Comparison of Orthodontic Root Resorption of Root-filled and Vital Teeth Using Micro–computed Tomography

ObjectiveTo evaluate the difference in orthodontic root resorption between root-filled and vital teeth.Material and MethodsSixteen individuals who required bilateral premolar tooth extraction due to orthodontic treatment and had a previously root-filled premolar tooth on one side were included in the study. The experimental group consisted of root-filled premolar teeth, and the control group consisted of contralateral vital premolar teeth. A 150-g buccally directed force was applied to these teeth using 0.017 × 0.025-inch TMA cantilever springs. The premolars were extracted 8 weeks after the application of force. Images were obtained using micro–computed tomography. Resorption measurements were obtained using the Image J program.ResultsThe mean values for resorption were 0.08869 mm³ for the root-filled teeth and 0.14077 mm³ for the contralateral teeth, indicating significantly less resorption for the root-filled teeth compared with the contralateral teeth after the application of orthodontic force (P = .003). In both groups, the most resorption was seen on the cervical-buccal and apical-lingual surfaces. The mean resorption value of the cervical region was 0.06305 mm³ in the control group and 0.0291 mm³ in the experimental group, and the difference was statistically significant (P = .002).ConclusionsRoot-filled teeth showed significantly less orthodontic root resorption than vital teeth.     

The cellular immunity and oxidative stress markers in early pregnancy loss

Objective: We investigated whether changes in cellular immunity and oxidative stress in pregnancy have any association with spontaneous miscarriage.

Material and methods: Circulating adenosine deaminase (ADA) activity as a marker of cellular immunity and malondialdehyde (MDA) and catalase (CAT), glutathione peroxidase (GPx) as markers of T lymphocyte activation and parameters of oxidative stress and antioxidant defense were compared between 40 women with early pregnancy loss and another 40 women with ungoing healthy pregnancy.

Results: Women with miscarriage had higher serum ADA and GPx levels when compared with women with normal pregnancy (p?=?0.034 and p?<?0.001, respectively). Although serum MDA level was slightly higher in women with miscarriage, the difference was not significant (p?=?0.083). CAT levels were alike in both groups.

Conclusion: We have demonstrated an increased cellular immunity and perhaps a compensated oxidative stress related to increased antioxidant activation in women with early spontaneous pregnancy loss.     

A comparison between zinc polycarboxylate and glass ionomer cement in the orthodontic band cementation

Fixed orthodontic appliances have been held responsible for demineralization and caries since the time they were first introduced. Zinc polycarboxylate and glass ionomer cements are the primary materials used in band cementing. In this study, we evaluated the re-cementing frequencies, enamel demineralization and the degree of cement remains of the bands cemented with glass ionomer and zinc polycarboxylate cements. We have concluded that given the retentive properties and enamel decalcification degree, the glass ionomer cements are to be preferred by the orthodontist.     

Two-year color changes of light-cured composites: influence of different light-curing units

This study determined color changes in a composite cured with various types of curing units after two years. A hybrid (Clearfil AP-X) composite was cured with a conventional halogen, a high intensity halogen, a plasma arc and a light emitting diode unit. The specimens were stored in light-proof boxes after the curing procedure to avoid further exposure to light and stored in 37 degrees C in 100% humidity. Colorimetric values of the specimens immediately after curing and after two years were measured using a colorimeter. The CIE 1976 L*a*b color system was used to determine color differences. Differences from baseline were calculated as deltaE*ab. Data were analyzed with two-way analysis of variance (p<0.05). The deltaE*ab values varied significantly, depending on the curing unit used. The specimens cured with a plasma arc curing unit induced significantly higher color changes than any other specimen and the color differences were also visually appreciable by the non-skilled operator (deltaE*ab >2.5). The specimens cured with a high intensity halogen curing unit produced the lowest color change; however, there were no statistically significant differences among the color changes of specimens cured with conventional halogen, high intensity halogen and the light emitting diode unit, and the color changes were not clinically relevant (deltaE*ab <2.5). The results of this study suggest that composite materials undergo measurable changes due to curing unit exposure. The specimens cured with a plasma arc light showed the highest color changes as compared to specimens cured with other curing units.     

Temperature increase during resin cement polymerization under a ceramic restoration: effect of type of curing unit

PURPOSE: This study measured the temperature increase induced by various types of curing units during resin cement polymerization under ceramic restorations. MATERIALS AND METHODS: The resin cement was polymerized between a ceramic specimen (diameter 5 mm, height 2 mm) and a dentin disk (diameter 5 mm, height 1 mm) with a conventional halogen light, a high-intensity halogen light, a plasma-arc light, and a light-emitting diode unit. The temperature increase was measured under the dentin disk with a J-type thermocouple wire connected to a data logger. Ten measurements were carried out for each curing unit. Difference between starting and highest temperature readings was measured, and the 10 calculated temperature changes were averaged. RESULTS: Temperature increase varied significantly depending on curing unit used. The plasma-arc light induced significantly higher temperature increases than any other curing unit. The light-emitting diode unit produced the lowest temperature changes. There were no statistically significant differences between the conventional and high-intensity halogen curing units. CONCLUSION: Polymerization with curing units characterized by high energy output (plasma-arc light) caused higher temperature changes compared to other curing units, but the temperature increase detected was not viewed as critical for pulpal health.     

