid artery rings from diabetic rabbits. These results suggest that in parotid artery rings from diabetic rabbits, impaired endothelium-dependent vasorelaxation to ACh appears to be caused by the loss of a nitric oxide-mediated component and increased iNOS expression, and is unlikely to be caused by a change at the M(3) receptor level.

ACh- and VIP-induced vasorelaxation in rabbit facial artery after carotid artery occlusion.

OBJECTIVES: The influence of carotid artery occlusion (10, 30 and 60 min) on regulatory mechanisms implicated in the vasorelaxant responses of isolated glandular branch of rabbit facial artery to acetylcholine (ACh) and vasoactive intestinal polypeptide (VIP) was examined. DESIGN: In organ bath studies with arterial rings precontracted with phenylephrine (1 microM), before and after carotid artery occlusion, changes in isometric tension were recorded. RESULTS: Endothelium-dependent vasorelaxation by ACh and endothelium-independent vasorelaxation by VIP were significantly reduced, started from 30 and 10 min of carotid occlusion, respectively. Inhibitory effect of indomethacin on ACh vasorelaxation was enhanced whilst effect of N(G)-nitro-L-arginine reduced, started from 30 min of carotid occlusion. Sodium nitroprusside-induced vasorelaxation was not changed after carotid occlusion. Inhibition of VIP vasorelaxation by L-N(omega)-nitroarginine-2,4-L-diaminobutyric-amide, was reduced, started from 30 min of carotid occlusion. Forskolin enhanced VIP-induced vasorelaxation in control rings but this effect was reduced started from 30 min of occlusion. In the presence of VIP, vasorelaxant effect of ACh was increased; the increase was reduced, started from 10 min of carotid occlusion. CONCLUSIONS: The present investigation provides evidence for the decreased responsiveness to both, ACh-endothelium-dependent and VIP-endothelium-independent vasorelaxation in rabbit facial artery after carotid occlusion. In addition, the data suggest that ischaemia alters contribution of endothelial nitric oxide (eNO) and prostaglandin to ACh, and vascular smooth muscle's cAMP and neuronal NO to VIP vasorelaxant effects.

Isolated rat inferior mesenteric artery response to adenosine: possible participation of Na+/K+-ATPase and potassium channels.

Adenosine (10(-7)-3 x 10(-4) M) produced concentration-dependent and endothelium-independent relaxation of isolated rat inferior mesenteric artery. Application of indomethacin (10(-5) M) or N(G)-nitro-L-arginine (10(-5) M) did did not alter adenosine-elicited relaxation. Conversely, in the presence of high concentration of K+ (100 mM), ouabain (10(-4)) or combination of tetraethylammonium (5 x 10(-4) M) and glibenclamide (10(-6) M), adenosine-evoked relaxant effect was significantly reduced. In K+-free solution, 1-3 mM potassium induced relaxation, which was partially reversed by ouabain (10(-4) M). 1,3-Dipropyl-8-cyclopentylxanthine (10(-9) M), an A1-receptor antagonist, did not affect adenosine-evoked relaxation. Oppositely, 8-(3-chlorostyryl)-caffeine (3 x 10(-7)-10(-6) M), a selective A2A receptor antagonist, significantly inhibited adenosine-induced relaxation in a concentration-dependent manner (pA2 = 6.74). These results indicate that in the isolated rat inferior mesenteric artery, adenosine produces endothelium-independent relaxation, which is partly induced by activation of smooth muscle adenosine A2A receptors, and further mediated by the activation of smooth muscle Na+/K+-ATPase and opening of mixed population of K+ channels.

Effect of the vascular endothelium on contractions induced by noradrenaline and phenylephrine in perforating branch of the human internal mammary artery.

The effects of noradrenaline (Nor) and phenylephrine (Phe) on the isolated, non-precontracted perforating branch of the human internal mammary artery (HIMA) were investigated. Nor and Phe induced concentration-dependent contractions of intact and endothelium-denuded arterial rings with no statistically significant differences between the pEC(30) and maximal response values. The pretreatment of arterial rings with indomethacin had no effect on Nor- and Phe-induced contractions of both, intact and endothelium-denuded preparations. The pre-addition of L-NMMA did not affect contractions of perforating branch of the HIMA evoked by Nor, but provoked significant potentiation of Phe-induced contractions of perforating branch of the HIMA both intact and denuded of endothelium only at Phe concentration higher than 3 x 10(-6)M. The effects of selective alpha1-adrenoceptor antagonist, prazosin and selective alpha2-adrenoceptor antagonist, rauwolscine were concentration-dependent, and they induced a significant shift to the right (for both studied antagonists) of the concentration-response curves for Nor in both preparations with or without endothelium. The effects of prazosin and rauwolscine on the concentration-response curves for Phe were similar. In conclusion, this study has shown that Nor and Phe induce concentration-dependent contractions of the perforating branch of the HIMA. Removal of the endothelium did not modify this effect. Products of cyclooxygenase pathway had no influence on Nor and Phe action. Endothelium derived nitric oxide (NO) had no modulatory effect of Nor-induced contractions, but inhibition of NO synthesis provoked potentiation of Phe-induced contractions either in intact or endothelium-denuded preparations. The mechanism of this effect remains still unclear. On the basis of differential affinity of the antagonists and affinities of Nor and Phe themselves, we suggest that alpha1-adrenoceptor subtype is probably involved in the Nor- and Phe-induced contraction of the perforating branch of the HIMA both intact or denuded of endothelium.

Influence of the endothelium on the vasorelaxant response to acetylcholine and vasoactive intestinal polypeptide in the isolated rabbit facial artery.

The aim was to examine the influence of the endothelium on acetylcholine (ACh) and vasoactive intestinal polypeptide (VIP) functional responses in the isolated glandular branch of rabbit facial artery precontracted with phenylephrine as well as the potential contribution of nitric oxide (NO) and prostanoids in the ACh- and VIP-induced effects. Acetylcholine caused endothelium-dependent and VIP endothelium-independent relaxations of facial artery. The effect of ACh was partly inhibited by NG-monomethyl-l-arginine (l-NMMA, a non-selective NO synthase inhibitor) or by indomethacin (a cyclooxygenase inhibitor) while being completely blocked after concomitant addition of l-NMMA and indomethacin. The relaxation of the facial artery caused by ACh was unaffected by 65 mm KCl. The VIP-induced vasodilation was potentiated by forskolin (an adenylate cyclase stimulator) and partly reduced by l-NMMA or S-methyl-l-thiocitrulline (l-SMTC, a neuronal NO synthase inhibitor), whereas it was unaffected by indomethacin. These results suggest that ACh effects on the rabbit facial artery are mediated through release of endothelium-derived NO and cyclooxygenase products, while the effect of VIP is most probably mediated by an increase of cyclic adenosine 3',5'-monophosphate (cAMP) in vascular smooth muscles and by VIP-induced release of NO from perivascular nerve fibers.