To determine the changes in surface gloss of different composite materials after simulation of me... more To determine the changes in surface gloss of different composite materials after simulation of mechanical and chemical aging mechanisms. 36 specimens were fabricated for each material and polished with 120-, 220-, 500-, 1200-, 2400- and 4000- grit SiC abrasive paper, respectively. Gloss measurements were made with a glossmeter (Novo-Curve) prior to testing procedures. Specimens of each material were randomly divided into three groups. Group 1 was conditioned for 7 days at 37 degrees C in 75% ethanol aqueous solution. Group 2 was immersed in fluoride gel (Elmex Gelée) at 37 degrees C for 1 hour. Group 3 was subjected to simulated toothbrushing with an electric toothbrush while being immersed in toothpaste. Surface gloss measurements were made subsequently. Significant difference between surface gloss of the composite materials tested were detected after simulated brushing (Kruskal Wallis, P < 0.05). With the exception of Filtek Silorane, all composite materials tested were signifi...
The aim of this study was to examine the importance of a transitional ion concentration zone at t... more The aim of this study was to examine the importance of a transitional ion concentration zone at the apical foramen during electronic root canal length measurement (ERCLM). The model comprised 21 extracted single-rooted human teeth, divided into two experimental groups and one control group, each of seven teeth. The anatomical tooth length was determined from the site of reference on the tooth crown to the canal orifice and was measured using an endodontic file and a vernier caliper. Two aqueous solutions of various NaCl, KCl and CaCl2 concentrations were mixed with agar. The Na+, K+ and Ca++ concentrations corresponded to the average value of each group as determined by atomic spectrophotometry evaluation of the extirpated human pulps. The agar containing cations was injected into the root canals after their preparation to a foramen diameter of 0.70 mm. The control teeth were then completely immersed in agar having the same concentration of cations as the agar inside the canal. In the first experimental group (group 1), the teeth were immersed in agar so that the ion concentration was higher inside the canal; in the second experimental group (group 2), the concentrations were reversed. In all three groups, ERCLM was performed by an EED 11--resistance type device. Length d1 was defined as the length of the root when measured to a value one degree less than the test value. Length d2 was defined as the length of the root inducted by the test value, which corresponded to the resistance of the periapical agar. In group 1 the average d1 length was 0.44 +/- 1.05 shorter than the anatomical foramen (AF), and in group 2, 1.11 +/- 0.43 mm longer than AF. In the control group the d1 length was on average--3.02 +/- 3.72 mm from the AF. The d1 values of all groups were not statistically significantly different from the anatomical length (AL). In all three experimental groups the d2 length was statistically significantly different from the AL (P &lt; 0.05, t-test); group 1 d2 = AL + 6.32 +/- 1.38 mm; group 2 d2 = AL + 6.27 +/- 1.47; control group d2 = AL + 9.15 +/- 1.00 mm. The results of this study indicated that when the electroconductive medium in the canal had a different ion concentration than the periapex, and the canal orifice had a wide diameter (0.70 mm), the transitional concentration zone influenced the accuracy of measurement during ERCLM with a resistance type device. When ion concentrations inside and outside the canal were identical, in teeth with a wide foramen diameter (0.70 mm or more) the lack of a transitional ion concentration zone meant that the length of the root canal could not be determined by ERCLM.
To determine the influence of frequent removable partial denture (RPD) wearing on the alveolar bo... more To determine the influence of frequent removable partial denture (RPD) wearing on the alveolar bone density changes around the abutment teeth. Fifty examinees of both genders, wearing partial dentures, were included in the study. Thirty one of the examinees (62%) were wearing the dentures 24 hours a day, while nineteen (34%) of them were wearing them only during the day. The changes in the bone density around the abutment teeth were determined by the intraoral microdensitometry method. Standard retroalveolar radiographs were performed twice. The first one before the removable partial denture delivery and the second one after a period of three-month denture wearing. A copper step wedge consisting of five steps (0.1-0.5 mm) was attached to the radiograph in order to calibrate it. Seven points, regions of interest (ROI) close to the root of the abutment tooth, all ten pixels in size, were selected on each radiograph. Grey areas in the regions of interest were measured and converted into the copper step wedge thickness equivalents in order to estimate the change in the alveolar bone density and measure the difference in alveolar bone density between two radiographs. The results indicated that there is not any statistically relevant change (t-value less than 2,011; t(49,0.05) / F less than 4,0426; F0.05(1,48)) in the alveolar bone density depending on the frequency of removable partial denture wearing. The frequency of removable partial denture wearing does not cause any changes in the alveolar bone density around the abutment teeth in the period of three-month denture wearing.
This study aimed to investigate the individual effects of chronic stress and occlusal interferenc... more This study aimed to investigate the individual effects of chronic stress and occlusal interference, as well as their combined influence on masseter muscle pain. Experiments were performed on 28 male Wistar rats. Animals were submitted to chronic stress procedure, exposed to occlusal interference, or exposed to both mantioned procedures. At the end of the procedure animals were submitted to orofacial formalin test, and nociceptive behavioral response was evaluated. Statisticaly significant difference of nociceptive behavioral response in chronicaly stressed rats and in the animals with occlusal interference in comparation to the control group were not obtained (p > 0.05). In contrast, nociceptive behavioral response was significantly increased in rats submitted to both of experimental procedures (p < 0.01). These findings suggest that only combination of occlusal interference and chronic stress influence masseter muscle pain.
