ISRN Dentistry[JOURNAL]
Sun
137 papers
Dental maturity in saudi children using the demirjian method: a comparative study and new prediction models.
Baghdadi ZD
ISRN Dent · 2013 · PMID 23533790 · Full text
A sample of 422 dental panoramic radiographs from individuals of known age (from 4 to 14 yrs), sex (males: 217, females: 205), and ethnicity (Saudi) was collected. A dental maturation score for each individual was calcul...
A sample of 422 dental panoramic radiographs from individuals of known age (from 4 to 14 yrs), sex (males: 217, females: 205), and ethnicity (Saudi) was collected. A dental maturation score for each individual was calculated using the Demirjian method. Age was then estimated using the original Demirjian curves and tables based on French-Canadian population and population-specific curves and tables for Arab (Saudi and Kuwaiti) and European (Belgian) populations. The differences between dental age and chronological age were analyzed and compared using paired t-tests, one-way ANOVA test, and a post hoc Scheffé's test. The Demirjian method utilizing French-Canadian standards presented significant difference between dental age and chronological age for the total sample and in the vast majority of age groups in both sexes. The mean overestimation of age was about 10 months (P < 0.05). The tables designed specifically for Arab populations had a significantly lower error than the tables designed for French-Canadian and Belgian populations. The latter had the largest error in age predication. New age prediction models and maturation scores for Saudi population were developed based on the Demirjian method using multinomial functions.
Biocompatibility of intracanal medications based on calcium hydroxide.
Andolfatto C, da Silva GF, Cornélio AL … +5 more , Guerreiro-Tanomaru JM, Tanomaru-Filho M, Faria G, Bonetti-Filho I, Cerri PS
ISRN Dent · 2012 · PMID 23320187 · Full text
Objective. The aim of this study was to evaluate the rat subcutaneous tissue reaction to calcium hydroxide-based intracanal medicaments, UltraCal XS (calcium hydroxide, barium sulphate, aqueous matrix), Hydropast (calciu...
Objective. The aim of this study was to evaluate the rat subcutaneous tissue reaction to calcium hydroxide-based intracanal medicaments, UltraCal XS (calcium hydroxide, barium sulphate, aqueous matrix), Hydropast (calcium hydroxide, barium sulphate, and propyleneglycol), and Calen (Calcium hydroxide, zinc oxide, colophony, and polyethyleneglycol), used as a control. Methods. Forty-eight rats (Rattus Norvegicus Holtzman) were distributed in three groups: Calen, UltraCal XS, and Hydropast. Polyethylene tubes filled with one of the medicaments were implanted in the dorsal subcutaneous. After 7 and 30 days, the implants were removed and the specimens were fixed and embedded in paraffin. Morphological and quantitative analyses were carried out in the HE-stained sections. The numerical density of inflammatory cells in the capsule was evaluated and statistical analyses were performed (P ≤ 0.05). Results. At 7 days, all materials induced an inflammatory reaction in the subcutaneous tissue adjacent to the implants. In all groups, a significant reduction in the number of inflammatory cells and giant cells was verified in the period of 30 days. Conclusion. These results indicate that the calcium hydroxide-based medicaments evaluated present biocompatibility similar to Calen.
Dimensional accuracy of stone casts obtained with multiple pours into the same mold.
Valente Vda S, Zanetti AL, Feltrin PP … +3 more , Inoue RT, de Moura CD, Pádua LE
ISRN Dent · 2012 · PMID 23320186 · Full text
Aim. The aim of the present study was to compare the dimensional accuracy of stone casts obtained with vinyl polysiloxane molds through the double-impression technique with three pours into the same mold. Methods. A stai...
Aim. The aim of the present study was to compare the dimensional accuracy of stone casts obtained with vinyl polysiloxane molds through the double-impression technique with three pours into the same mold. Methods. A stainless steel master model was constructed simulating a three-unit fixed prosthesis. Twelve impressions were taken of this master model with addition silicone, using the double-impression technique. Three pours of type IV gypsum were then made into each mold, thus producing 36 casts. The pours were made 1 hour, 6 hours and 24 hours after the impression procedure. Next, intra- and interabutment measurements were made in a coordinate measuring machine. Results. Comparative analysis of the dimensional accuracy of stone casts resulting from multiple pours was not statistically significant in pours first and second (P > 0.05). These values, however, were statistically significant at third pour in the height in abutment 1 and upper distance interabutment. Conclusion. The wait time (1 hour, and 6 hours) observed before pouring the stone into the same molds did not cause significant dimensional accuracy of the casts.