The effect of ceramic thickness and number of firings on the color of ceramic systems: an in vitro study

STATEMENT OF PROBLEM: Although all-ceramic restorations are widely used, there is a lack of information on how color is affected by fabrication procedures. Color matching problems may be encountered in a definitive restoration despite careful shade selection. PURPOSE: The aim of this study was to evaluate the effect of dentin ceramic thickness and repeated firings on the color of glass-infiltrated aluminum-oxide (In-Ceram) and leucite-reinforced (IPS Empress) all-ceramic systems using a colorimeter. MATERIAL AND METHODS: Twenty-one disc-shaped specimens, 10 mm in diameter with a 0.6-mm core thickness and 0.5-, 1-, or 1.5-mm dentin ceramic thickness, were made from each of 2 ceramic systems (n=7) . Repeated firings were performed for each group, and the color differences were compared with the color after the initial firing. Color differences among ceramic specimens were measured using a colorimeter (XL-20 Colorimeter), and data were expressed in Commission Internationale d'Eclairage (CIE) LAB system coordinates. Repeated-measures analysis of variance was used to analyze the data (number of firings, ceramic brand, and ceramic thickness) for significant differences. The Tukey honestly significant difference test and paired 2-tailed tests were used to perform multiple comparisons (alpha=.05). RESULTS: The L( *)a( *)b( *) values of ceramic systems were affected by the number of firings (3, 5, or 7) (P<.01) and ceramic brand (In-ceram or IPS Empress) (P<.01). L( *) and a( *) values were affected by ceramic thickness (0.5, 1, or 1.5 mm) (P<.01); however, b( *) value was not affected by ceramic thickness (P=.075). Significant interactions were present in L( *), a( *), b( *) values between number of firings and ceramic brand (P<.01), and between ceramic brand and ceramic thickness (P<.05). Significant interactions were present between number of firings and ceramic thickness (P<.01) in L( *) and b( *) values but not in the a( *) value (P=.379). CONCLUSION: The analysis revealed that there were substantial changes in L( *)a( *)b( *) color data as the number of firings increased, which resulted in perceptual color changes in L( *)a( *)b( *) color parameters.     

Effect of oral citicoline therapy on retinal nerve fiber layer and ganglion cell-inner plexiform layer in patients with primary open angle glaucoma

AIM: To evaluate the short-term effects of oral citicoline therapy on the retinal nerve fiber layer (RNFL) and the macular ganglion cell-inner plexiform layer (mGCIPL) in patients with primary open angle glaucoma (POAG). METHODS: Fifty-four eyes of 54 patients with POAG glaucoma included in the study. In addition to a topical hypotensive, 250-mg oral citicoline was administered to 27 patients, while 27 patients were assigned as the control group. RNFL and mGCIPL values were measured using optical coherence tomography (OCT) at 1d before treatment and 3mo after the initiation of treatment. At the third month visit, citicoline treatment was discontinued and drug-free control (wash-out) measurements were obtained at the fourth month in citicoline group. RESULTS: The average RNFL thickness was significantly higher at month 3 than the baseline (P=0.038) in citicoline group. However, this improvement partially regressed after a 1-month wash-out period. No statistically significant changes in RNFL were observed in the superior, nasal, temporal and inferior quadrants at months 3 and 4 (P>0.05). The change in the average and inferior quadrant RNFL thickness in the citicoline group at 3mo was significantly greater than the control group (P=0.006 and P=0.014, respectively). There were no significant differences between the groups according to the change in mGCIPL thickness and the superior, nasal and temporal quadrant RNFL thickness (P>0.05). CONCLUSION: With oral citicoline treatment, the loss in the average RNFL is prevented in POAG patients in the short-term. Study data show that citicoline may have a significant impact on slowing glaucoma progression, which could have a potential neuroprotective effect.     

Conservative approach for restoring posterior missing tooth with fiber reinforcement materials: four clinical reports

Adhesively luted, fiber-reinforced, composite-inlay, retained fixed-partial dentures can be a clinical alternative for the replacement of missing posterior teeth in selective situations. This type of restoration allows for satisfactory esthetics and reduced tooth preparation compared to a conventional, fixed-partial denture. This clinical report describes the use of a fiber-reinforced, composite-inlay, retained fixed-partial denture as a conservative alternative for the replacement of missing posterior teeth.     

Factors associated with increased carotid intima-media thickness and being nondipper in nonobese and normotensive young patients affected by PCOS

Polycystic ovary syndrome (PCOS) is characterized by chronic unovulation, hyperandrogenism, and insulin resistance. We evaluated factors that affect "nondipper" status during 24-hour ambulatory blood pressure monitoring (ABPM) and carotid intima-media thickness (cIMT) in PCOS. Forty-two nonobese women newly diagnosed as PCOS and 32 healthy women were included. After biochemical and hormonal measurements, the ovaries were imaged by pelvic ultrasonography and cIMT was measured by B-mode ultrasonography. A 24-hour ABPM was performed thereafter. Carotid IMT and the ratio of nondippers were elevated compared with controls. Homeostasis model assessment insulin resistance index (HOMA-IR) and low-density lipoprotein cholesterol (LDL-C) were found to be related with being a nondipper in PCOS. None of the parameters evaluated were found to correlate with cIMT. In conclusion, patients with PCOS had increased nondipping ratios and cIMT when compared with controls. Insulin resistance and LDL cholesterol are factors that are related to diurnal variation in normotensive and young patients with PCOS.