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Acta Odontol Scand [journal]
- Influence of successive light-activation on degree of conversion and knoop hardness of the first layered composite increment. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Oct 14.:1-6.
Abstract Purpose: To evaluate the influence of light-activation of second, third and fourth increments on degree of conversion (DC) and microhardness (KHN) of the top (T) and bottom (B) surface of the first increment. Materials and methods. Forty samples (n = 5) were prepared. In groups 1-4, after each increment light-activation (multiple irradiation), T and B of the first increment were measured in DC and KHN. In groups 5-8, only the first increment was made (single irradiation) and measurements of DC and KHN were taken at 15 min intervals. The light-activation modes were (XL) 500 mW/cm(2) × 38 s (G1/G5); (S) 1000 mW/cm(2) × 19 s (G2/G6), (HP) 1400 mW/cm(2) × 14 s (G3/G7); (PE) 3200 mW/cm(2) × 6 s (G4/G8). Data for DC and KHN were analyzed separately by using PROC MIXED for repeated measures and Tukey-Kramer test (α = 0.05). Results. For KHN, B showed lower values than T. PE resulted in lower values of KHN in B surface. For single and multiple irradiations, T and B of first measurement showed the lowest KHN and the fourth measurement showed the highest, with significant difference between them. For single irradiation, first and second increments presented similar KHN, different from the third and fourth increment, which did not differ between them. For multiple irradiations, the second light-activation resulted in KHN similar to first, third and fourth increments. For DC, except QTH, T presented higher DC than B. Conclusion. The light-activation of successive increments was not able to influence the KHN and DC of the first increment.
- Applicability of the Demirjian method for dental age estimation in western Turkish children. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Oct 14.:1-5.
Abstract Objective. The aim of this study was to examine whether the Demirjian method would be appropriate for estimation of the dental age of western Turkish children. Materials and methods. This study comprised 635 Turkish children (age = 7-16 years) from the western Aegean region who were chosen on the basis of radiological evidence from digital orthopantomograms. Their dental maturity was evaluated according to the stages proposed by Demirjian. A paired t-test was used for statistical analysis. Results. The mean difference between the chronological and dental ages ranged from 0.10-0.76 years for males and from 0.28-0.87 years for females. Conclusion. The applicability of the Demirjian method is not suitable for western Turkish children and western Turkish children have a lower degree of dental maturity than that observed in the eastern, northeastern and northern Turkish subjects.
- Normative and self-perceived orthodontic treatment need in Nigerian school children. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Oct 14.:1-4.
Abstract Objective. The aim of this study was to assess the normative and self-perceived need for orthodontic treatment in Nigerian children, and to evaluate distribution of orthodontic treatment need according to gender and age. Materials and methods. The sample consisted of 441 randomly selected school children, aged 11-18 years in Benin City, Nigeria. The subjects were further sub-grouped according to gender (229 males and 212 females) and age (246 11-13 years old and 195 14-18 years old). The Dental health Component (DHC) and Aesthetic Component (AC) of Index of Orthodontic Treatment Need (IOTN) were used to assess orthodontic treatment need normatively. Self-perceived need was evaluated by asking the subjects to rate their dental aesthetics on the Aesthetic Component scale of IOTN. Chi-square tests were used to evaluate gender and age differences in distribution of treatment need. Results. A definite need for orthodontic treatment was found among 21.5% (grades 4-5 of DHC) and 6.3% (grades 8-10 of AC) of the subjects; 3.9% of the subjects perceived a definite need for orthodontic treatment (grades 8-10 of AC). There were no statistically significant gender and age differences in distribution of orthodontic treatment need among the subjects (p > 0.05). Conclusion. The study revealed a need for orthodontic treatment in slightly more than one fifth (21.5%) of this sample of Nigerian children. The sample population has a lower need on aesthetic grounds and their normative and self-perceived orthodontic treatment needs were not influenced by gender and age.
- A comparison of the fitting accuracy of thermoplastic denture base resins used in non-metal clasp dentures to a conventional heat-cured acrylic resin. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Oct 14.:1-5.
Abstract Objective. To incorporate a metal framework into removable partial dentures, the dimensional accuracy of thermoplastic resins requires precision equivalent to conventional acrylic resins. This study aimed to evaluate the fitting accuracy of thermoplastic resins compared to heat-cured acrylic resin. Materials and methods. Four thermoplastic resins (polyethylene terephthalate [EstheShot, ES; EstheShot Bright, ES-B], polyamide [Lucitone FRS, LF], polycarbonate [Reigning Resin N, RN] and a heat-curing acrylic resin [Acron, AC]) were used. The specimens were created on master casts constructed of high-strength stone that simulated a maxillary edentulous ridge. Additionally, high-expansion stone was used as the master cast for RN specimens. The ES-B, LF and RN specimens were prepared with and without annealing after injection molding. The gaps between the molded resin and the cast were measured. Results. ES had the smallest gap and was significantly smaller than AC (p < 0.05). The gap sizes of ES-B, LF and RN (high-expansion stone) without annealing were similar to AC (p > 0.05), while the gap size of RN (high-strength stone) with and without annealing was significantly greater than AC (p < 0.001). The gap sizes of ES-B and LF with annealing were significantly less than AC (p < 0.05). Further, the gap sizes of ES-B, LF and RN with annealing were significantly smaller than the gaps without annealing (p < 0.05). Conclusions. The results suggested that ES, ES-B and LF have adequate fitting accuracy for incorporating metal framework into dentures and that annealing effectively improved the fitting accuracy of ES-B, LF and RN.