Temperature Rise during Primer, Adhesive, and Composite Resin Photopolymerization of a Low-Shrinkage Composite Resin under Caries-Like Dentin Lesions.
Mousavinasab SM, Khoroushi M, Moharreri M
ISRN Dent · 2012 · PMID 23320185 · Full text
Objective. This study evaluated temperature rise of low-shrinkage (LS) self-etch primer (P), LS self-etch adhesive (A), and P90 silorane-based composite resin systems, photopolymerized under normal and artificially demin...
Objective. This study evaluated temperature rise of low-shrinkage (LS) self-etch primer (P), LS self-etch adhesive (A), and P90 silorane-based composite resin systems, photopolymerized under normal and artificially demineralized dentin. Methods. Forty 1.5 mm-thick dentin discs were prepared from sound human molars, half of which were demineralized. Temperature rise was measured during photopolymerization using a K-type thermocouple under the discs: 10 s and 40 s irradiation of the discs (controls/groups 1 and 2); 10 s irradiation of primer (P), 10 s irradiation of adhesive (A), 40 s irradiation of P90 without P and A, and 40 s irradiation of P90 with P and A (groups 3 to 6, resp.). The samples were photopolymerized using an LED unit under 550 mW/cm(2) light intensity. Data was analyzed using repeated measures ANOVA and paired-sample t-test (α = 0.05). Results. There were no significant differences in temperature rise means between the two dentin samples for each irradiation duration (P > 0.0001), with significant differences between the two irradiation durations (P > 0.0001). Temperature rise measured with 40 s irradiation was significantly higher than that of 10 s duration for undemineralized and demineralized dentin P < 0.0001). Conclusions. Light polymerization of P90 low-shrinkage composite resin resulted in temperature rise approaching threshold value under artificially demineralized and undemineralized dentin.
Evaluation of the periodontal status in acromegalic patients: a comparative study.
Harb AN, Holtfreter B, Friedrich N … +3 more , Wallaschofski H, Nauck M, Kocher T
ISRN Dent · 2012 · PMID 23304536 · Full text
Aim. The aim was to compare the periodontal status of the acromegalic patients with healthy subjects from a large population-based cohort (Study of Health in Pomerania, SHIP). Materials and Methods. We studied 32 acromeg...
Aim. The aim was to compare the periodontal status of the acromegalic patients with healthy subjects from a large population-based cohort (Study of Health in Pomerania, SHIP). Materials and Methods. We studied 32 acromegalic patients (16 females) and 128 randomly selected SHIP subjects (controls) using a 1 : 4 matching. Serum IGF-I and IGFBP-3 levels were measured using the Immulite 2500 system. Periodontitis was assessed by clinical attachment loss (CAL), probing depth (PD), and number of missing teeth. Linear and logistic regression models were used to assess differences in periodontal variables between acromegalic patients and controls. Results. IGF-I levels were comparable in acromegalic patients and controls, whereas IGFBP-3 levels were significantly higher in acromegalic patients (P = 0.004). In multivariate modelling, both groups did not differ significantly with respect to mean CAL (P = 0.12) and high tooth loss (P = 0.36). Mean PD was higher in acromegalic patients by trend (B = 0.28 (-0.00; 0.56)). Conclusion. In acromegalic patients, periodontal disease severity did not differ from their healthy SHIP controls.
Accuracy of four tooth size prediction methods on malay population.
Mahmoud BK, Abu Asab SH, Taib H
ISRN Dent · 2012 · PMID 23209918 · Full text
Objective. To examine the accuracy of Moyers 50%, Tanaka and Johnston, Ling and Wong and Jaroontham and Godfrey methods in predicting the mesio-distal crown width of the permanent canines and premolars (C + P(1) + P(2))...
