RESUMEN
Background The decision-making of the most appropriate provisional restoration option in single-tooth implant practice is complex under multi-criteria conditions. The aim of our study is to conduct a case study on the determination of the appropriate provisional treatment option to be used in a single-tooth dental implant interim period after placement with the help of an entropy-based additive ratio assessment. Methodology Eight important criteria for fulfilling this purpose have been extracted from the literature search: "esthetic potential," "patient comfort," "treatment time," "laboratory cost," "occlusal clearance," "ease of removal," "durability," and "ease of modification." Provisional treatment alternatives are "removable partial denture," "vacuum-formed appliances," "bonded extracted tooth or denture," "metal or fiber-reinforced resin-bonded fixed partial denture," "wire-retained resin-bonded fixed partial denture," "acrylic resin provisional fixed partial denture," and "implant-supported fixed provisional restoration." It has been examined which of these alternatives is most appropriate in terms of both reported specifications and artificially generated dominance scenarios. The scenarios employed are S0 (criteria are equal-weighted), S1 (the criterion is tri-fold dominant), and S2 (the criterion is two-fold dominant). Results "Patient comfort" was the most important criterion (wj = 0.19). The remaining criteria were ranked as "modifications," "treatment time," "durability," "esthetic potential," "laboratory cost," "occlusal clearance," and "ease of removal." The "implant-supported fixed provisional restoration" treatment option had the maximum degree of utility in the S0 (Ki = 0.782) and S2 (Ki = 0.80) categories. If "treatment time" or "occlusal clearance" is the dominant variable, "vacuum-formed appliances" had the highest degree of utility (Ki = 0.69) in S1. Conclusions According to the rankings and scenarios created utilizing entropy-based additive ratio assessment methods, the "implant-supported fixed provisional restoration" is the appropriate provisional option for a single-tooth implant treatment. If "treatment time" or "occlusal clearance" is an absolute criterion, the "vacuum-formed provisional appliance" will replace the appropriate option.
RESUMEN
BACKGROUND: This study aimed to evaluate the removal efficiency of different capping materials used in pulp revascularization (PR) in a failure scenario. METHODS: The apices of freshly extracted 30 maxillary incisors were cut to mimic the immature teeth; then, root canals were shaped up to #6 Peeso reamers. The regeneration steps of the American Association of Endodontists (AAE) were followed to simulate PR treatment in vitro. The canals were dressed with the Ciprofloxacin and Metronidazole medicament mixture for 2 weeks. Then capping material groups were created: BioDentine (BD), ProRootMTA (PMTA), and RetroMTA (RMTA) (n = 10). The sealed specimens were stored for 2 weeks at 37 ºC in phosphate-buffered saline then the samples were examined by micro-computed tomography (µ-CT) analysis. Set capping materials were retrieved using a specific cement removal kit by a single blind operator. The residue materials were examined again by µCT. Kruskal-Wallis and Mann-Whitney U tests sought the significance for residue volumes. One-way ANOVA and Tukey post hoc tests with the Bonferroni corrections sought significance for the duration (p = 0.05). RESULTS: In the first examined µCT data, the mean (SD) capping material volumes of the PMTA, BD, and RMTA were 6.447 µm3 (1.086), 8.771 µm3 (0.491), and 8.114 µm3 (2.447), respectively. In the last examined µCT data, the median (IQR) residual volumes of the PMTA, BD, and RMTA were 0.051 µm3 (0.1), 0.313 µm3 (0.5), and 0.124 µm3 (0.1), respectively. A significant difference was found between BD and PMTA in the residual volumes (p < 0.05). The mean (SD) durations of the retrieving procedures of PMTA, BD, and RMTA were 19.83 min (2.34), 19.24 (3.60), and 22.04 (1.68), respectively (p = 0.063). CONCLUSIONS: Within the limitations of the presented study, it was concluded that the capping materials were largely removed from the root canals using a non-invasive approach. Nevertheless, this duration of the retrieving could be described as long.
