Lyngeharbo7728
To compare fracture resistance between the cement-retained (CR), screw-retained (SR), and combined cement- and screw-retained (CCSR) metal-ceramic (MC) implant-supported molar restorations and the fracture mode after vertical loading simulation.
Thirty MC molar restorations were fabricated on thirty tilted dental implants that were repositioned using prefabricated or universal castable long abutments (UCLA) with 15° of angulation divided into three groups of ten specimens each. Group C CR, group S SR, and group CS cement- and screw-retained. The crowns in group CS were adhesively bonded extraorally, and composite resin was used to fill the screw access holes (SAHs) in groups S and CS. Subsequently, all the specimens were tested for fracture resistance. A scanning electron microscope (SEM) evaluation of the fracture mode was also performed. Mean values of fracture loads were calculated and compared in Newtons (N) using one-way ANOVA and Tukey
test (
< 0.05) for each group.
Mean fracture load valuer alternative for dental implant rehabilitation.
Combined cement- and screw-retained restorations (CCSRRs) incorporate the simplicity of the cement method and the retrievability of the screw method, offering good resistance, allowing the removal of the excess of cement before clinical placement of the restoration, and providing another alternative for dental implant rehabilitation.
The present study aimed to evaluate the effect of various root-conditioning agents on root surfaces that are periodontally affected.
A total of 90 human teeth having single root that were extracted because of chronic periodontitis were chosen. The extracted teeth were cleaned of saliva and blood using a soft-bristled brush and distilled water. The investigational groups were categorized into group I-doxycycline HCl, group II-ethylenediaminetetraacetic acid, and group III-tetracycline HCl. Samples were readied for histological study by scanning electron microscope (SEM). The SEM was used to assess the effectiveness of smear layer removal, amount of patent dentinal tubules out of the totality of dentinal tubules present, and the appreciation of collagen fiber-like structures inside the intertubular area.
The highest efficacy for smear layer removal was seen for group III-tetracycline HCl samples (1.80 ± 0.148) followed next by group II-EDTA (1.36 ± 0.230), and group I-doxycycline HCl (1.30 ± 0.283). The hodontal treatment goals.
This study aimed to assess the effect of addition of nano-titanium oxide (nano-TiO
), nano-silicon dioxide (nano-SiO
), and a combination of both, on antimicrobial activity of an orthodontic composite.
Molds measuring 0.64 × 0.5 mm were used for the fabrication of composite disks. For this purpose, 0.5% and 1% nano-TiO
, nano-SiO
, and a combination of both (0.5% nano-TiO
and 0.5% nano-SiO
), were mixed with Transbond XT composite (3M Unitek). A total of 180 composite disks were fabricated for eluted component, disk agar diffusion (DAD), and biofilm inhibition tests. The colony counts of
(
),
(
), and
(
) and the diameters of growth inhibition zones were measured at 3, 15, and 30 days after exposure to the materials. Data were analyzed using one-way ANOVA and a
test.
None of the nano-TiO
and nano-SiO
concentrations had any significant effect on the growth inhibition zone. All tested concentrations of nano-TiO
and nano-SiO
decreased the colony count of all bacteria. The composite sample containing both nano-TiO
and nano-SiO
had the greatest efficacy for reduction of
and
colony counts at all three time points. Also, 1% nano-TiO
and 1% nano-SiO
had similar effects on
in eluted component test.
Addition of TiO
and SiO
nanoparticles conferred antimicrobial property to the tested orthodontic composite.
Using orthodontic composite containing nonoparticles with antibacterial activity may prevent dental caries.
Using orthodontic composite containing nonoparticles with antibacterial activity may prevent dental caries.
To compare the vertical margin accuracy of lost wax castings produced by the conventional casting technique with all metal (WIRONIUM®) and PFM alloy (WIRON®99) using a metal ring and ringless system.
A brass die assembly was used to fabricate standardized wax pattern crowns. A total of 100 wax patterns were made with both ringless and metal ring investment systems. Wax patterns were readapted and refined on the master die and divided into two groups, namely, group I and group II with 50 wax patterns in each group. Group I (ringless system) and group II (metal ring system) were further divided into subgroups having a sample size of 25 in each group. Each coping was invested and cast individually. The marginal discrepancy between the metal die and the castings were measured by a stereomicroscope and AutoCAD software 2013. Measurement was made on the facial area of the metal die.
The resultant casts obtained from different casting systems show statistically significant difference found between the marginal and use of occlusal vents or die spacers.
To compare the effect of visual information and verbal communication on the level of anxiety among patients undergoing dental implant (DI) therapy.
