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Information on the dimensional changes in maxillary and mandibular dentures made by using computer-aided design and computer-aided manufacturing (CAD-CAM) techniques under uniform testing conditions is lacking.The purpose of this in vitro study was to evaluate the dimensional changes and reproducibility of maxillary and mandibular dentures by using CAD-CAM-milled and 3D-printed techniques.Maxillary and mandibular edentulous models with wax occlusal rims were scanned, and dentures were designed by using a CAD software program and fabricated by using 2 techniques and materials: CAD-CAM-milled (CCM) and 3D-printed (3DP). The 3DP fabrications included 4 subgroups: dentures printed with a 90-degree build angle with UV light polymerization on the reference model (3DP 90M), dentures printed with a 90-degree build angle and light polymerization without the reference model (3DP 90), dentures printed with a 45-degree build angle with light polymerization on the reference model (3DP 45M), and dentures printed with a 45-degree build angle and light polymerization without the reference model (3DP 45). The preprocessing and postprocessing scan files of each denture produced by CCM and 3DP were superimposed by using a surface matching software program. Ten points each on maxillary and mandibular dentures were measured for deviations after processing. Additionally, for each denture, the widths were measured between the canines and molars, the anteroposterior plane from cusp tips between the canines and molars, and the vertical plane from the cusp tip of the canines to the marginal gingiva. They were then compared with those in the denture design CAD cast. The Kruskal-Wallis analysis of variance test was used for statistical analyses (α=.05).According to digital superimposition, CCM had the smallest values of deviation with no statistical difference (P.05), indicating more uniform results from measurement points in both maxillary and mandibular dentures, followed by 3DP 90M, 3DP 90, 3DP 45M, and 3DP 45. Regarding the width measurements, CCM had the smallest values of deviation (P.05). In 3DP, smaller deviation values were observed at the vertical plane from the tip of the canine to the marginal gingiva, and larger values were observed in the intermolar width (P.05).CCM exhibited smaller dimensional changes and better reproducibility among the tested techniques. In 3DP, the build angle and methods of light postprocessing influenced the dimensional stability. The 90-degree build angle with additional light polymerization on the cast improved the dimensional deviations.

Vat-polymerized casts can be designed with different bases, but the influence of the base design on the accuracy of the casts remains unclear.The purpose of the present in vitro study was to evaluate the influence of various base designs (solid, honeycombed, and hollow) with 2 different wall thicknesses (1 mm and 2 mm) on the accuracy of vat-polymerized diagnostic casts.A virtual maxillary cast was obtained and used to create 3 different base designs: solid (S group), honeycombed (HC group), and hollow (H group). The HC and H groups were further divided into 2 subgroups based on the wall thickness of the cast designed: 1 mm (HC-1 and H-1) and 2 mm (HC-2 and H-2) (N=50, n=10). All the specimens were manufactured with a vat-polymerized printer (Nexdent 5100) and a resin material (Nexdent Model Ortho). The linear and 3D discrepancies between the virtual cast and each specimen were measured with a coordinate measuring machine. Trueness was defined as the mean of the average absolute dimensional discrepancy between the virtual cast and the AM specimens and precision as the standard deviation of the dimensional discrepancies between the virtual cast and the AM specimens. The Kolmogorov-Smirnov and Shapiro-Wilk tests revealed that the data were not normally distributed. The data were analyzed with Kruskal-Wallis and Mann-Whitney U pairwise comparison tests (α=.05).The trueness ranged from 63.73 μm to 77.17 μm, and the precision ranged from 44.00 μm to 54.24 μm. The Kruskal-Wallis test revealed significant differences on the x- (P.001), y- (P=.006), and z-axes (P.001) and on the 3D discrepancy (P.001). On the x-axis, the Mann-Whitney test revealed significant differences between the S and H-1 groups (P.001), S and H-2 groups (P.001), HC-1 and H-1 groups (P.001), HC-1 and H-2 groups (P.001), HC-2 and H-1 groups (P.001), and HC-2 and H-2 groups (P.001); on the y-axis, between the S and H-1 groups (P.001), HC-1 and H-1 groups (P=.001), HC-1 and H-2 groups (P=.02), HC-2 and H-1 groups (P.001), HC-2 and H-2 groups (P=.003); and on the z-axis, between the S and H-1 groups (P=.003). For the 3D discrepancy analysis, significant differences were found between the S and H-1 groups (P.001), S and H-2 groups (P=.004), HC-1 and H-1 groups (P=.04), and HC-2 and H-1 groups (P=.002).The base designs tested influenced the manufacturing accuracy of the diagnostic casts fabricated with a vat-polymerization printer, with the solid and honeycombed bases providing the greatest accuracy. However, all the specimens were clinically acceptable.

Stresses induced by implant-supported prostheses are related to mechanical complications. However, how the manufacturing method affects the generated stresses is unclear.The purpose of this in vitro study was to compare the passive fit of 3-unit cobalt-chromium partial prostheses fabricated by using 3 different methods: conventional casting (milled resin with lost-wax method), machined (milling soft metal blocks), or sintered (direct metal laser sintering).Thirty 3-unit implant-supported cobalt-chromium fixed prostheses were fabricated, 10 with each method. Four strain gauges were placed over an in vitro resin model with 2 implants in it; 2 gauges were placed above and 2 on the sides to measure the microdeformations caused by placing the structures above the implants in longitudinal flexion, vertical flexion, or torsion, before and after tightening the screws. An inferential analysis was carried out by using a statistical software program, and the Wilcoxon and Kruskal-Wallis tests were applied and then complemented with the Mann-Whitney test for multiple comparisons with the Bonferroni correction (α=.01).The mean longitudinal deformation, vertical flexion, and torsional deformation values increased after tightening the screws with each of the 3 fabrication methods. Significant differences (P.01) were found for all 3 methods before and after screw tightening. After screw tightening, the machined structures, followed by sintered structures, and the cast structures (P.05) had smaller deformations in the X, Y, and Z dimensions. The longitudinal deformation was less in machined structures, and vertical flexion deformation was less in machined and sintered structures than in cast structures (P.05).The deformations registered in the in vitro model increase considerably after screw tightening, which indicates the lack of passive fit. Machined structures provide a better passive fit, followed by sintered structures, and the cast structures had the poorest fit.

Statement of problem Studies evaluating the accuracy of edentulous arch impressions encompassing conventional and digital methods are lacking. Purpose The purpose of this in vitro study was to evaluate 8 impression-making methods for edentulous arches and to determine the effects of using a 3-dimensionally printed polyetheretherketone (PEEK) scanning aid on the accuracy of intraoral scanners. Material and methods Three sets of edentulous arch typodonts were scanned with an industrial scanner as a reference. Subsequently, a scanning aid for the edentulous arch was individually designed on each reference scan dataset by using a 3-dimensional modeling software program and fabricated in PEEK with a 3-dimensional printer. Each typodont was scanned with 2 intraoral scanners 12 times, with and without the assistance of a scanning aid for the edentulous arch. Impressions were made with 4 different conventional impression materials (irreversible hydrocolloid, polysulfide, polyether, and polyvinyl siloxane)—12 times for each typodont—the casts were poured and digitized with a tabletop scanner. Each scan data set was superimposed over the corresponding scan data set, and the original and absolute distance values from the paired surface points were obtained to measure the trueness and precision. These were expressed by using the mean, median, root mean square, and (90 percentile-10 percentile)/2 of the absolute distance value (NMT) concepts, based on the raw data extraction protocol. A repeated-measures ANOVA followed by a post hoc Bonferroni test was conducted (α=.05). Results The impression-making methods did not show statistically significant differences (P>.05) for either trueness or precision, particularly when the median values of the original and absolute distance values from the paired surface points were chosen as the standard values. One of the intraoral scanners used exhibited significantly superior outcomes to conventional impression materials when scanned with the scanning aid for the edentulous arch for both trueness and precision when the mean, root mean square, and NMT concepts were applied (P Conclusions Intraoral scanners demonstrated accuracy comparable with that of conventional impression materials for making edentulous arch impressions, regardless of the concepts used to express the trueness and precision. The PEEK-based scanning aid for the edentulous arch did not improve the accuracy of the intraoral scanners; however, its application resulted in higher accuracy compared with that of conventional impression materials.