- Influence of preparation design on fit and ceramic thickness of CEREC 3 partial ceramic crowns after cementation. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Oct 9.:1-7.
Abstract Objective. This study investigated the influence of preparation design on the marginal and internal gap and ceramic thickness of partial ceramic crowns (PCCs) fabricated with the CEREC 3 system. Materials and methods. Sixteen extracted human mandibular molars were prepared according to two different preparation designs (n = 8): a retentive preparation design with traditional cusp capping (Group I) and a non-retentive preparation design with horizontal reduction of cusps (Group II). PCCs were fabricated from IPS Empress CAD with the CEREC 3 system. The parameters for luting space and minimum occlusal ceramic thickness were set to 30 μm and 1.5 mm, respectively. The fabricated PCCs were cemented to their corresponding teeth with self-adhesive resin cement and were then scanned by micro-computed tomography. The marginal and internal gaps were measured at pre-determined measuring points in five bucco-lingual and three mesio-distal cross-sectional images. The ceramic thicknesses of the PCCs were measured at the measuring points for cusp capping areas. Results. Group II (167.4 ± 76.4 μm) had a smaller overall mean gap, which included the marginal and internal gap measurements, than that of Group I (184.8 ± 89.0 μm). The internal gaps were larger than the marginal gaps, regardless of preparation design. Group I presented a thinner ceramic thickness in the cusp capping areas than the minimum occlusal ceramic thickness parameter of 1.5 mm. Conclusion. Preparation design had an influence on fit, particularly the internal gap of the PCCs. Ceramic thickness could be thinner than the minimum ceramic thickness parameter.
- Influence of tooth length on the accuracy of the Root ZX electronic apical foramen locator: An ex vivo study. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Oct 9.:1-6.
Abstract Objective. Electronic apical foramen locators are now widely used to determine working length. This study was designed to determine whether tooth length influenced the accuracy of the Root ZX device. Materials and methods. Forty extracted maxillary canine teeth with a length range of 27-29 mm were selected. Access cavities were prepared and coronal flaring of canals performed. The teeth were mounted in self-polymerizing acrylic resin to facilitate horizontal sectioning except for the apical 3-4-mm portion of the root and embedded in alginate as the electronic medium. Electronic measurements were taken at the major foramen, 'zero' reading using the Root ZX and compared with the actual root canal length. The teeth were sectioned 3 mm from the coronal reference point to create a second group with shorter length; these reductions in the length continued six times in all to create seven groups of 40 specimens each. The actual and electronic lengths of specimens in each group were measured. Data were analyzed by Pearson's correlation coefficient. Results. Identical measurements between the actual and electronic root canal length from the longest to the shortest groups were 12.5%, 10.0%, 20.0%, 27.5%, 37.5%, 35.0% and 45.0%, respectively. There was a mild negative correlation between the precise measurements of the Root ZX and root canal lengths in the seven groups (r = -0.964, p < 0.001). Conclusion. Under the conditions of the study, the Root ZX device was more accurate in shorter teeth compared to longer ones.
- Quantitative microleakage analysis of endodontic temporary filling materials using a glucose penetration model. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Sep 25.:1-7.
Abstract Objective. The purpose of this study was to analyze the sealing ability of different temporary endodontic materials over a 6-week period using a glucose penetration model. Materials and methods. Standardized holes were formed on 48 dentin discs from human premolars. The thicknesses of the specimens were distributed evenly to 2 mm, 3 mm and 4 mm. Prepared dentin specimens were randomly assigned into six groups (n = 7) and the holes in the dentin specimens were filled with two kinds of temporary filling materials as per the manufacturers' instructions as follows: Caviton (GC Corporation, Tokyo, Japan) 2 mm, 3 mm, 4 mm and IRM (Dentsply International Inc., Milford, DE) 2 mm, 3 mm, 4 mm. The remaining specimens were used as positive and negative controls and all specimens underwent thermocycling (1000; 5-55°C). The sealing ability of all samples was evaluated using the leakage model for glucose. The samples were analyzed by a spectrophotometer in quantitative glucose microleakage test over a period of 6 weeks. As a statistical inference, a mixed effect analysis was applied to analyze serial measurements over time. Results. The Caviton groups showed less glucose penetration in comparison with the IRM groups. The Caviton 4 mm group demonstrated relatively low glucose leakage over the test period. High glucose leakage was detected throughout the test period in all IRM groups. The glucose leakage level increased after 1 week in the Caviton 2 mm group and after 4 weeks in the Caviton 3 mm and 4 mm groups (p < 0.05). Conclusions. Caviton had better sealing ability than IRM in the glucose penetration model during 6 weeks. Temporary filling of Caviton to at least 3 mm in thickness is necessary and temporary filling periods should not exceed 4 weeks.
