Search results for " Biomedical"
showing 10 items of 480 documents
Effect of different mixing and placement methods on the quality of MTA apical plug in simulated apexification model
2017
Background It is necessary apical plug material to exhibit proper adaptation with the root canal walls. Presence of voids at the interface between the root canal wall and this material result in micro leakage, which might have a relationship with post treatment disease. The aim of the present study was to evaluate the effect of different mixing (manual and ultrasonic) and placement (manual and manual in association with indirect ultrasonic) method of Mineral Trioxide Aggregate (MTA) on the void count and dimension in the apical plug in natural teeth with simulated open apices. Material and methods Eighty human maxillary central incisors were selected. After simulation of the open apex model…
The Discoloration effect of White Mineral Trioxide Aggregate (WMTA), Calcium Enriched Mixture (CEM), and Portland Cement (PC) on Human Teeth
2017
Background The aim of this study was to evaluate the discoloration induced by CEM cement, Portland cement (PC) and MTA mixed with propylene glycol (MTA-PG) in comparison to White MTA. Material and methods Ninety extracted premolar and canine teeth were resected 2 mm below the CEJ. The coronal part of crown was prepared with peeso reamer and Gates-Glidden drills, and the specimens were randomly divided into 4 experimental (n=20) and one control (n=10) groups. The tooth crowns in experimental groups 1 to 4 were filled with White MTA, PC, CEM cement and MTA-PG, respectively; and in group 5, the teeth were kept empty. After incubation, digital photographs of teeth were acquired at 4 time points…
A nonlinear mixed model approach to predict energy expenditure from heart rate.
2021
Abstract Objective. Heart rate (HR) monitoring provides a convenient and inexpensive way to predict energy expenditure (EE) during physical activity. However, there is a lot of variation among individuals in the EE-HR relationship, which should be taken into account in predictions. The objective is to develop a model that allows the prediction of EE based on HR as accurately as possible and allows an improvement of the prediction using calibration measurements from the target individual. Approach. We propose a nonlinear (logistic) mixed model for EE and HR measurements and an approach to calibrate the model for a new person who does not belong to the dataset used to estimate the model. The …
Efficacy of electrical neuromuscular stimulation in the treatment of chronic periodontitis
2011
Purpose: The purpose of the present randomized controlled clinical study was to evaluate the short-term outcomes of microcurrent electrical neuromuscular stimulation (MENS) as an adjunct method to nonsurgical periodontal therapy. Methods: Twenty patients with moderate to severe chronic periodontitis were recruited into the study and randomly treated with either nonsurgical periodontal therapy followed by 5 MENS treatments with a microcurrent device or by nonsurgical periodontal therapy alone. Periodontal parameters were measured at baseline and 6 weeks following therapy, and included the plaque index, bleeding on probing, probing depth, and clinical attachment level (CAL). Results: All meas…
Peri-implant defect grafting with autogenous bone or bone graft material in immediate implant placement in molar extraction sites-1- to 3-year result…
2020
Objectives To evaluate the survival rate, the orobuccal bone resorption and stability of peri-implant hard and soft tissues following immediate implant placement of wide diameter implants in molar extraction sites and peri-implant defect grafting with autogenous bone (AB) or biphasic bone graft material (BBGM) with 1- to 3-year follow-up examinations. Material and methods Fifty wide diameter implants were placed in 50 patients immediately into molar extraction sockets by a flapless approach. Peri-implant defect augmentation was performed randomized with either AB or BBGM. Primary outcome variable was implant survival. Marginal bone level changes, orobuccal width of the alveolar crest, probi…
Periodontal health in shortened dental arches: A 10-year RCT
2020
Journal of prosthodontic research 64(4), 498-505 (2020). doi:10.1016/j.jpor.2020.01.005
Effect of Chlorhexidine on durability of two self-etch adhesive systems
2020
Background Despite of the rapid development in the field of dental adhesives, the issue of reduction in dentin bond durability has still not been resolved. The activity of dentinal endogenous enzymes such as MMPs is one of the most important causes of failure in resin composite restorations. The aim of this study was to investigate the influence of Chlorhexidine on micro-tensile bond strength of two types of commercially available self-etch adhesives. Material and Methods Twenty four sound and freshly extracted molars were selected. Four standardized flat mid-coronal dentinal disks were prepared from each tooth. The specimens were randomly assigned to 6 groups (n=16). Groups A(control group…
Influence of Hyrax screw position on dental movement and cortical bone : a study of finite elements
2019
Background Rapid maxillary expansion (RME) has effects on the dental and periodontal structures of the parts involved, which vary according to the design and position of the expansion screw. The purpose of the study was to determine the optimal three-dimensional position of the Hyrax screw to obtain precise control of the dental movement and effect on the bone cortex using the finite element method (FEM). Material and methods RME was performed from the patient whom two Cone-Beam computerized tomography scans (CBCT) were obtained: T1 before expansion, and T2 three months after stabilization of RME. The FEM model was designed with T1 and of Hyrax photographs. FEM was obtained by comparing the…
Does hybridized dentin affect bond strength of self-adhesive resin cement?
2016
Background: Evaluate the influence of different hybridization bonding techniques of a self-adhesive resin cement. Material and Methods: 30 human health molars were divided into six groups (n=10). The specimens received three longitudinal sections, allowing insertion of central cuts in PVC matrices. Each group received a different dentin pretreatment according to the manufacturerâ s recommendations, except the control group (G1), as follows. G2 - a 3-step total-etch adhesive system (Optibondâ ¢ FL, Kerr); G3 - a 3-step total-etch adhesive system (Adperâ ¢ Scotchbondâ ¢ Multi-Purpose, 3M ESPE); G4 - a 2-step total-etch adhesive system (Adperâ ¢ Single Bond 2, 3M ESPE); G5 - a single-step self…
<i>In vitro</i> evaluation of microleakage in Class II composite restorations: High-viscosity bulk-fill <i>vs</i> conventiona…
2019
This study compared marginal microleakage of Class II cavities restored with bulk-fill resin (Filtek™ Bulk Fill) and conventional composite resin (Filtek™ Supreme XTE). Two standardized Class II cavities were prepared in forty extracted human molars. The gingival margin was located above the cemento-enamel junction for twenty molars (groups 1 and 2) and apically for the other twenty (groups 3 and 4) (n=20). The occlusomesial cavity was filled with bulk-fill resin by insertion in bulk (groups 1 and 3) and the occlusodistal cavity was restored with conventional composite using incremental technique (groups 2 and 4). The teeth were thermocycled (500 cycles 5-55°C), stained and observed under l…