Stereolithography (SLA) additive manufacturing (AM) technologies have become popular for the fabrication of complete dentures; however, the trueness and precision of the dentures under different postpolymerization conditions remain unclear.The purpose of this in vitro study was to investigate the effect of different postpolymerization times and temperatures on the trueness and precision of SLA dentures.Specimens simulating maxillary complete dentures were fabricated by SLA 3D printing. They were polymerized for 15 minutes or 30 minutes at different temperatures (40 °C, 60 °C, and 80 °C). The intaglio surface trueness of the specimens was evaluated by superimposing the postpolymerization standard tessellation language (STL) file on the original STL file for each specimen via a best-fit method (n=10). The precision was measured across specimens by superimposing the postpolymerization STL file from each specimen group and using the combination formula (n=45). Subsequently, root-mean-square estimates (RMSEs) and color map data were obtained, and a normality test was conducted on the obtained data. The results indicated that the distributions were not normal; therefore, nonparametric Kruskal-Wallis and Mann-Whitney tests were used to analyze the data (α=.05).For trueness, the lowest RMSE corresponded to the postpolymerization time of 30 minutes and a temperature of 40 °C. This result was significantly different from specimens those of the 15-minute and 60 °C, 15-minute and 80 °C, and 30-minute and 80 °C specimens (P.001). For precision, the median of the lowest RMSE corresponded to the 30-minute and 40 °C specimens. This median value was significantly different from those of other specimens (P.001). The findings indicate that the postpolymerization condition of 30 minutes and 40 °C affords the highest trueness and precision and the most favorable intaglio surface adaptation of the denture.The postpolymerization conditions influenced the RMSE values of the trueness and precision of a clear photopolymer resin. The RMSE and color map data associated with the 30-minute and 40 °C condition corresponded to the greatest trueness and precision of all the SLA denture specimens considered.

The digital scan accuracy of different intraoral scanners (IOSs) for long-span fixed prosthesis and the effect of the starting quadrant on accuracy is unclear.The purpose of this in vitro study was to evaluate the accuracy of 6 IOSs for complete-arch and prepared teeth digitally isolated from the complete-arch and to determine the effect of the starting quadrant on accuracy.A maxillary model containing bilaterally prepared canines, first molar teeth, and edentulous spans between the prepared teeth was used. The model was scanned by using a highly accurate industrial scanner to create a digital reference data set. Six IOSs were evaluated: TRIOS, iTero, Planmeca Emerald, Cerec Omnicam, Primescan, and Virtuo Vivo. The model was scanned 10 times with each IOS by 1 operator according to the protocols described by the manufacturers. Five scans were made starting from the right quadrant (ScanR), followed by 5 scans starting from the left quadrant (ScanL). All data sets were obtained in standard tessellation language (STL) file format and were used to evaluate accuracy (trueness and precision) with a 3D analyzing software program (Geomagic Studio 12; 3D Systems) by using a best-fit alignment. The prepared teeth were digitally isolated from the complete-arch and evaluated with the analyzing software program. The Kruskal-Wallis and Mann-Whitney U statistical tests were used to detect differences for trueness and precision (α=.05).Statistically significant differences were found regarding IOSs (P.003) and scanning sequence (P.05). The TRIOS showed the best trueness for the complete-arch, but not statistically different from Primescan, Virtuo Vivo, and iTero (P.003). The lowest median values for precision of the complete-arch were also found using TRIOS, but no significant difference was found among the scanners (P.003). In terms of trueness and precision, Primescan had the best accuracy for preparations. Emerald showed significant differences depending on the scanning sequence for complete-arch accuracy. ScanR for trueness (P=.021) and ScanL for precision (P=.004) showed improved results. However, Emerald, TRIOS, and Virtuo Vivo showed statistically significant differences in precision of preparations depending on scanning sequence. ScanL deviated less than ScanR when scanned with TRIOS (P=.025) and Emerald (P=.004), and the opposite with Virtuo Vivo (P=.008). In terms of preparations trueness, no significant difference was found between the ScanR and ScanL of any IOS (P.05).Based on this in vitro study, the accuracy of the complete-arch and prepared teeth differed according to the IOS and scanning sequence.

Statement of problem The use of reduced platform sets (implants and abutments) can help to control crestal bone loss around implants, which is essential for optimizing esthetics and biomechanical behavior. However, the information available on the fracture resistance of implants with a reduced platform is sparse. Purpose The purpose of this in vitro study was to analyze the maximum fracture strength value of implants with different platform designs during quasistatic fatigue, followed by a simulation of different bone levels of cervical insertion. Material and methods One hundred and twenty sets of dental implants and abutments with different diameters and platform designs were tested. All implants had an internal hexagon connection and conical macrogeometry. Four groups (n=30) were studied: O4.0-mm implants with a regular matched platform (rMatch group), O4.0-mm implants with a regular switched platform (PSwitch group), O5.0-mm implants with a wide matched platform (wMatch group), and O5.0-mm implants with a wide switched platform (wSwitch group). Three conditions simulating different levels of bone position around the cervical portion of the implants were proposed: insertion at the implant shoulder level=0 mm (L0), level=3 mm of insertion loss (L3), and level=5 mm of insertion loss (L5). All sets of all groups and proposed insertion level were subjected to a fracture strength test at 30 degrees in relation to the axis of the sets in a universal testing machine. Results Regardless of the insertion levels tested, the switched platform implants (rSwitch and wSwitch groups) showed similar mean fracture strength values (P>.05), while the implants of matched platforms (rMatch and wMatch groups) showed different fracture strength values for all insertion levels tested (P Conclusions The fracture strength values of the switched platform implants were lower at all insertion levels tested. However, for all insertion levels tested, the implants with a switched platform presented less deformation, whereas, in the matched platform implants, there was significant deformation of the implant structure.

Background/purpose Although several mechanical and chemical debridement techniques have been reported for the management of peri-implantitis, there is no consensus on the most effective method at present. This in vitro study aimed to examine the effects of different mechanical instrumentation techniques on the debridement of hard calcified materials, which are present on the implant surface, as well as the effect of the defect morphology. Materials and methods From a total of 15 implants, five each were assigned to one of three decontamination groups (Rotary titanium brush [Ti], tricalcium phosphate air powder abrasive treatment [Air], and titanium ultrasonic scaler [US] groups); the exposed hydroxyapatite (HA)-coated portion was divided into three 1-mm sections (coronal, middle, and apical). The residual-HA of each portion was measured using a digital microscope. Results The overall percentage of residual HA coating was significantly lower in the US group than in the Ti or Air groups (p Conclusion Ti and US were more effective for shallow defects, whereas US was more effective for deeper defects.

The trans-cell approach using a low-profile visualized intraluminal support (LVIS) device is sometimes used for aneurysm coil embolization. However, factors related to microcatheter passage remain uninvestigated. We aimed to examine in-vitro factors related to microcatheter passage using the trans-cell approach with an LVIS.Silicone vessel models (inner diameter, 4 mm) were created with different bend segments and a 4-mm hole assuming an aneurysm neck on the side of the greater curvature. The LVIS Blue (4.5 × 32 mm) was deployed at the bend segment, and passability on the trans-cell surface was evaluated by passing the microcatheter along the micro guidewire. A total of 800 passage experiments were performed using two types of microcatheter, ten types of silicone vessel, four cell widths, five cells with the same LVIS device, and two micro guidewire directions in the aneurysm.The Headway Duo microcatheter (35.5%, 142/400) tended to have better passability compared with the Headway 17 microcatheter (29.3%, 117/400) (p = 0.070). As the cell width and angle between the trans-cell surface and microcatheter direction increased, passability significantly increased (p = 0.027 and p 0.001, respectively). There was no significant difference in passability when the micro guidewire was directed to the proximal side versus the distal side (p = 0.45).A large cell width and an obtuse angle between the trans-cell surface and microcatheter direction facilitated good passability. Although statistically marginal, microcatheters with small ledges and small tips had relatively good passability.

Modern approach towards biodegradable biomaterials involves significant capability of magnesium (Mg) alloys. Being a major constituent of the human body, Mg has extraordinary potential to facilitate as temporary orthopaedic implants. Despite many benefits within Mg and its alloys; such as excellent biocompatibility, biodegradability, satisfactory mechanical qualities, its use is still very limited. Rapid corrosion and hydrogen evolution are threats to its limited use. To estimate the mechanism and causes of corrosion in living environments for Mg-alloys accurately, in vitro study is necessary. The present review focuses on factors influencing corrosion rates (bio-corrosion) of Mg-alloys in vivo and in vitro studies. To understand the corrosion behaviour, factors like organic compounds, inorganic ions and some experimental process parameters taken into considerations and are analyzed. It is concluded that some of these factors affect the mechanism of corrosion greatly and their effective management is required to control their corrosion rates. Experimental conditions are most significant because they affect corrosion rates the most and can be helpful to stabilize it. The effects of these factors are summarized at the end of this review.