Asunto(s)
Ciprofloxacina , Pulpa Dental , Humanos , Método Simple Ciego , Microtomografía por Rayos X , Análisis de Varianza , Ciprofloxacina/uso terapéuticoRESUMEN
BACKGROUND: To analyse the changes in surface and nickel ion release characteristics of fractured root canal shaping instruments in a simulated body fluid environment. METHODS: A total of 54 new instruments were studied. The instrument groups consisted of five different NiTi alloys and a stainless-steel alloy. To standardize instrument fracture, a torsional type of failure was created on each instrument. The fractured specimens of each instrument group were randomly divided into three static immersion subgroups of 1 h, 7-day, and 30-day (n = 3). Simulated body fluid (SBF) was prepared to mimic human blood plasma by Kokubo&Takadama protocol for ex situ static immersions at 37ºC. The surfaces were examined via scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. To determine the quantitative ion release, the retrieved SBFs were analyzed using inductively coupled plasma mass spectrometry. Two-way ANOVA and Tukey post hoc tests sought the statistical significance of the nickel ion values(p < 0.05). RESULTS: In 1 h of immersion, the newly formed structures, exhibiting mostly oxygen signals, were widespread and evident on NiTi surfaces. In contrast, fewer structures were detected on the SS surface in that subgroup. In 7 days of immersion, a tendency for a decrease in the density of the new structures was revealed in NiTi groups. The oxygen signals on NiTi group surfaces significantly increased, contrary to their decrease in SS. Signals of sodium, chlorine, and calcium were detected, indicating salt precipitates in groups. In 30 days of immersion, salt precipitates continued to form. The Ni-ion release values in all instrument groups presented significant differences in comparison to the SBF control in all immersion periods(p < 0.001). No significant differences were observed in immersion time periods or instrument groups(p > 0.05). CONCLUSIONS: Within the limitations of the presented study, it was concluded that the fractured SS and NiTi root canal instruments release Ni ions in contact with body fluid. However, the Ni ion release values determined during the observation periods are lower than the critical toxic or allergic thresholds defined for the human body. This was due to the ionic dissolution cycle reaching a stable state from 1-hour to 30-day exposure to the body fluid of fractured instruments.
Asunto(s)
Níquel , Tratamiento del Conducto Radicular , Humanos , Níquel/química , Aleaciones , Aleaciones Dentales/química , Titanio/química , Iones , Preparación del Conducto Radicular , Propiedades de Superficie , Ensayo de Materiales , Diseño de EquipoRESUMEN
INTRODUCTION: To demonstrate the unknown kinematics of complex adaptive motion with respect to disclosed values, the aim of this study was (1) to analyze the adaptive motion and (2) to compare the effects of constant torque values on kinematics. METHODS: A new endodontic motor (Aseptico AEU-28SYB Elements; SybronEndo, Orange, CA) and 8:1 contra-angle handpiece were used for analysis. A pilot test was conducted for synchronizing the external experimental stress on the shaft of the target object and the built-in torque sensor of the motor source. A load setup was developed by attaching universal precision weights to the shaft of the of the target object. The groups were adaptive motion with no load (TFA-0), adaptive motion with a 100-gcm constant load (TFA-100), and adaptive motion with a 200-gcm constant load (TFA-200). The peak-to-peak-based phase identification method was used to analyze the kinematics. Student t and Mann-Whitney U tests were used where applicable (α = 0.05). RESULTS: A noteworthy observation was the inconsistent kinematics of TFA-100 compared with the kinematics of TFA-0 and TFA-200. TFA-100 presented mixed-phased kinematics, which consisted of both a quaternary phase (n = 33) similar to that of TFA-200 and a dual phase (n = 17) similar to that of TFA-0. The sequence of these quaternary and dual phases of TFA-100 was arbitrarily changing. The kinematic parameters of dual-phase intermittent motion of TFA-0 and TFA-100 and quaternary-phase reciprocating motion of TFA-100 and TFA-200 revealed significant differences (P < .05). CONCLUSIONS: The main conclusions of the present study are the kinematics of adaptive motion was demonstrated, and the 100-gcm load is not sufficient for predictable and constant operation in the reciprocating mode.