Objective. To examine the accuracy of Moyers 50%, Tanaka and Johnston, Ling and Wong and Jaroontham and Godfrey methods in predicting the mesio-distal crown width of the permanent canines and premolars (C + P(1) + P(2)) in Malay population. Materials and Methods. The study models of 240 Malay children (120 males and 120 females) aged 14 to 18 years, all free of any signs of dental pathology or anomalies, were measured using a digital caliper accurate to 0.01 mm. The predicted widths (C + P(1) + P(2)) in both arches derived from the tested prediction equations were compared with the actual measured widths. Results. Moyers and Tanaka and Johnston methods showed significant difference between the actual and predicted widths of (C + P(1) + P(2)) for both sexes. Ling and Wong method also showed statistically significant difference for males, however, there was no significant difference for females. Jaroontham and Godfrey method showed statistical significant difference for females, but the male values did not show any significant difference. Conclusion. For male Malay, the method proposed by Jaroontham and Godfrey for male Thai proved to be highly accurate. For female Malay, the method proposed by Ling and Wong for southern Chinese females proved to be highly accurate.
Antimicrobial or subantimicrobial antibiotic therapy as an adjunct to the nonsurgical periodontal treatment: a meta-analysis.
Moreno Villagrana AP, Gómez Clavel JF
ISRN Dent · 2012 · PMID 23150830 · Full text
The use of antibiotics in nonsurgical periodontal treatment is indicated in cases in which scaling and root planing present important limitations. However, their use is controversial due to the secondary effects associat...
The use of antibiotics in nonsurgical periodontal treatment is indicated in cases in which scaling and root planing present important limitations. However, their use is controversial due to the secondary effects associated with them and the disagreements regarding their prescription. The aim of this study is to determine the effectiveness of systemic antibiotics in the management of aggressive and chronic periodontitis. The study was based on a search of randomized, controlled clinical trials. Common data were concentrated and evaluated by means of an analysis of variance (ANOVA), and a meta-analysis of the results was performed. The meta-analysis (P < 0.05, 95% confidence interval, post hoc Bonferroni) determined that the supplementation of nonsurgical periodontal therapy with a systemic antibiotic treatment-amoxicillin with clavulanic acid and metronidazole or subantimicrobial dose doxycycline-provides statistically significant results in patients with aggressive or chronic periodontitis under periodontal treatment, whilst increasing the clinical attachment level of the gingiva and reducing periodontal probing depth.
pH and Antimicrobial Activity of Portland Cement Associated with Different Radiopacifying Agents.
Guerreiro-Tanomaru JM, Cornélio AL, Andolfatto C … +2 more , Salles LP, Tanomaru-Filho M
ISRN Dent · 2012 · PMID 23119173 · Full text
Objective. The aim of this study was to evaluate the antimicrobial activity and pH changes induced by Portland cement (PC) alone and in association with radiopacifiers. Methods. The materials tested were pure PC, PC + bi...
Objective. The aim of this study was to evaluate the antimicrobial activity and pH changes induced by Portland cement (PC) alone and in association with radiopacifiers. Methods. The materials tested were pure PC, PC + bismuth oxide, PC + zirconium oxide, PC + calcium tungstate, and zinc oxide and eugenol cement (ZOE). Antimicrobial activity was evaluated by agar diffusion test using the following strains: Micrococcus luteus, Streptococcus mutans, Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans. After 24 hours of incubation at 37°C, inhibition of bacterial growth was observed and measured. For pH analysis, material samples (n = 10) were placed in polyethylene tubes and immersed in 10 mL of distilled water. After 12, 24, 48, and 72 hours, the pH of the solutions was determined using a pH meter. Results. All microbial species were inhibited by the cements evaluated. All materials composed of PC with radiopacifying agents promoted pH increase similar to pure Portland cement. ZOE had the lowest pH values throughout all experimental periods. Conclusions. All Portland cement-based materials with the addition of different radiopacifiers (bismuth oxide, calcium tungstate, and zirconium oxide) presented antimicrobial activity and pH similar to pure Portland cement.
In Vitro Effects of External Pressure Changes on the Sealing Ability under Simulated Diving Conditions.
Stoetzer M, Ruecker M, Koch A … +5 more , Ziebolz D, Kokemüller H, Kaempf C, Gellrich NC, von See C
ISRN Dent · 2012 · PMID 23119172 · Full text
Aim. To measure and validate the permeability of pressure changes in correlation to different root filling techniques. Methods. Eighty extracted single-rooted teeth were randomly assigned to one of eight groups of ten te...