Computer-aided design and computer-aided manufacturing (CAD-CAM) systems are increasingly used to fabricate removable complete dentures. However, comparisons and analyses of the trueness and adaptation of the socketed surface of denture bases produced by milling (MIL) and digital light processing (DLP) are lacking.The purpose of this in vitro study was to evaluate and compare the trueness and socketed surface adaptation of denture bases fabricated by using additive and subtractive manufacturing.Based on a denture base standard tessellation language (STL) file, a total of 15 denture bases were produced by using DLP (horizontal and vertical direction) and MIL. The intaglio and cameo surfaces of the fabricated denture bases were scanned with a dental scanner. The scanned intaglio and cameo surfaces were overlapped with the corresponding reference denture base STL file for trueness evaluation. In addition, the ridge lap STL file of the diagnostic tooth arrangement, in which reverse normal was performed, was superimposed on the socketed surface of the denture base of all groups to evaluate adaptation.The root mean square (RMS) values of trueness and adaptation showed statistically significant differences (P.05). For the trueness RMS value of the intaglio surface of the denture base, the MIL-denture base (MDB) group had the lowest value of 150 ±6 μm, whereas the vertical denture base (VDB) of the DLP group was the largest with 328 ±4 μm. For the trueness RMS value of the cameo surface, the MDB group was the lowest with 50 ±1 μm, whereas the VDB group was the largest with 334 ±24 μm. For the adaptation RMS value of the socketed surface of the denture base, the MDB group was the lowest with 44 μm, whereas the VDB group was the largest with 117 ±2 μm.Within the limits of this in vitro study, the MDB group showed better trueness and socketed surface adaptation than the DLP groups (HDB and VDB).

To evaluate and compare the influence of dissimilar CAD-CAM material on the marginal fitness of endocrown with different cavity depths. Freshly extracted human maxillary first premolar teeth (n = 40) were selected for this study. Teeth were decapitated 2 mm above the cement-enamel junction from proximal surface and endodontic treatment were performed for all teeth. Samples were allocated at two main groups (n = 20), according to cavity depth. Group A: 2 mm cavity depth; Group B: 4 mm cavity depth; and further subdivided into two sub-groups according to material used (n = 10): (A1 and B1) resin-based material; (A2 and B2) ceramic-based material. Teeth were prepared with butt joint margin and 10° internal axial wall divergence. Afterwards, samples scanning was performed using InLab digital scanner. Endocrown restoration fabricated by Sirona Cerec InLab MCXL milling device and adhesively luted with a resin cement (RelyX™ Ultimate ClickerTM, 3 M ESPE). All samples were subjected to thermocycling. After thermocycling, marginal gaps were measured using stereomicroscope at a magnification of 45X. The recorded measurements were collected, scaled and statistically analyzed. A resin-based endocrown showed significantly a smaller vertical marginal gap than ceramic-based, an endocrown with 2-mm cavity depth showed significantly lower marginal gap than one with 4-mm cavity depth. Increasing the cavity depth of endocrown preparation negatively affect the marginal fit. Resin-nanoceramic endocrown showed better marginal fit than glass ceramic endocrown. Both tested CAD/CAM materials showed clinically acceptable vertical marginal gap.

The aim of this study was to evaluate the effectiveness of the combination of Bacillus subtilis TM3 formulation with botanical pesticides in suppressing Fusarium verticilloides infection in corn. The research was carried out at the Plant Pathology Laboratory and the Experimental Farm of Indonesian Cereals Research Institute (ICERI) from February to November 2019. The research consisted of two stages, namely an in vitro test of antagonists of botanical pesticides against F. verticilloides using 5 types of plant extracts namely betel leaf extract, turmeric, galangal, cosmos, and clove leaf. The second stage was to test the effectiveness of the combination of the formulation of B. subtilis TM3 with the best 3 types of plant extracts in vitro testing in suppressing F. verticilloides infection in plants. The results of the in vitro study showed that the plant extracts of betel leaf, clove leaf and galangal had the best inhibitory ability on the mycelia growth of F. verticilloides. Meanwhile, the field test found that the application of the B. subtilis TM3 formulation, either alone or in combination with plant extracts, was able to suppress F. verticilloides infection. The combination of B. subtilis TM3 formulation with betel leaf extract showed the best inhibition of 20% against stem rot disease and 13.33% against corn cob rot. This treatment did not affect production quantitatively, but was able to suppress the decline in seed quality due to F. verticilloides infection. Seeds grown by the Plastic Rolled Paper Test (PRPT) method were not only infected with F. verticilloides, but also infected with other seed-borne pathogens, such as Aspergillus niger and A. falvus. The presence of these two pathogens did not inhibit the growth of F. verticilloides in kernels.

OBJECTIVE The aim of this study was to evaluate the colour stability and mechanical resistance of orthodontic elastic ligature exposed to cigarette smoke. METHODS Four commercial brands were used: Aditek® (GA), Eurodonto® (GE), Morelli® (GM) and Orthometric® (GO). Eight elastic ligature rings (for mechanical analysis) and eight 5×5mm fragments of the material (for colour stability analysis) were separated from each commercial brand for the control group (C) (n=64) and experimental group (E) (n=64). The control group was not exposed to cigarette smoke. Colourimetric status (CIEL*a*b* System) and light transmittance (% transmitted light) were evaluated using Vita Easyshade Compact and CM2600 spectrophotometers, respectively. The mechanical resistance was evaluated using a universal testing machine (EMIC DL), performing tensile testing (speed 5mm/min). The analyses occurred at the following times: T0, before exposure to the smoke; T1, after the 1st exposure; and T2, after the 2nd exposure to cigarette smoke. Comparison between the groups and evaluation of the time effect were performed with the ANOVA/Tukey (a=0.05) and ANOVA-MR tests with Bonferroni correction (α=0.016). RESULTS Significant differences were only observed for colour stability in the GA-E (NBS T2: 15.94±1.88) and GM-E (NBS T2: 16.11±4.54) groups (P

Background To evaluate the quality of in vitro fenestrations during in situ fenestration (ISF) and investigate the differences between needle and laser puncture in current stent-grafts. Methods An in vitro study evaluated the damage created by needle ISF on stent-graft fabrics versus laser ISF. Fenestrations were made in 5 different commercially available stent-grafts, including polyester stent-grafts (Relay, Valiant and Hercules) and expanded polytetrafluoroethylene (ePTFE) stent-grafts (TAG and Ankura). Each stent-graft received fenestration by needle and laser separately, followed by gradual dilation (4 mm, 6 mm, 8 mm, and 10 mm sequentially) of noncompliant balloons. Quantitative and qualitative evaluations including fenestration diameter, area, shape and margins were conducted using light microscopy and scanning electron microscope. Results The primary fenestrations created by needle were slit-like with visible cut-off fibers in polyester stent-grafts and were almost circular with clear margins in ePTFE stent-grafts; those created by laser were squared or elliptical with ragged edges and burned fibers in all the stent-grafts. Fabric debris and toxic particles due to burning of the material were generated during laser-assisted fenestration. The Primary holes in polyester stent-grafts (Relay, Valiant and Hercules) by needle showed smaller area (0.05 mm2 vs. 0.22 mm2, 0.52 mm2 vs. 0.70 mm2 and 0.28 mm2 vs. 0.46 mm2; P 0.05). Ankura stent-graft showed the largest holes with best quality than the others. Conclusions The primary fenestrations were different between needle and laser puncture, laser induced fabric debris and toxic particles release should be cautiously considered. The final fenestrations were similar after gradual balloon dilation.

The aim of this study was to compare locking reconstruction plates with caudobuccally screwed custom mandibular reconstruction plates in bridging lateral mandibular segmental defects. The in vitro study was conducted on 13 polyurethane mandibles. A total of 7 mandibles with lateral segmental defects were bridged with locking reconstruction plates in group I, 6 mandibles with the same standard defect were bridged with caudobuccally screwed customised reconstruction plates in group II. Mean yield displacement, yield load, and displacement at 80 N (Newtons), 100 N, 200 N, 300 N loading were compared among the 2 groups. The mean (SD) displacement for Group I was 11.27 (3.6) mm, Group II was 21.08 (2.5) mm. Group II had significantly greater (p=0.0001) displacement when compared with Group I. The mean (SD) force before failure for Group I was 638.4 N (127.2), Group II was 1398. 3 N (162.7). Group II withstood significantly greater force than Group I (p=0.0001). The study reveals that the caudobuccally screwed custom reconstruction plates can significantly enhance yield load as preserving the preoperative shape of the face and mandible.