Asunto(s)
Preparación del Conducto Radicular , Fenómenos Biomecánicos , Diseño de Equipo , Humanos , Movimiento (Física) , Rotación , TorqueRESUMEN
OBJECTIVES: The aims of this study are (i) to propose specific selection criteria related to NiTi instruments for dental practitioners and (ii) to objectively assess the NiTi instruments. MATERIALS AND METHODS: The steps of the methodology are as follows: Step 1: "Delphi method" was employed to reach a consensus on criteria defined according to the literature review and a group of panelists. Step 2: "Smart pairwise comparisons" were employed to rank the proposed criteria. Step 3: "Borda voting" was employed to determine the weights of the proposed criteria. Step 4: To determine assessment scores, "Simple Additive Weighting" was employed. Step 5: Reliability and validity checks were made by "simulation." RESULTS: Specific criteria classified under dimensions were proposed and weighted for the NiTi instrument assessment. In this context, an assessment model was proposed and validated. CONCLUSIONS: The proposed assessment model for NiTi instruments could aid to make the decision-making process as systematic, transparent, and reproducible as possible not only for dental practitioners but also for healthcare professionals. Also, this proposed model can represent a reference framework for further MCDM studies which can rank or classify materials in medical science. CLINICAL RELEVANCE: The model proposed in this study can be used to aid decision-making in clinical practice by means assessing the NiTi instrumentation system alternatives for practitioners.
Asunto(s)
Instrumentos Dentales , Níquel , Aleaciones Dentales , Materiales Dentales , Odontólogos , Diseño de Equipo , Humanos , Ensayo de Materiales , Rol Profesional , Reproducibilidad de los Resultados , Preparación del Conducto Radicular , TitanioRESUMEN
To investigate intrinsic physicochemical properties and interactions of three different calcium hydroxide-based medications via means of different analytical methods. Two-commercial premixed medications: TempCanal(TCmx) and ProCalR(PCmx) and powder-form ProCal(PCpw) with glycerin were used. Vibrational modes were analyzed using Raman spectroscopy. Spectral mapping of samples was carried out using characteristic vibrational modes of calcium hydroxide and barium sulfate. Crystalline and amorphous phases were studied with X-rays powder diffraction analysis. Topographic features were examined by scanning electron microscope examination and quantitative analysis was determined using energy-dispersive X-ray spectroscopy analysis. Strong OH stretch of in Raman spectra were observed at 3,697 and 3,615 cm-1 for TCmx and reference, respectively. However, OH mode was not observed for PCmx and PCpw. Moreover, some peaks in the fingerprint areas of TCmx and PCpw overlapped with each other. The characteristic vibration bands of barium sulfate and calcium hydroxide were observed in all samples, and no new peak was observed in the Raman spectra of samples. Calcium hydroxide-based medications were seen as differed in their chemical composition. No new crystalline or amorphous phase peak was observed. Only calcium hydroxide and barium sulfate were matched in X-rays powder-diffraction analysis. Energy-dispersive X-ray spectroscopy analysis showed that amount of Ba and S elements in the PCpw were lower than TCmx and PCmx whereas, for Ca in the PCpw was higher than TCmx and PCmx. The present study revealed the structural difference among different forms of calcium hydroxide-based medications. The vehicle and substrates of the tested medications altered the physicochemical properties of the compound via electrostatic interactions.
RESUMEN
To evaluate monotonic torsional resistance and fatigue resistance of novel SCOPE RS instruments and to compare ROTATE, Hyflex CM, OneCurve, and ProTaper Next instruments as a counterpart. The instrument groups were as follows: SCOPE RS; ROTATE; HyflexCM; OneCurve; ProTaperNext. The cyclic fatigue resistance of unused instruments was tested at both room and body temperatures (n = 10). The time to fracture, the mean number of cycles until failure, and the length of the fractured fragments were analyzed. The monotonic torsional resistance of new instruments was measured in accordingly American National Standards/American Dental Association No. 28 and International Organization for Standardization 3630-1:2008 specifications (n = 10). The maximum torque and angular deflection at break were recorded. The fractographic examination was performed by scanning electron microscope. Energy-dispersive X-ray spectroscopy was used to investigate the microstructure of NiTi instruments. One-way ANOVA with Games-Howell Post Hoc multiple comparisons tests were used (p < .05). The ROTATE had superior cyclic fatigue resistance than other groups in both temperature conditions (p < .01). However, it exhibited lower torsional resistance than SCOPE RS (p < .01). SCOPE RS had superior torsional resistance than other groups (p < .01). Micrographs revealed typical features of fatigue behaviors in all groups. Weight percentages of the Ni and Ti revealed similarity for all instruments. The novel SCOPE RS instruments presented superior monotonic torsional resistance but failed to show any improvement in the cyclic fatigue resistance compared with its counterparts, ROTATE, HyflexCM, and OneCurve.