A total of 270 patients who were undergoing DI treatment were recruited for the study. An equal number of patients (
= 90) were randomly allocated into three study groups which were formed on the basis of the mode of delivery. Subjects in group I received verbal information, whereas patients in group II were shown a video of surgery on manikins. Group III subjects were made to watch a video of surgery on a real patient. Before the surgery, anxiety levels were measured for all patients using the modified Corah dental anxiety scale (MDAS).
Questionnaires were filled by all patients and were later analyzed. The values of Cronbach's α and the behavioral involvement subscale were 0.89 and 0.91, indicating hemogeneous sample. Patients of group I showed significantly reduced anxiety levels (
< 0.01) followed by groups II and III.
Verbal information generated less anxiety than visual information on patients undergoing DI therapy.
To assess the best method of information delivery to dental implant patients in which their anxiety will be minimal.
To assess the best method of information delivery to dental implant patients in which their anxiety will be minimal.
The aim of this study is to compare the canal cleaning ability of S-One file (AF BLUE) system with WaveOne Gold single file system, using scanning electron microscopy (SEM).
In the present study, 40 freshly extracted permanent mandibular premolars with a single-root canal and straight roots were selected. The teeth were randomly divided into three groups. The canals were prepared by crown-down technique. Telratolimod chemical structure Buccolingual sectioning of the samples were done followed by SEM evaluation. Data were statistically analyzed using Kruskal-Wallis test. The statistical significance level was set at
value <0.05.
The analysis of the results demonstrated that WaveOne presented higher cleaning capacity of root canals with a statistically significant difference, when compared to S-One file system (
value < 0.05). Both the file systems showed significant cleaning efficacy in the coronal and middle-thirds of the root canals when compared to the apical thirds. Also, the WaveOne showed better results than S-One (AF BLUE), and the results were statistically significant.
With the limitation of the study, the cleaning ability of rotary file system is high in coronal and middle-third followed by apical third. In this study, the WaveOne showed better results than S-One (AF BLUE), and the results were statistically significant.
The aggressive cutting of dentin during canal preparation is less in WaveOne file than S-One file system. The cleaning efficiency is good in reciprocating file system (WaveOne) than continuous rotary file system (S-One).
The aggressive cutting of dentin during canal preparation is less in WaveOne file than S-One file system. The cleaning efficiency is good in reciprocating file system (WaveOne) than continuous rotary file system (S-One).
To investigate by the finite element analysis comparison of stress distribution on the cortical and cancellous bone in an implant-supported yttrium tetragonal zirconia polycrystals (Y-TZP FPD) in four different widely used implant systems under different loading conditions.
Four 3-D finite element analysis (FEA) models of mandible having different implant systems with dimensions 8.0 mm × 5 mm in the second premolar and molar region were developed. In these models, abutment was tightened and 3-unit implant-supported Y-TZP FPD were cemented. A lateral force component of 100 N at 30° to the occlusal plane and a vertical intrusive force component of 250 N were applied to the central fossa of the FDP and the stress on bone around the implant was analyzed by FEA.
In the four implant systems, the maximum stress values on the crestal bone differ for the different implant systems for the two loading conditions applied. In both cases, the maximum stress values on the cortical bone were in ADIN Touareg Closefit WPhe least load was transferred by the Nobel Active implants due to the reverse buttress thread design and larger thread pitch.
To compare the vertical marginal discrepancy of retrievable cement/screw-retained design (RCSRD) and cement-retained (CR) implant-supported single metal copings cemented on implant abutments.
Single metal copings were fabricated for 20 4.5 × 10 mm titanium dental implants. Two groups of 10 implants each were randomly allocated. One group received RCSRD metal copings and the other group received CR metal copings. Both types of restorations were fabricated on solid abutments with 5.5 mm of diameter. The copings were cemented with resin cement. After the cementation procedure, cement excess was carefully removed in both groups. Inspections of coping-abutment vertical marginal discrepancy were measured using scanning electronic microscopy (SEM) under 800× magnification. The independent sample Student's
test was used to detect differences between groups (
< 0.05).
The RCSRD implant-supported metal coping group (57.80 ± 2.34 μm) showed statistically better vertical marginal discrepancy than the CR implant-supported metal coping group (64.40 ± 2.23 μm) (
= 0.001).
The RCSRD implant-supported metal copings offer less vertical marginal discrepancy than the CR copings group. This new technique would decrease the marginal discrepancy with less bacterial filtration and biomechanical problems.
Retrievable cement/screw-retained design is another alternative technique for dental implant rehabilitation that combines the advantages of CR and SR prostheses. The hybrid design offers less vertical marginal discrepancy for better control of bacterial filtration and biomechanical problems.
Retrievable cement/screw-retained design is another alternative technique for dental implant rehabilitation that combines the advantages of CR and SR prostheses. The hybrid design offers less vertical marginal discrepancy for better control of bacterial filtration and biomechanical problems.