Aim. To measure and validate the permeability of pressure changes in correlation to different root filling techniques. Methods. Eighty extracted single-rooted teeth were randomly assigned to one of eight groups of ten teeth. Following standardized instrumentation and irrigation, root canal fillings were performed using either cold lateral condensation, a warm carrier-based gutta-percha obturation technique, a warm carrier-based Resilon, or warm gutta-percha compaction with the downpack/backfill technique. After insertion of a pressure sensor within the pulp chamber ten teeth of each group then underwent simulated dives with pressure measurement and the other ten a dye penetration test during simulated dives to 5.0 bar. Differences were analyzed statistically (P < 0.05) using one-way analysis of variance (ANOVA). Results. When the warm carrier-based gutta-percha obturation technique and vertical gutta-percha obturation techniques were used, there was significant lower intrapulpal pressure to experimental chamber pressure (P > 0.05). When cold lateral condensation or carrier-based Resilon as used, pressure was sometimes almost completely equalized. Conclusions. Warm gutta-percha obturation techniques provide a largely pressure-tight seal whereas the Resilon obturation technique and cold lateral condensation appear to be unsuitable to pressure changes.
Hydroxyapatite formation on a novel dental cement in human saliva.
Engstrand J, Unosson E, Engqvist H
ISRN Dent · 2012 · PMID 23056955 · Full text
Dental materials have to meet high standards regarding mechanical strength and handling properties. There is however only a limited amount of research that has been devoted to natural formation of hydroxyapatite (HA) in...
Dental materials have to meet high standards regarding mechanical strength and handling properties. There is however only a limited amount of research that has been devoted to natural formation of hydroxyapatite (HA) in contact with the materials. The objective of the current investigation was to study the surface reactions occurring in human salvia on a novel dental cement. Ceramir Crown & Bridge, a bioceramic luting agent intended for permanent cementation of conventional oral prosthetics, was evaluated by immersing discs made from the cement in human saliva and phosphate buffered saline (PBS) for seven days, after which they were dried and analyzed. The analytical methods used in order to verify HA formation on the surface were grazing incidence X-ray diffraction (GI-XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). All results showed that HA was formed on the surfaces of samples stored in saliva as well as on samples stored in PBS. The possibility of a dental luting cement to promote natural formation of HA at the tooth interface increases the stability and durability of the system and could help prevent secondary caries.
Integration of digital dental casts in cone-beam computed tomography scans.
Rangel FA, Maal TJ, Bergé SJ … +1 more , Kuijpers-Jagtman AM
ISRN Dent · 2012 · PMID 23050159 · Full text
Cone-beam computed tomography (CBCT) is widely used in maxillofacial surgery. The CBCT image of the dental arches, however, is of insufficient quality to use in digital planning of orthognathic surgery. Several authors h...
Cone-beam computed tomography (CBCT) is widely used in maxillofacial surgery. The CBCT image of the dental arches, however, is of insufficient quality to use in digital planning of orthognathic surgery. Several authors have described methods to integrate digital dental casts into CBCT scans, but all reported methods have drawbacks. The aim of this feasibility study is to present a new simplified method to integrate digital dental casts into CBCT scans. In a patient scheduled for orthognathic surgery, titanium markers were glued to the gingiva. Next, a CBCT scan and dental impressions were made. During the impression-taking procedure, the titanium markers were transferred to the impression. The impressions were scanned, and all CBCT datasets were exported in DICOM format. The two datasets were matched, and the dentition derived from the scanned impressions was transferred to the CBCT of the patient. After matching the two datasets, the average distance between the corresponding markers was 0.1 mm. This novel method allows for the integration of digital dental casts into CBCT scans, overcoming problems such as unwanted extra radiation exposure, distortion of soft tissues due to the use of bite jigs, and time-consuming digital data handling.
Lymphotoxin-Alpha Gene Polymorphism +252A/G (rs909253, A/G) Is Associated with Susceptibility to Chronic Periodontitis: A Pilot Study.
Vasconcelos DF, da Silva MA, Marques MR … +3 more , de Brito Júnior RB, Vasconcelos AC, Barros SP
ISRN Dent · 2012 · PMID 23050158 · Full text
Background. Periodontal disease leading to clinical findings such as increased periodontal probing depth involves a complex interaction between invading pathogenic microorganisms and the patient's immune system. Lymphoto...