Summary Objective The aim of this in vitro study was to evaluate the effects of enamel deproteinization on the shear bond strength of a self-etching primer Transbond Plus™(TBP), with different application times of sodium hypochlorite (NaOCl 5.25%), primarily and secondarily on the adhesive remnant index score. Materials and methods One hundred twenty-five freshly extracted human premolars were randomly and blindly divided into five groups according to the enamel surface preparation, as follows (n = 25): group 1(control): Etching with 37% phosphoric acid for 15 seconds + Bonding; group 2 (control): TBP™ without NaOCl, group 3: 60 seconds NaOCl + TBP™, group 4: 30 seconds NaOCl + TBP™, group 5: 15 seconds NaOCl + TBP™. The same composite resin was used (Transbond XT™) to bond the orthodontic metal brackets. After the immersion of the teeth in distilled water at 37 °C for 24 hours the shear bond strength was measured using the universal testing machine and the adhesive remnant index score (ARI) was evaluated under an optical microscope (25 × ). Results The mean SBS values (in MPa) of the groups were respectively: group 1: 13.03 ± 5.36; group 2: 12.28 ± 3.06; group 3: 12.38 ± 4.55; group 4: 12.98 ± 5.76; and group 5: 11.73 ± 5.67. Enamel deproteinization increased the SBS for groups 3 and 4, but no statistically significant difference was found between the five groups (P = 0.883). Group 1 showed the highest ARI scores, with 52% of the teeth retaining all the adhesive (score 3). However, for all the other groups, scores 0 and 1 were predominant, with less than half of the adhesive or no adhesive at all remaining on the teeth. Conclusions Enamel deproteinization with sodium hypochlorite (5.25%) and the variation of its application time has no effect on the SBS of the self-etching primer Transbond Plus ™.

Malpositioning of implants is one of the main factors leading to hard- and soft-tissue deficiencies. Whether static computer-guided implant placement increases accuracy and prevents malpositioning is unclear.The purpose of this in vitro study was to determine accuracy defined by trueness and precision (according to International Organization for Standardization 5725) of computer-assisted implant surgery (fully guided and partially guided) in comparison with freehand single implant placement.Implants (n=20) were placed fully guided (sleeve-bone distance of 2, 4, or 6 mm), partially guided (guide used for pilot drill), or free hand in identical replicas produced from a cone beam computed tomography (CBCT) scan of a partially edentulous patient. The achieved implant position was digitized by using a laboratory scanner and compared with the planned position. Trueness (planned versus actual position) and precision (difference among implants) were determined. The 3D-offset at the crest of the implant (root mean square between virtual preoperative planning and postoperative standard tessellation language file) was defined as the primary outcome parameter. The means, standard deviation, and 95% confidence intervals were analyzed statistically with 1-way ANOVA and the Scheffé procedure.Fully guided implant surgery achieved significantly lower 3D deviations between the planned and actual implant position with 0.22 ±0.07 mm (2-mm sleeve-bone distance) than partially guided 0.69 ±0.15 mm and freehand placement 0.80 ±0.35 mm at the crest (P.001). The distance among the implants in each group was again lowest in the fully guided group and highest in the freehand group.The static computer-assisted implant surgery showed high trueness and precision. The closer the sleeve to the bone, the more accurate and precise the method. Freehand implant placement was less accurate and precise than computer-assisted implant surgery (partially or fully).

Introduction: The aim of the present study was to investigate the influence of root canal preparation size and taper of middle mesial (MM) canals on fracture resistance of mandibular molars. Methods: Fifty-five mandibular molar teeth having an MM canal were selected based on the cone-beam computed tomographic analysis. After the decoronation and distal root separation procedure, the lengths of the mesial roots were standardized to 13 mm. The specimens were randomly distributed into 5 groups (n = 11). Mesiobuccal and mesiolingual canals were prepared up to size 30.06 using VDW.ROTATE rotary files (VDW, Munich, Germany). The MM canal was prepared up to size 25.04, 25.06, 30.04, and 30.06, respectively. No preparation was done in the MM canal in the control group. After the irrigation protocol, the canals were obturated with the single-cone technique. A thin layer of silicone coated specimens was embedded in acrylic resin and subjected to a fracture strength test by a universal testing machine. A vertical force was applied to the roots until they fracture. Statistical analysis was performed with 1-way analysis of variance and post hoc Duncan tests (P = .05). Results: There was no significant difference between group 25.04 and the control group, but the fracture strengths of these groups were found to be significantly higher than that of groups 25.06, 30.04, and 30.06 (P , .05). Conclusions: Within the limitations of this study, we concluded that increasing the apical diameter and taper in the MM canal reduces the fracture strength of mandibular molar teeth. Among the tested instrumentation sizes, fracture strength decreased significantly when greater than 25.04 instrumentation sizes were chosen. (J Endod 2021;47:1467-1471.)

Introduction: Species of the Salvia genus are aromatic herbs and traditionally used for many medicinal purposes in Anatolia. The genus has produced an extraordinarily large number of beneficial secondary metabolites belonging to numerous chemical groups. Salvia pisidica is an endemic plant of southwest Anatolia, the dried parts of which are used as herbal tea and local materia medica. Methods: The composition of endemic S. pisidica essential oil was determined through GC-MS studies. In vitro cytotoxicity activity and apoptosis analysis were investigated by MTT assay, q-PCR and Annexin V staining experiments. Results: Our results showed that 1,8 cineole (19.15 %) camphor (18.12 %) and γ-gurjunene (8.58 %) were the major constituents of the essential oil. It showed cytotoxic effects on the human breast cancer MCF-7, colon carcinoma Caco-2, hepatocyte carcinoma HepG2, and prostate carcinoma LnCap. The results of q-PCR and image-cytometer analysis showed that the essential oil caused induction of apoptosis by intrinsic and extrinsic pathways in all cancer cell lines. Conclusion: S. pisidica essential oil demonstrates considerable cytotoxic activity due to an apoptosis-related mechanism, suggesting that their bioactive components could be used as natural anticancer substances. © 2023 Elsevier GmbH

Objective The objective of this study was to assess the effects of 3 T magnetic resonance imaging (MRI) on the microleakage of 5 restorative materials. Methods In total, 100 maxillary molars were randomly assigned to 5 groups (n = 20) for restoration with 5 different materials: amalgam, light-cured glass-ionomer cement, feldspathic porcelain fused to metal, pressed lithium disilicate glass ceramic, and composite resin. In each group, 10 specimens were subjected to MRI, and 10 specimens served as controls with no MRI exposure. Standardized class V cavities were prepared with occlusal margins terminating in enamel and gingival margins terminating in dentin. Microleakage penetration at the enamel and dentin margins was calculated for each group. A chi-square test was used for intergroup comparisons. Statistical significance was established at P Results Microleakage penetration did not differ significantly between specimens subjected to MRI and the controls for any restoration (P ≥ .362 for the enamel margin, P ≥ .067 for the dentin margin) or between specimens treated with different restorative materials (P ≥ .355). No significant differences in microleakage were discovered between the enamel and dentin margins of any of the restorative groups (P ≥ .236). Conclusion MRI had no effect on the microleakage of the 5 restorative materials.

The introduction of intraoral scanners has increased the use of digital technology in dental procedures. However, data on the accuracy of abutment scans according to the distance between the adjacent tooth and the abutment are lacking.The purpose of this in vitro study was to compare the 3D accuracy of abutment scans according to the distance between the adjacent tooth and the abutment.A right maxillary first molar was removed and scanned with an industrial 3D scanner, and the image was extracted as a standard tessellation language (STL) file. Six virtual models with 1-mm, 1.5-mm, 2-mm, 2.5-mm, 3-mm, and 3.5-mm spacing between abutment teeth and adjacent teeth were fabricated with an industrial computer-aided design (CAD) software program. Then, 6 master models were fabricated with a 3D printer and copied into dental gypsum. The replicated models (reference models) were scanned 20 times with an intraoral scanner (CS3600); the resulting model was referred to as the CAD test model. The adjacent teeth of the reference models were deleted, and the models were scanned with a laboratory scanner; the resulting model was referred to as the CAD reference model. The CAD reference model was used to measure the scan accuracy in 4 directions (buccal, lingual, mesial, and distal) and 4 areas (occlusal, angle, axial, and margin) by using a 3D inspection software program. The Friedman nonparametric test (α=.05) was used for comparison, and post hoc testing was performed by using the Mann-Whitney U-test and Bonferroni correction method (direction and area variables; α=.0008, distance variable; α=.0003).The buccal, lingual, mesial, and distal directions of the abutment were significantly different according to distance (P.001). The margin, axial, angle, and occlusal regions of the abutment were also significantly different according to distance (P.001).The distance between the abutment teeth and adjacent teeth affected the accuracy of the abutment scan. In intraoral scanning, when the distance between the abutment teeth and the adjacent teeth is more than 1.5 mm, the scan error does not increase, and more accurate scan data can be obtained.