To determine the changes in surface gloss of different composite materials after simulation of me... more To determine the changes in surface gloss of different composite materials after simulation of mechanical and chemical aging mechanisms. 36 specimens were fabricated for each material and polished with 120-, 220-, 500-, 1200-, 2400- and 4000- grit SiC abrasive paper, respectively. Gloss measurements were made with a glossmeter (Novo-Curve) prior to testing procedures. Specimens of each material were randomly divided into three groups. Group 1 was conditioned for 7 days at 37 degrees C in 75% ethanol aqueous solution. Group 2 was immersed in fluoride gel (Elmex Gelée) at 37 degrees C for 1 hour. Group 3 was subjected to simulated toothbrushing with an electric toothbrush while being immersed in toothpaste. Surface gloss measurements were made subsequently. Significant difference between surface gloss of the composite materials tested were detected after simulated brushing (Kruskal Wallis, P < 0.05). With the exception of Filtek Silorane, all composite materials tested were signifi...
The aim of this study was to examine the importance of a transitional ion concentration zone at t... more The aim of this study was to examine the importance of a transitional ion concentration zone at the apical foramen during electronic root canal length measurement (ERCLM). The model comprised 21 extracted single-rooted human teeth, divided into two experimental groups and one control group, each of seven teeth. The anatomical tooth length was determined from the site of reference on the tooth crown to the canal orifice and was measured using an endodontic file and a vernier caliper. Two aqueous solutions of various NaCl, KCl and CaCl2 concentrations were mixed with agar. The Na+, K+ and Ca++ concentrations corresponded to the average value of each group as determined by atomic spectrophotometry evaluation of the extirpated human pulps. The agar containing cations was injected into the root canals after their preparation to a foramen diameter of 0.70 mm. The control teeth were then completely immersed in agar having the same concentration of cations as the agar inside the canal. In the first experimental group (group 1), the teeth were immersed in agar so that the ion concentration was higher inside the canal; in the second experimental group (group 2), the concentrations were reversed. In all three groups, ERCLM was performed by an EED 11--resistance type device. Length d1 was defined as the length of the root when measured to a value one degree less than the test value. Length d2 was defined as the length of the root inducted by the test value, which corresponded to the resistance of the periapical agar. In group 1 the average d1 length was 0.44 +/- 1.05 shorter than the anatomical foramen (AF), and in group 2, 1.11 +/- 0.43 mm longer than AF. In the control group the d1 length was on average--3.02 +/- 3.72 mm from the AF. The d1 values of all groups were not statistically significantly different from the anatomical length (AL). In all three experimental groups the d2 length was statistically significantly different from the AL (P &lt; 0.05, t-test); group 1 d2 = AL + 6.32 +/- 1.38 mm; group 2 d2 = AL + 6.27 +/- 1.47; control group d2 = AL + 9.15 +/- 1.00 mm. The results of this study indicated that when the electroconductive medium in the canal had a different ion concentration than the periapex, and the canal orifice had a wide diameter (0.70 mm), the transitional concentration zone influenced the accuracy of measurement during ERCLM with a resistance type device. When ion concentrations inside and outside the canal were identical, in teeth with a wide foramen diameter (0.70 mm or more) the lack of a transitional ion concentration zone meant that the length of the root canal could not be determined by ERCLM.
To determine the influence of frequent removable partial denture (RPD) wearing on the alveolar bo... more To determine the influence of frequent removable partial denture (RPD) wearing on the alveolar bone density changes around the abutment teeth. Fifty examinees of both genders, wearing partial dentures, were included in the study. Thirty one of the examinees (62%) were wearing the dentures 24 hours a day, while nineteen (34%) of them were wearing them only during the day. The changes in the bone density around the abutment teeth were determined by the intraoral microdensitometry method. Standard retroalveolar radiographs were performed twice. The first one before the removable partial denture delivery and the second one after a period of three-month denture wearing. A copper step wedge consisting of five steps (0.1-0.5 mm) was attached to the radiograph in order to calibrate it. Seven points, regions of interest (ROI) close to the root of the abutment tooth, all ten pixels in size, were selected on each radiograph. Grey areas in the regions of interest were measured and converted into the copper step wedge thickness equivalents in order to estimate the change in the alveolar bone density and measure the difference in alveolar bone density between two radiographs. The results indicated that there is not any statistically relevant change (t-value less than 2,011; t(49,0.05) / F less than 4,0426; F0.05(1,48)) in the alveolar bone density depending on the frequency of removable partial denture wearing. The frequency of removable partial denture wearing does not cause any changes in the alveolar bone density around the abutment teeth in the period of three-month denture wearing.
This study aimed to investigate the individual effects of chronic stress and occlusal interferenc... more This study aimed to investigate the individual effects of chronic stress and occlusal interference, as well as their combined influence on masseter muscle pain. Experiments were performed on 28 male Wistar rats. Animals were submitted to chronic stress procedure, exposed to occlusal interference, or exposed to both mantioned procedures. At the end of the procedure animals were submitted to orofacial formalin test, and nociceptive behavioral response was evaluated. Statisticaly significant difference of nociceptive behavioral response in chronicaly stressed rats and in the animals with occlusal interference in comparation to the control group were not obtained (p > 0.05). In contrast, nociceptive behavioral response was significantly increased in rats submitted to both of experimental procedures (p < 0.01). These findings suggest that only combination of occlusal interference and chronic stress influence masseter muscle pain.
Uploads