Background. Periodontal disease leading to clinical findings such as increased periodontal probing depth involves a complex interaction between invading pathogenic microorganisms and the patient's immune system. Lymphotoxin alpha (LT-α) is a potent multifunctional immune modulator that contributes toward susceptibility to immune regulation disorders, including periodontal disease. Objective. In this study, we tested the hypothesis that chronic periodontitis (CP) is associated with polymorphisms of the LT-α gene. Materials and Methods. A total of 126 subjects, 44 healthy subjects, and 82 subjects with CP, were evaluated for periodontal disease by measuring clinical attachment loss and separation. Samples of epithelial cells were obtained for DNA analysis by scraping of the buccal mucosa. The LT-α gene was analyzed by polymerase chain reaction followed by endonuclease digestion with NcoI to analyze restriction fragment length polymorphisms. Results. The LT-α gene (+252A/G) polymorphism was associated with CP. LT-α allele frequencies were significantly different (P = 0.0019) between patients with CP and healthy individuals, with an odds ratio of 2.67 for patients with CP with the G allele. Conclusions. These findings suggest the LT-α gene genotype is a risk indicator for susceptibility to chronic periodontal disease in the Brazilian population studied.
Common Perceptions of Periodontal Health and Illness among Adults: A Qualitative Study.
Gholami M, Pakdaman A, Virtanen JI
ISRN Dent · 2012 · PMID 23029620 · Full text
Objective. Our aim was to explore perceptions of periodontal health and illness and to examine attitudes and beliefs regarding prevention of gum diseases among Iranian adults. Methods. Our qualitative approach included f...
Objective. Our aim was to explore perceptions of periodontal health and illness and to examine attitudes and beliefs regarding prevention of gum diseases among Iranian adults. Methods. Our qualitative approach included focus-group discussions among adults aged 18 and above based on convenient and purposive sampling in Tehran. Transcripts of the four focus-group discussions were analyzed by two independent reviewers using a content analysis method. Results. Two major themes in the analyses emerged: the common perception of periodontal health and illness and the attitude towards prevention. The study demonstrated the subjects' good understanding of prevention of periodontal disease, but their lack of knowledge of the aetiology of the diseases, and an inability to differentiate aetiology, symptoms, and prevention of dental caries and periodontal disease. Conclusion. This study revealed a need for oral health education among Iranian adults to improve their knowledge and change their attitudes to achieve deeper understanding of the aetiology and prevention of periodontal disease. Health promotion programs should address misconceptions about prevention of gum disease.
Radiopacity evaluation of contemporary luting cements by digitization of images.
Reis JM, Jorge EG, Ribeiro JG … +3 more , Pinelli LA, Abi-Rached Fde O, Tanomaru-Filho M
ISRN Dent · 2012 · PMID 23008777 · Full text
Objective. The aim of this study was to evaluate the radiopacity of two conventional cements (Zinc Cement and Ketac Cem Easymix), one resin-modified glass ionomer cement (RelyX Luting 2) and six resin cements (Multilink,...
Objective. The aim of this study was to evaluate the radiopacity of two conventional cements (Zinc Cement and Ketac Cem Easymix), one resin-modified glass ionomer cement (RelyX Luting 2) and six resin cements (Multilink, Bistite II DC, RelyX ARC, Fill Magic Dual Cement, Enforce and Panavia F) by digitization of images. Methods. Five disc-shaped specimens (10 × 1.0 mm) were made for each material, according to ISO 4049. After setting of the cements, radiographs were made using occlusal films and a graduated aluminum stepwedge varying from 1.0 to 16 mm in thickness. The radiographs were digitized, and the radiopacity of the cements was compared with the aluminum stepwedge using the software VIXWIN-2000. Data (mmAl) were submitted to one-way ANOVA and Tukey's test (α = 0.05). Results. The Zinc Cement was the most radiopaque material tested (P < 0.05). The resin cements presented higher radiopacity (P < 0.05) than the conventional (Ketac Cem Easymix) or resin-modified glass ionomer (RelyX Luting 2) cements, except for the Fill Magic Dual Cement and Enforce. The Multilink presented the highest radiopacity (P < 0.05) among the resin cements. Conclusion. The glass ionomer-based cements (Ketac Cem Easymix and RelyX Luting 2) and the resin cements (Fill Magic Dual Cement and Enforce) showed lower radiopacity values than the minimum recommended by the ISO standard.
Evaluation of manual and two-rotary niti retreatment systems in removing gutta-percha obturated with two root canal sealers.