Summary Objective The present study was performed to affirm surface characterization, as well as to compare the effect of coating of stainless-steel (SS) orthodontic brackets and wires by nanoparticles Chitosan (CTS) or Zinc oxide (ZnO) during friction. Material and methods Seventy SS brackets for the upper right central incisors with a 0.022–inch system and seventy 0.019 × 0.025-inch SS rectangular wires, with and without ZnO and CTS nanoparticle coating, were used. Coating was analysed by SEM. A universal testing machine was used to calculate the friction between the wires and brackets. Statistical analysis was performed using one-way ANOVA and Tukey's tests. Results Significant differences were detected between coated and uncoated wires and brackets for friction with either ZnO or CTS nanoparticles. The mean values of the wires and brackets coated with ZnO and CTS nanoparticles were 0.64 ± 0.24 N and 0.85 ± 0.23 N, respectively, while they were 1.79 ± 0.61 N for the uncoated group. In addition, there was a significant decrease of about 64% and 53% found after coating with ZnO and CTS nanoparticles, respectively. The results of CTS nanoparticle coating were consistent with those of ZnO nanoparticles. Conclusions Friction force decreased significantly after coating of CTS or ZnO nanoparticles. These nanoparticles provide an opportunity to reduce friction during tooth movement, resulting in better anchorage control, reduced treatment time and risk of root resorption.

Introduction This research studies and compares the shaping ability of WaveOne Gold (WG; Dentsply Tulsa Dental Specialties, Tulsa, OK), the Reciproc Blue (RB; VDW, Munich, Germany), TRUShape (TS, Dentsply Tulsa Dental Specialties), XP-endo Shaper (XP; FKG, La Chaux-de-Fonds, Switzerland), iRace (IR, FKG), and TruNatomy (TN; Dentsply Sirona, Ballaigues, Switzerland) in the preparation of moderately curved canals and using micro–computed tomographic technology. Methods Sixty lower molars with 2 mesial canals were randomly distributed into 6 groups of 10 molars and 20 canals per group (n = 20). Specimens were scanned before and after preparation using the SkyScan 1275 (Bruker microCT, Kontich, Belgium). Group 1 was treated with WG, group 2 with RB, group 3 with TS, group 4 with XP, group 5 with IR, and group 6 with TN. After instrumentation, researchers quantified the changes produced in the canal geometry in terms of surface, volume, structure thickness, surface convexity index, structure model index, percentage of surface touched, and centroids. Wilcoxon and analysis of variance tests were performed to compare the values before and after preparation and the differences between groups. The significance level was established at 5%. Results There were no significant differences between WG and RB (P > .05) and between TN and XP (P > .05). TN had significant differences with WG, RB, TS, and IR (P .05). Conclusions WG and RB and TN and XP had similar shaping effectivity. TS and WG touched the highest percentages of canal surfaces (81% and 73%, respectively) but produced the biggest changes in the canal anatomy. TN and XP better kept the canal anatomy, but TN touched the lowest percentage of canal surface (50%). All the files used were able to clean and to shape moderately curved canals with minimal apical transportation.

Statement of problem Additive manufacturing has been proposed for the fabrication of occlusal devices. However, information about the mechanical properties of additively manufactured devices is lacking. Purpose The purpose of this in vitro study was to evaluate the influence of the postpolymerization unit and artificial aging on the Martens hardness (HM) and indentation modulus (EIT) of different 3D-printed materials in comparison with a conventionally milled material. Material and methods Thirty disks (20 mm in diameter and 5 mm in thickness) were additively manufactured (D20 II, Rapidshape & Form 2) for each 3D-printed material (NextDent Splint, Formlabs Dental LT Clear, and Freeprint Splint). As a control, 10 disks of the same thickness were cut from a conventionally milled material (Temp Premium). Each specimen was measured for HM and EIT (ZHU 0,2) after fabrication. The specimens were stored in water at 37 °C and measured again after 2 and 4 weeks. The data were analyzed statistically by using the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests (adjusted by Bonferroni correction α=.05/27=.002). Results The highest influence on HM parameters was shown by artificial aging (partial eta squared: HM: ηP2=0.840, EIT: ηP2=0.855, P Conclusions HM parameters of additively manufactured occlusal devices depend on postpolymerization strategy. Otoflash and Printbox result in higher HM and EIT values. The 3D-printed materials are more prone to artificial aging than the control group, which brings into question their long-term service.

Synthetic bone graft has gained considerable attention because of an increase in the aged population. In the present study, a biphasic bone graft composed of hydroxyapatite (HAp) and calcium sulfate (CS) is prepared using a gel-foaming technique. The gel is prepared at a temperature as low as 35 °C; many pores are introduced into the gel through an agitation process. The foamed gel can be cut into any shape and size. After sintering, the porosity of the biphasic bone graft is approximately 70%. Depending on the HAp/CS ratio, the amount of macropores and micropores can be tailored. The macropores of approximately 130 μm diameter are interconnected with each other through openings of 40 μm size. The biphasic bone graft exhibits no cytotoxicity; preosteoblast cells can adhere and proliferate on the surface of the fabricated bone graft. However, migration of these cells into the bone graft is considerably limited in the in vitro study. When the biphasic bone graft is implanted into the distal femur of rats, with the combined effect of osteoblast and osteoclast cells, more than 90% of the bone graft is degraded after 3 months. New trabeculae bone and bone marrow are observed within the bone defect. The HAp/CS composite can thus be used as degradable bone grafts.

Summary Objective White spot lesion (WSL) is one of the most important complications of fixed orthodontic treatment. Many methods have been studied to prevent this problem. This study is aimed to investigate the effect of high concentration nano-hydroxyapatite (nHAP) on shear bond strength (SBS) of metal brackets and Adhesive Remnant Index (ARI) score in different preparation methods. Material and methods Sixty human premolars, which were extracted for orthodontic reasons were included in this in vitro study. The teeth were randomly divided into 4 groups of 15 each: one control group and three nHAP groups. After applying nHAP for 2 to 3 minutes daily for 10 days, the groups 2 to 4 underwent sandblasting using 50 μm aluminium oxide and 30 seconds etching, 60 and 30 seconds etching, respectively, and the brackets were then bonded to the teeth. After debonding, SBS and ARI scores were recorded. Data were analysed using the ANOVA test and posthoc test for pairwise comparisons. Results No significant difference was observed in SBS between the control group and the nHAP groups. The sandblasted teeth showed significantly higher SBS than the 30 seconds etching after nHAP application (P = 0.02). The teeth etched for 60 seconds showed a significantly higher ARI score than the 30 seconds etched teeth with (P = 0.003) or without (P Conclusions The use of nHAP before bracket bonding can be considered as a caries preventive method since it did not compromise the SBS. Sixty seconds etching is recommended for less likely damage to the enamel after debonding.

No clinical studies have evaluated shear bond strength and the clinical failure rates of the rebonded metallic brackets following different enamel-reconditioning methods. The objective of the study was to compare the in vivo clinical failure rate and the in vitro rebond strength of bonded brackets following two enamel surface preparation methods.For the in vitro study, 45 extracted human premolars were etched; brackets were bonded using light-cured composite resin. Forty-five premolars were divided into three groups (15 in each group): the initial bonding group (IB group), the rebonding group in which enamel was reconditioned using sandblasting before acid etching (SBE group), and the rebonding group in which enamel was reconditioned using acid etching only (E group). For the in vivo study, 80 premolars in 20 patients (13-18 years old) were rebonded using the same procedures in the SBE group and E group. The two methods were used in all patients using a split-mouth design. The number of failing brackets was quantified over 6 months. Differences were statistically analyzed by one-way analysis of variance, followed by post hoc tests.The mean shear bond strength for the IB, SBE, and E groups was 19.38, 22.37, and 17.31 MPa, respectively. A significant difference was observed in the bond strength of the three evaluated groups (P0.001). The differences in the bond strength were significant between the IB group and the SBE group, as well as between the SBE group and the E group. The clinical failure rate for bonded brackets was 10% in the SBE group, and 25% in the E group and this difference was statistically significant (P0.001).Reconditioning of enamel surfaces using both intraoral air abrasion and etching in the rebonding process led to higher rebond strength than using acid etching alone and even higher than the initial brackets bonding. This trial was retrospectively registered at ClinicalTrials.gov (ID: NCT04606043).