- Trauma from instrumentation after non-surgical periodontal treatment with ultrasonic scalers and Nd:YAG laser. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Sep 25.:1-6.
Abstract Objective. Periodontal therapies aimed at altering the progression of periodontal diseases must include meticulous mechanical debridement during both the non-surgical and the surgical phases of periodontal treatment. The aim of this study was to evaluate and compare the immediate effect of trauma from instrumentation on clinical attachment level after non-surgical periodontal treatment with ultrasonic scalers and a Nd:YAG laser. Materials and methods. Twenty-four patients with untreated chronic periodontitis, presenting probing depths of 4-6 mm on anterior teeth, upper and lower, were entered into the study. The selected teeth were probed with a pressure-controlled probe, guided by stents. Each quadrant was randomly allocated in a split-mouth design either to treatment with Nd:YAG laser using an energy of 1W, 100mj, 1064nm (test group) or to periodontal treatment using ultrasonic scalers (control group). Clinical parameters, including plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD) and probing attachment level (PAL) were acquired prior to and immediately after treatment. Results. Statistical analysis demonstrated no differences between groups at baseline for all parameters (p > 0.05). Immediately after treatment, the control group showed a greater PAL loss than the test group (p < 0.05). For the control group, there were statistically significant differences between PAL immediately before and after treatment (p < 0.05), but not test group (p > 0.05). Conclusions. Within the limits of the present study, it may be concluded that non-surgical periodontal treatment with ultrasonic scalers causes a mean immediate attachment loss of 0.68 mm and that a Nd:YAG laser seems to reduce significantly the trauma the instrumentation produced.
- Oral health and apraxia among institutionalized elderly people-A pilot study. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Sep 25.:1-6.
Abstract Objective. Poor oral hygiene and dental health are very common among the institutionalized elderly. The purpose of this study was to evaluate the association of apraxia with oral hygiene and/or health. Materials and methods. Ninety-two residents of 13 long-term care homes in southwest Germany participated in the study. For each participant, ideomotor apraxia scoring (AS) was conducted and demographic variables were collected. Participants underwent a comprehensive dental examination to assess the oral health indices gingival bleeding index (GBI), community periodontal index of treatment needs (CPITN) and denture hygiene index (DHI). Statistical comparison of dental indices among apraxic and non-apraxic individuals (cut-off < 45) was performed by use of t-tests. In addition, linear regression models were constructed with the dental indices as dependent variables. Each model was fitted with the dichotomized variable AS (pathologic or healthy) and adjusted for age and sex. Results. Mean (SD) GBI of 48.5 (25.9), CPITN of 2.9 (0.7) and DHI of 82.6 (14.6) were observed among the participants. Statistical analysis revealed AS was significantly associated with all oral health indicators (p < 0.05). Linear regression models showed apraxia is a predictor of GBI (p = 0.002) and CPITN (p = 0.027), but not of denture hygiene (p = 0.916). Conclusions. Although this pilot investigation has limitations, the results suggest the presence of apraxia should be considered when planning oral healthcare strategies. Further research with larger samples is encouraged to confirm these relationships.
- Interleukin 1β (+3954, -511 and -31) polymorphism in chronic periodontitis patients from North India. [JOURNAL ARTICLE]
- Acta Odontol Scand 2014 Sep 25.:1-5.
Abstract Objective. Several studies have implicated the role of interleukin-1 in various chronic diseases including periodontitis. The present study was carried out with an aim to evaluate the role of interleukin 1β polymorphisms, namely +3954C/T, -511C/T and -31T/C, in the development of chronic periodontitis. Materials and methods. Twenty-nine chronic periodontitis patients and 31 healthy controls of North Indian origin from Chhattisgarh were recruited for the study. The genotypes for the three variants were determined using the PCR-RFLP technique and the strength of association between genotypes and periodontitis was determined by odds ratio with 95% confidence interval (CI) and chi-square analysis. Results. Analysis for the +3954 allelic and genotypic frequencies of the polymorphism revealed a significant difference in the CT genotype between periodontitits patients and controls (p = 0.03). A significant difference was also observed in the allelic frequencies between the two groups (p = 0.02). For the -511 site, TT genotype revealed a significant association with the disease (p = 0.01). A significant association was also found following the co-dominant model (p = 0.007). However, the -31 polymorphism revealed no significant difference between patients and controls. Conclusions. In conclusion, the present study suggests a strong association of the TT genotype of -511 and CT genotype of +3954 variant of interleukin 1β with chronic periodontitis. However, the -31 variant did not show a significant association with the disease.