Jayasenthil A, Sathish ES, Prakash P
ISRN Dent · 2012 · PMID 22997586 · Full text
Objective. The objective of this study was to evaluate the efficacy of two retreatment NiTi systems (protaper universal retreatment files, R-Endo), when compared to manual technique in removing Gutta-percha obturated wit...
Objective. The objective of this study was to evaluate the efficacy of two retreatment NiTi systems (protaper universal retreatment files, R-Endo), when compared to manual technique in removing Gutta-percha obturated with two sealers. Study Design. Sixty extracted single-rooted premolars were instrumented with Protaper rotary files till F3. The specimens were divided into six groups. Groups 1, 2, 3 were obturated with Gutta-percha and zinc oxide eugenol and Groups 4, 5, 6 were obturated with Gutta-percha and AH-plus. The retreatment was carried out in groups 1 and 4 with H-files and GGdrills, groups 2 and 5 with R-endo retreatment files and groups 3 and 6 with Protaper retreatment files. The roots were sectioned and evaluated under optical stereomicroscope. Statistical analysis was performed with one-way ANOVA and Newman-Keul's test at P < 0.05. Results. The manual technique resulted in cleaner canal walls when compared with both rotary retreatment systems. Conclusion. NiTi rotary retreatment files can be used to remove the filling material quickly, but it should be followed by hand instruments to obtain better canal wall cleanliness.
The Antibacterial Efficacy of Biopure MTAD in Root Canal Contaminated with Enterococcus faecalis.
Kamberi B, Bajrami D, Stavileci M … +3 more , Omeragiq S, Dragidella F, Koçani F
ISRN Dent · 2012 · PMID 22991671 · Full text
Aim. The purpose of this in vitro study was to assess the antimicrobial efficacy of Biopure MTAD against E. faecalis in contaminated root canals. Materials and Methods. Forty-two single rooted extracted human teeth were...
Aim. The purpose of this in vitro study was to assess the antimicrobial efficacy of Biopure MTAD against E. faecalis in contaminated root canals. Materials and Methods. Forty-two single rooted extracted human teeth were inoculated with E. faecalis and incubated for four weeks. The samples were divided in two control and five experimental groups irrigated with 1.5% sodium hypochlorite solution (NaOCl); 3% NaOCl; BioPure MTAD; 1.5% NaOCl/17% EDTA; or 3% NaOCl/17% EDTA. After a one-week incubation, complete disinfection was confirmed by the absence of turbidity in the incubation media. Dentin shavings were taken from samples with no turbidity to verify whether E. faecalis was present in dentin tubules. Results were analyzed statistically using Fisher's exact test, with the level of significance set at P < 0.05. Results. Statistical analysis of the data obtained at Day 7 and after dentin shaving analysis showed that BioPure MTAD had significantly greater antibacterial activity than 1.5% NaOCl, 1.5% NaOCl/17% EDTA and 3% NaOCl/17% EDTA. No significant difference was detected between MTAD and 3% NaOCl. Conclusions. These findings suggest that BioPure MTAD possesses superior bactericidal activity compared with NaOCl and EDTA against E. faecalis.
Compressive Strength and Setting Time of MTA and Portland Cement Associated with Different Radiopacifying Agents.
Tanomaru-Filho M, Morales V, da Silva GF … +4 more , Bosso R, Reis JM, Duarte MA, Guerreiro-Tanomaru JM
ISRN Dent · 2012 · PMID 22957262 · Full text
Objective. The aim of this study was to evaluate the compressive strength and setting time of MTA and Portland cement (PC) associated with bismuth oxide (BO), zirconium oxide (ZO), calcium tungstate (CT), and strontium c...
Objective. The aim of this study was to evaluate the compressive strength and setting time of MTA and Portland cement (PC) associated with bismuth oxide (BO), zirconium oxide (ZO), calcium tungstate (CT), and strontium carbonate (SC). Methods. For the compressive strength test, specimens were evaluated in an EMIC DL 2000 apparatus at 0.5 mm/min speed. For evaluation of setting time, each material was analyzed using Gilmore-type needles. The statistical analysis was performed with ANOVA and the Tukey tests, at 5% significance. Results. After 24 hours, the highest values were found for PC and PC + ZO. At 21 days, PC + BO showed the lowest compressive strength among all the groups. The initial setting time was greater for PC. The final setting time was greater for PC and PC + CT, and MTA had the lowest among the evaluated materials (P < 0.05). Conclusion. The results showed that all radiopacifying agents tested may potentially be used in association with PC to replace BO.