Background To prevent alcohol-based chlorhexidine from reaching the cerebrospinal fluid, it is recommended that the antiseptic solution be allowed to dry before skin palpation or puncture. However, no guidelines specify a drying time interval. Manufacturers recommend 3 min of air drying, based upon the isopropyl alcohol component. Therefore, to fill this knowledge gap, we designed a simulation study to investigate the incidence of primary chlorhexidine transfer from skin to gloves following three drying time intervals. We also investigated the incidence of secondary chlorhexidine transfer from gloves to another surface following one drying time interval. Methods An alcohol-based chlorhexidine antiseptic solution with dye, ChloraPrep®, was applied to the skin of the lumbar region of 20 volunteers. Cotton-tipped applicators wrapped in material from gloves were taken from the application area at 3, 4, 5, and 10 min following application. Transfer of chlorhexidine from skin to gloves, and gloves to another medium, was assessed through a chemical assay that produced a color change when chlorhexidine was present on the sample. Results The incidence of primary chlorhexidine transfer from skin to gloves at 3, 4 and 10 min following application was 99.5%, 99.4%, and 99.6%, respectively. The incidence of secondary chlorhexidine transfer from gloves to another surface was 68.9%. Conclusion Gloves are routinely contaminated with chlorhexidine during central neuraxial blockade. The high incidence of secondary transfer in our simulation suggests a pathway by which chlorhexidine may gain access to the neuraxial space.

Layer thickness in additive manufacturing has stair-step effects that greatly affect the accuracy of the definitive prosthesis. Although the layer thickness can be set, insufficient data comparing and analyzing the accuracy of the fabricated prosthesis after adjusting the layer thickness are available.The purpose of this in vitro study was to evaluate and compare the accuracy of trial dentures fabricated with different layer thicknesses by using stereolithography (SLA) apparatus.A maxillary complete edentulous cast was duplicated with silicone material to make a master gypsum cast which was scanned by using a laboratory scanner and saved as a standard tessellation language (STL) file. This was exported into a computer-aided design software program to produce and store the trial denture. Twenty dentures were fabricated according to the set layer thicknesses (50 μm and 100 μm) by using the SLA. The trueness was measured by scanning the intaglio and cameo surfaces to find the best overlap with the reference model to obtain the root mean square value. The precision was evaluated based on the RMS value gained by superimposing the identical scan data from each group and using the combination formula. The Mann-Whitney U-test was used to confirm significant differences among the groups (α=.05).The trueness of the 50-μm-SLA trial denture and the 100-μm-SLA trial denture was significantly different for the intaglio and cameo surfaces (P.05). However, the intaglio surface did not show a statistically significant difference (P=.987) for precision, but the cameo surface did (P.05).It is clinically more appropriate to set the layer thickness to 100 μm rather than 50 μm for the fabrication of accurate trial dentures by using SLA.

Statement of problem Soft-tissue attachment to different surfaces may play a pivotal role in the long-term success of dental implants. However, studies on the issue, especially on newer materials, are sparse. Purpose The purpose of this in vitro study was to evaluate the viability and adhesion of human gingival fibroblasts (HGFs) on different implant abutment materials with specific surface modifications. Material and methods One hundred and fifty specimens in 6 experimental groups were evaluated: smooth-machined titanium alloy (Ti), laser-modified titanium (TiL), smooth-machined polyetheretherketone (PEEK) (P), laser-modified PEEK (PL), plasma-treated PEEK (PP), laser- and plasma-treated PEEK (PLP). Machined Ti was considered as the control group. Surface roughness (Sa), water contact angle (WCA), and X-ray photoelectron spectroscopy (XPS) were measured. HGF attachment and proliferation were observed at 1, 3, and 7 days after cell seeding. Comparison of the means among the groups was performed with 1-way analysis of variance (ANOVA) with post hoc comparison using the Tukey test (α=.05). Results Sa values of the laser modified groups were significantly higher than those of the nonmodified (smooth-machined) groups (P .05). On the first and third days of proliferation, the plasma sprayed groups (PP, PLP) showed significantly greater proliferation than all experimental groups (P .05). Conclusions Laser-modified titanium and PEEK surfaces led to guided gingival fibroblast attachment. Plasma treatment of PEEK surfaces increased the wettability of this polymer and improved proliferation of HGF.

Statement of problem The release of titanium (Ti) particles from the surface of endosseous dental implants is not well understood. Purpose The purpose of this in vitro study was to evaluate the effect of thermocycling on the surface texture and release of Ti particles from the surface of dental implants. Material and methods Three MSI dental implants and 3 Ti alloy (Ti6Al4V) plates were divided into 6 subgroups (n=3). Specimens in each group were subjected to 0 (control group), 100, 200, 500, 1000, and 2000 thermocycles. After each cycling process, artificial saliva was collected, and the concentrations of released Ti particles were quantified by inductively coupled plasma-mass spectrophotometry (ICP-MS). The surfaces of the dental implants and Ti plates were evaluated before and after thermocycling by scanning electron microscopy (SEM), and SEM images were analyzed by using the ImageJ software program. Data were analyzed by mixed-model ANOVA and post hoc Tukey tests (α=.05). Results The greatest Ti release was seen after 2000 thermocycles. After increasing the number of cycles, additional Ti particles were released. SEM images of the surfaces of the dental implants and Ti plates displayed significant changes in surface texture. Conclusions Thermocycling continuously removed the protective TiO2 layer on the surface of dental implants, resulting in the release of Ti particles. The surface treatment and texture did not affect the release of Ti particles.

Measuring both the trueness and precision of an intraoral scanner (IOS) will provide a thorough understanding of its accuracy.The purpose of this in vitro study was to measure the complete-arch trueness and precision of 3 commercially available intraoral scanners equipped with the latest software version and compare them by using a laboratory scanner as reference.Nineteen maxillary and 19 mandibular completely dentate stone casts previously acquired from 19 patients by using a polyvinyl siloxane (PVS) dual mix impression and stock trays were scanned with 3 intraoral scanners (TRIOS 3; 3Shape A/S, i500; Medit, and Emerald; Planmeca) using their latest software versions. The same casts were also scanned with a laboratory scanner (E3; 3Shape A/S) that served as the reference scanner. Files were exported in standard tessellation language (STL) format and inserted into a metrology 3D mesh comparison software program (CloudCompare).In terms of trueness, a significant difference was found among the scanners (F (2.37)=239.7, P.001). Planmeca Emerald had significantly lower trueness values than either the Medit i500 (P.001) or the 3Shape A/S TRIOS 3 (P.001). No significant difference in trueness was found between the Medit i500 and the 3Shape A/S TRIOS 3 scanner (P=.365). In terms of precision, a significant difference was found among the scanners (F (2.89)=301.2, P.001). The 3Shape A/S TRIOS 3 scanner was significantly more precise than the other scanners (P.001 for both the Medit i500 and Planmeca Emerald). The Planmeca scanner was significantly more precise than the Medit i500 scanner (P.001). Concerning the ability of the scanners to reproduce the files of the reference scanner without overestimation or underestimation, the Medit i500 produced files that significantly underestimated the reference scanner's files (t (37)=-12.4, P.001). The other scanners did not significantly either underestimate or overestimate the files of the standard (t (37)=-1.91, P=.062 for the TRIOS 3 and t (37)=1.64, P=.101 for the Planmeca) CONCLUSIONS: With regard to completely dentate arch trueness, the Planmeca Emerald IOS had statistically lower trueness. With regard to complete dentate arch precision, the 3Shape A/S TRIOS 3 IOS was the statistically more precise scanner. With regard to reference scanner file estimation, the Medit i500 IOS produced files that significantly underestimated the reference scanner files. All 3 tested scanners exhibited a completely dentate arch average accuracy below 100 μm in vitro.

Aim This in vitro study intend to compare the cleaning effectiveness of Protaper universal sequence with reciprocating F2 Protaper and single rotary file One shape. Materials and method 30 extracted human 1st mandibular molars were chosen for the analysis. Three NiTi file systems were used for mechanical preparation, ProTaper full sequence in rotary motion, single F2 Protaper file used in reciprocating motion, and One shape single file used in a circular motion. Irrigation was carried out after each instrument use using 5 ml of 5% NaOCl followed by normal saline. The root canal surface was evaluated at three different areas (coronal, middle and apical thirds) using Scanning Electron Microscopy. Debris and the Smear layer were evaluated. Data were analyzed statistically using the Friedman test and Kruskal–Wallis test (p ≤ 0.05). Results A statistically significant difference (p ≤ 0.05) was observed in the debris score of the Protaper universal group when the 3 thirds of the root were compared. Intergroup comparisons confirmed a statistically significant difference at the coronal and apical third of the roots when debris scores were evaluated. Intragroup comparison for the smear layer demonstrated a statistically significant difference (p ≤ 0.05) at all the 3 levels of the radicular canal for the 3 groups studied. Intergroup comparisons revealed a statistically significant difference (p ≤ 0.05) in the middle and apical 1/3rd when the smear layer was evaluated. Conclusion The Protaper full sequence group provided better results than Single F2 ProTaper and One shape groups when debris and smear layer removal was investigated.

Summary Elastomeric chains are widely used by orthodontists for incisor retraction and space closure. However, force degradation and permanent deformation are expected to occur. Objectives The present study was designed to compare the force degradation of closed, open, grey and transparent power chains from four orthodontic companies (American orthodontics® (AO®), Dentsply®, Ormco® and Rocky Mountain Orthodontics® (RMO®)) over time. Materials and methods Universal testing machine was used to measure the force of the power chains elongated to 25 mm at 0 hours, and after storage in artificial saliva at 24 hours, 1 week, 2 weeks, 3 weeks, and 4 weeks. A Tukey's honestly significant difference test was performed. Results Most of the power chains showed less than 30% of force decay at 24 hours of elongation. The AO® transparent open elastomeric chains presented the lowest percentage of force remaining at almost all times: 24 hours (58.9%), 1 week (67.7%), 2 weeks (43.2%), 3 weeks (72.4%), and 4 weeks (63%). Most of the power chains had an increase of force measured after 2 weeks of storage in artificial saliva. Three of the sixteen groups (Ormco® grey open, RMO® grey and transparent closed) displayed an increase in the force at 4 weeks of elongation compared to the force registered at 0 hours. Conclusion The results indicated that the force generated by elastomeric chains at 4 weeks remains optimal for a physiologic tooth movement.

Aim The aim of this study was to evaluate the potential remineralization effect of Novamine and Er:YAG laser on artificial enamel lesions in primary teeth. Materials and methods In this in vitro study, 30 sound buccal and lingual surfaces of human primary canines were randomly divided (6 per group) into 5 groups (Novamine, Laser, Novamine+ Laser, Positive control, and a negative control). Remineralization agents were applied for 1 min to teeth using a rubber cup after creating artificially demineralised lesions. EDX analysis was performed to evaluate the Ca/P ratio and take Scanning electron microscope images. Results Data were analyzed using Kruskal Wallis analysis. Ca/P ratio was higher in all 4 groups than the negative control group, and higher in Novamine+ Laser group than the positive control group with a statistically significant difference between groups. Overall Ca/P ratio was found to be highest in the Novamine group followed by the laser then positive control group. There were no significant differences between groups regard to Ca/P Ratios. Conclusion Based on these result Er:YAG laser combined with Novamine was provided the greatest contribution to remineralization process of primary teeth.

Summary Introduction Effects of different oral hygiene controls on force kinetics of memory elastic chains are not assessed adequately or in the case of many oral care products, non-existent. This study assessed these. Material and methods This in-vitro study was performed on 647 observations of 132 elastic chains assessed at 5 intervals. In each of the treatments (artificial saliva, fluoride, OralB mouthrinse, whitening OralB mouthrinse, toothpaste, and whitening toothpaste), 11 memory and 11 conventional chains were tested. Chains were stretched for 100%; their initial force was measured (g), and immersed in artificial saliva at 37 °C. For treatments other than artificial saliva, the specimens were removed from the saliva twice daily and the main treatment was applied. After washing with distilled water, they were immersed back in artificial saliva. At the days 1st, 7th, 14th, and 28th, their force was re-measured. Data were analysed statistically (α = 0.05). Results Force degradation of elastic chains was observed in both memory/conventional types (P = 0.000) although memory chains showed slightly less declines especially in the beginning days. The interaction of treatment and time was significant (P = 0.000) meaning that different treatments caused different rates of force decay, with fluoride having the fastest drop rate followed by whitening toothpaste. However, the difference among 5 intervals of time was not significant (P = 0.569). When elastic types were assessed separately, this variable as well became significant (P ≤ 0.002). One-sample t-test showed that all final residual forces (28th day) were either above 150 g or at its level. Conclusion Chain force degrades over time but stays sufficient for bodily tooth movement after 4 weeks. Memory chains are preferable as they provide greater forces for longer durations. Fluoride mouthwash followed by whitening toothpaste cause the most rapid declines. Both chain types still retained adequate forces after 4 weeks, even after treatment with fluoride or whitening toothpaste.

Summary Background Many antiseptics have been used to treat wounds. Aim To compare the microbicidal efficacy of ClHO (Clortech®) with other antiseptics used on wounds, healthy skin and mucous membranes. Methods The microbicidal efficacy of 13 antiseptic products on eight micro-organisms (three Gram-positive; three Gram-negative; two yeasts) inoculated on organic germ-carriers was studied. In addition, the loss of efficacy against Staphylococcus aureus and Pseudomonas aeruginosa with biofilm was assessed with the six best-performing products. Findings Chlorhexidine (1%) had the highest microbicidal effect at 1 min. At 5 min, 500 and 1500 mg/L ClHO showed similar, or better, activity than the other antiseptics studied. The ClHO concentration of 300 mg/L achieved this same efficacy at 10 min. The product that lost the most efficacy due to biofilm was 1% chlorhexidine, while 1% PVP-I and ClHO at either 300 or 500 mg/L were moderately affected by biofilm. The most effective in the presence of biofilm was ClHO at 1500 mg/L. Conclusions ClHO at medium–low concentrations (300 or 500 mg/L) is a good antiseptic that can be used on wounds and mucous membranes for 5–10 min. Lower concentrations of ClHO, as well as of the other antiseptics studied, were less effective or more altered by the biofilm. ClHO at a concentration of 1500 mg/L is very effective in the presence or absence of biofilm that can be used on healthy skin for 5 min.

Summary Objective The present study aimed to compare the force of aesthetic wires and their non-aesthetic equivalents from two commercial brands at different displacement points, during the unloading phase at 36 °C. Materials and methods Forty samples (n = 10) were assessed, which were presented in two groups of aesthetic wires and two groups of non-aesthetic wires from the brands GAC® (Dentsply GAC® International, NY, USA) and Aditek®(Cravinhos, SP, Brazil), with 0.016-inch gauge. The orthodontic wires were maintained at a temperature of 36 °C throughout the experiment and they were subjected to the three-point bending test at a speed of 1 mm/min. The unloading values were recorded as 0.5, 1.5, and 2.5 mm of displacement. The data were subjected to Student's t-test and unequal variance t test, at 5% significance level. Results During the unloading phase, the mean force was significantly higher for aesthetic wires than non-aesthetic ones, in the deflection of 2.5 mm, presenting values means of 2.25 N (P = .0213). In deflections of 0.5 mm and 1.5 mm, the orthodontic archwires did not show significant differences in force between the thermally activated wires with aesthetic coating and their non-aesthetic equivalents (P ≥ 0.05). Conclusion It is concluded that during the unloading phase at a temperature of 36 °C, the orthodontic archwires analyzed did not show significant difference in force between thermally activated wires with aesthetic coating and their non-aesthetic equivalents at most displacement points analysed, except for the deflection of 2.5 mm, which showed higher values.