Computed Tomography Evaluation of Craniomandibular Articulation in Class II Division 1 Malocclusion and Class I Normal Occlusion Subjects in North Indian Population.
Prabhat KC, Kumar Verma S, Maheshwari S … +2 more , Ahmad I, Tariq M
ISRN Dent · 2012 · PMID 22957261 · Full text
Objective. The purpose of this study is to investigate the Craniomandibular articulation morphology and position of condyle in mandibular fossae in Angle's class I normal occlusion and Angle's class II division 1 maloccl...
Objective. The purpose of this study is to investigate the Craniomandibular articulation morphology and position of condyle in mandibular fossae in Angle's class I normal occlusion and Angle's class II division 1 malocclusion. Materials and Methods. The present study was conducted on 40 subjects with 20 subjects in each group, and the computed tomography images were obtained using spiral computed tomography technique. Each measurement was compared by two-factor analysis of variance (ANOVA) while changes in anterior and posterior joint spaces were done by paired t-test. Results. Statistically significant anterior positioning of condyle (P > 0.05) was observed in class I normal malocclusion, and it was significant only on right side in class II division 1 malocclusion. Conclusions. There was no difference found in the condylar process and joint morphology between right and left sides of both Angle's Class I normal occlusion and Angle's class II division 1 malocclusion. Evaluation of the position of the condyles in their respective mandibular fossae showed concentric position with a tendency towards anterior positioning for both right and left sides of the subjects with Angle's Class I normal occlusion as well as subjects with Angle's class II division 1 malocclusion.
Orthodontic tooth movement with clear aligners.
Drake CT, McGorray SP, Dolce C … +2 more , Nair M, Wheeler TT
ISRN Dent · 2012 · PMID 22928114 · Full text
Clear aligners provide a convenient model to measure orthodontic tooth movement (OTM). We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement. Fifteen subjects seeking ort...
Clear aligners provide a convenient model to measure orthodontic tooth movement (OTM). We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement. Fifteen subjects seeking orthodontic treatment at the University of Florida were enrolled. Results were compared with data previously collected from 37 subjects enrolled in a similar protocol. Subjects were followed prospectively for eight weeks. An upper central incisor was programmed to move 0.5 mm. every two weeks using clear aligners. A duplicate aligner was provided for the second week of each cycle. Weekly polyvinyl siloxane (PVS) impressions were taken, and digital models were fabricated to measure OTM. Initial and final cone beam computed tomography (CBCT) images were obtained to characterize OTM. Results were compared to data from a similar protocol, where subjects received a new aligner biweekly. No significant difference was found in the amount of OTM between the two groups, with mean total OTM of 1.11 mm. (standard deviation (SD) 0.30) and 1.07 mm. (SD 0.33) for the weekly aligner and biweekly control groups, respectively (P = 0.72). Over eight weeks, in two-week intervals, material fatigue does not play a significant role in the rate or amount of tooth movement.
A primer on network meta-analysis for dental research.
Tu YK, Faggion CM
ISRN Dent · 2012 · PMID 22919506 · Full text
In the last decade, a new statistical methodology, namely, network meta-analysis, has been developed to address limitations in traditional pairwise meta-analysis. Network meta-analysis incorporates all available evidence...
In the last decade, a new statistical methodology, namely, network meta-analysis, has been developed to address limitations in traditional pairwise meta-analysis. Network meta-analysis incorporates all available evidence into a general statistical framework for comparisons of all available treatments. A further development in the network meta-analysis is to use a Bayesian statistical approach, which provides a more flexible modelling framework to take into account heterogeneity in the evidence and complexity in the data structure. The aim of this paper is therefore to provide a nontechnical introduction to network meta-analysis for dental research community and raise the awareness of it. An example was used to demonstrate how to conduct a network meta-analysis and the differences between it and traditional meta-analysis. The statistical theory behind network meta-analysis is nevertheless complex, so we strongly encourage close collaboration between dental researchers and experienced statisticians when planning and conducting a network meta-analysis. The use of more sophisticated statistical approaches such as network meta-analysis will improve the efficiency in comparing the effectiveness between multiple treatments across a set of trials.
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