BACKGROUND: The TMT-1 joint arthrodesis is a common repair for severe hallux valgus. Two crossing interfragmental screws, usually titanium or steel, and a locking plate or a plate with a compression screw are the most common fixation methods for first TMT joint arthrodesis. The qualities of an ideal fixation material include adequate strength and rigidity, biocompatibility, lack of interference with bone healing, lack of visibility and palpability, and a low risk of surgical removal. We sought to determine whether bioabsorbable cannulated screws would perform as well as titanium screws in anatomical models. METHODS: Identical anatomical TMT-1 arthrodesis was created with a saw by making a straight cut in 30 anatomical models (Sawbone®). The bioabsorbable and titanium screws were placed one at a time in exactly the same location in each model according to careful measurements. All 30 models were analyzed with a material testing machine (MTS Insight 30, Eden Prairie, USA). Each model was oriented 15° to the platform to simulate its position to the ground during mid-stance. RESULTS: In the single-cycle load-to-failure test, the mean yield load was 61.4 N ± 5.7 N (range, 50.1 N–70.3 N) in the bioabsorbable screw group and 81.2 N ± 12 N (range, 61.7 N–113.4 N) in the titanium screw group (P

Polymethylmethacrylate (PMMA) represents the current gold standard as an antibiotic delivery carrier in orthopaedic surgery. Despite the accepted use of local antibiotic carriers, there aren't any conclusive data comparing PMMA to Bone Graft Substitutes. The aim of this in vitro study was to compare the elution profile of gentamicin from various preparations of PMMA cements and Herafill beads. All cements had high initial elution during the first hour which then slowly decreased, Herafill beads on the other hand showed its higher elution around the eighth hour. Herafill, in general, presented the highest elution of gentamicin regardless of its input amount.

The use of cold atmospheric pressure plasma (CAPP) as a bacterial decontaminant for chronic wounds has shown good results. The purpose of this in vitro study was to evaluate the bactericidal effects of CAPP on the cancellous area of the bone. Sterile glass slides and processed sterile human bone allografts 1, 2, 3, and 4mm thick were used for initial contamination and further CAPP treatment. Each block was contaminated with Staphylococcus aureus suspension on one side. Each slide was turned 180° and treated on the reverse side. The bacterial count in colony-forming units (CFU) was then measured and compared with that of a control group, and the bactericidal effects of CAPP in relation to bone density evaluated. A significant reduction in count was measured between treated and untreated groups (groups A-D: p0.01 and group E: p=0.04). A strong positive linear relation was found between bone density and the S aureus count (r=0.844, p=0.156). Treatment with CAPP had a bactericidal effect on bone structures with a penetration depth of up to 4mm. It might be used for all diseases involving infected bone, and so extends the existing range of treatments.

Objectives One of the causes of dental caries that occurs due to orthodontic treatment is the lack of antibacterial properties in orthodontic adhesive. This study was designated to investigate the effect of orthodontic resin modified by incorporating Nano Cinnamon powder on the shear bond strength of orthodontic brackets. Materials and methods Heliosit Orthodontic Resin, a photo-activated light cure resin was modified by the addition of Cinnamon in the form of Nano particle powder. Twenty uniform disks were made, 5 as a control and 5 for each concentration of the 1%, 3% and 5% wt/wt Cinnamon modified resin. Their antimicrobial activity against Streptococcus Mutans was tested using the disk diffusion method. Then, the most effective concentration of the modified resin was used to bond metal orthodontic brackets to human extracted premolars. The universal testing machine was used to record the shear bond strength of the control and the modified resin. Also, the adhesive remnant index was measured. Results Disc diffusion method showed that the 3% wt/wt Cinnamon powder modified resin was more effective than 1% with a larger bacterial inhibition zone. Shear bond strengths of the control were 8.50 MPa and 7.20 MPa for the 3% Cinnamon modified resin with no significant difference between them. Also, no significant difference was recorded in the adhesive remnant index scores between the control and the modified resin groups. Conclusion Findings of this study revealed that the incorporation of 3% Cinnamon Nano particles in orthodontic resin produced an antibacterial effect against Streptococcus mutans without compromising the shear bond strength. Clinical relevance Incorporation of Cinnamon Nano particles in orthodontic resin may reduce caries formation around brackets during treatment course.

Study Objective To determine the ability of tissue containment systems to prevent leakage of cancer cell surrogates when subjected to forces encountered during power morcellation procedures. Design In vitro study. Setting Medical device research laboratory. Interventions Samples from 7 different legally marketed tissue containment bags (1 of which is indicated for power morcellation) were subjected to dye and bacteriophage penetration tests at pressures ranging from 0.5 to 50 times the insufflation pressure. The minimum pressure required to cause bag leakage was measured. Subsequently, the morcellation leakage safety factor for each bag was determined as the ratio of the minimum leakage pressure of the bag to the total pressure contributed from insufflation pressure and mechanical forces acting during the power morcellation procedure. Measurement and Main Results The leakage performance of the bags varied markedly from brand to brand. No correlation was found between leakage pressure and the bag material or the total bag thickness. The leakage pressures ranged from 26 mmHg to >1293 mmHg for the 7 bags, and safety factors ranged from 1 to 50 when only the insufflation pressure was considered. However, if the morcellation forces were included in the calculation, the safety factor dropped by 6-fold for all brands and dropped below 1, indicating likelihood of leakage, for 2 of the 7 brands. Conclusion This study provides a mechanism for more realistically simulating the conditions experienced by containment bags during morcellation and quantifying the level of safety provided by the bags.

Summary Objectives The aim of this investigation was (1) to compare the effects of cold-hardening bending and direct electric resistance heat treatment (DERHT) methods; and (2) to compare the effects of offsets and angulations on the mechanical properties and thermal analysis of NiTi alloy archwire. Methods Nickel-titanium (NiTi) archwires (Ormco, Glendora, CA), 0.016 × 0.022-inch, were bent by cold-hardening bending and DERHT methods into 1-mm, 2-mm, or 3-mm offset for a 3-point bending test, and at angles of 30°, 45°, or 60° to the horizontal plane for testing the change in transformation temperature (Af) measured by differential scanning calorimetry (DSC). The data were analysed using ANOVA followed by the Scheffe post-hoc test. Results The 3-point bending test results of the cold-hardening bending and DERHT methods were not significantly different between the 1-mm, 2-mm and 3-mm offset groups (95% CI: −0.05 to 0.97; P = 0.082, 95% CI: −0.65 to 0.74; P = 0.983 and 95% CI: −0.61 to 0.98; P = 0.813, respectively). Increasing the offset resulted in a significantly decreased force in the 3-point bending test (P Conclusions NiTi archwire shape can be modified by using both cold-hardening and DERHT bending methods, because the mechanical properties and Af temperature are not affected. However, the bending distance has an effect on the mechanical properties.

Bipolar vessel sealing (BVS) is an advanced hemostasis approach applied in surgical operations. However, lateral thermal damage to adjacent nerves or tissue has remained an issue needing further investigations, because the thermal damage might increase the likelihood of the BVS surgical complications. Study on the tissue thermal properties help to reduce tissue lateral thermal damage, it is because understanding the thermal transmission mechanisms of BVS depends on achieving accurate values for tissue thermal conductivity (TC) and thermal diffusivity (TD), and accurately predicting their evolution. Therefore, in this work, experiments are conducted on the effect of the water content, compression ratio, and temperature on the TC/TD of a bovine femoral artery model in vitro using the step-temperature method and one-factor analysis of the TC/TD variance. The experimental results show that the TC/TD is significantly dependent on these factors. The TC/TD have a positive correlation with the temperature and water content and a negative correlation with the compression ratio. Regression equations are established for the TC/TD versus temperature (14 °C to 60 °C) and compression ratio from no compression (0%) to 90%. The study results could provide key parameters for vessel thermal transmission analysis on the sealing strength and thermal diagnosis of BVS.

This in vitro study compared the performance of the XP-endo Shaper (XP; FKG, La Chaux-de-Fonds, Switzerland) in curved canals when used with a higher speed (3000 rpm) without a glide path with the manufacturer's protocol.Twenty extracted mandibular molars with separate mesial curved canals were matched to obtain 2 standardized groups (n = 20). For the XP 1000 group, a glide path up to a size 15 hand file was performed followed by rotary instrumentation with the XP shaper at 1000 rpm, following the manufacturer's recommendations. For the canals in the XP 3000 group, the file was rotated at 3000 rpm after only negotiation the canal with a size 8 hand file (patency file). The operating time and the number of strokes taken to reach the working length (WL) and fit a 30/.04 gutta-percha cone to the WL were recorded. The shaping abilities were evaluated by micro-computed tomographic imaging and file deformation by scanning electron microscopy. Data were analyzed using analysis of variance and chi-square tests at a 5% significance level.The XP 3000 group required less time and strokes to reach the WL (P.05) and resulted in a higher percentage of adequate cone fit (P.05). No difference was found between groups regarding the micro-CT parameters, except for the taper, which was larger in the XP 3000 group in the apical and middle thirds (P.05). No difference was found regarding file deformation between the 2 groups.The suggested protocol for the use of the XP (3000 rpm without a glide path) appears to be more efficient than the manufacturer's recommended protocol to prepare curved canals in vitro.