RESUMEN
The aim of this article was to investigate the unknown radiopacity performances of OrthoMTA and RetroMTA via means of a contemporary image analyzing methods and energy dispersive X-ray spectroscopy. Three commercial hydraulic calcium silicate-based cements and a calcium hydroxide-based paste were used. Pure-grade zirconium oxide, bismuth oxide, zinc oxide, barium sulfate, and calcium hydroxide were as references. An energy-dispersive X-ray spectroscopy instrument was used for the elemental analysis. Radiographic image data was obtained according to the International Organization for Standardization 6876-2012 specifications. The region of interest was determined for each specimen. Mean (±SD) grey values of the X-ray image data was measured with an image analyzing software. The calibration curve was created by curve-plotting software and the mean grey-values were matched versus Al values (mm Al). Data were analyzed with one-way ANOVA followed by Tukey's multiple comparison test. Spectroscopic characterization of the commercial materials was shown with assigned Carbon, oxygen, aluminum, silicon, calcium, zinc, zirconium, barium, tungsten, bismuth, and sulfur elements. The major radiopacifier/s of OrthoMTA is Bi, of RetroMTA is Zr, of BioDentine are Ba and Zr, and of ProCal is Ba. The radiopacity values of all commercial materials are significantly different (p < .05). The rank of the radiopacity values: RetroMTA (3.36 ± 0.29mmAl) > OrthoMTA (2.56 ± 0.19mmAl) > BioDentine (2.02 ± 0.12mmAl) > ProCal (1.46 ± 0.60mmAl). The study reported that the radiopacity values and spectral characterization of RetroMTA and OrthoMTA cements. The pixel-based and reproducible method could be used universally to the quantification of the radiodensity of digitally collected X-ray data.
RESUMEN
The purpose of the study was to evaluate the smear layer removal efficacy of novel Saver® irrigating solution including 5% EDTA and to compare the 17% EDTA as the most used counterpart. Forty-four single-rooted teeth were divided into four groups, were instrumented, and irrigated. The smear treatment groups were as follows: sterile distilled water; 5.25% sodium hypochlorite; Saver®; 17% EDTA. The root samples were blinded. The micrographic images of root samples were collected by scanning electron microscope. The percentages of open dentin tubules were quantified using an image analysis software on micrographs. Two-way ANOVA followed by Tukey's multiple comparisons was used (p < .05). The 17% EDTA showed the highest percentages of open dentin tubules than the other treatments (p < .01). The mean percentages of open dentin tubules of 17% EDTA revealed statistically highly significant differences than Saver® treatment in all root regions (p < .01). Dentin tubules were covered by dense smear layer in distilled water irrigation whereas, the tubular pattern of dentin structure was not observed in hypochlorite irrigation. The commercial Saver® product presented to be less cleaning property on the smear layer than 17% EDTA and failed to show any improvement in the removal of smear layer compared with its tested counterpart.
RESUMEN
Objective: The aim of this in vitro study was to investigate the possible interactions between photon-induced photoacoustic streaming (PIPS™)-activated oxidizing agents and 2% chlorhexidine digluconate. Background data: There is no information about the safety of laser-activated oxidizing agents in combination usage with chlorhexidine gluconate. Materials and methods: Groups were designed as follows G1: 98% para-chloroaniline (PCA); G2: 2% chlorhexidine (CHX); G3: 5.25% sodium hypochlorite (NaOCl) +2% CHX; G4: 5.25% NaOCl (30 sec PIPS activated) +2% CHX; G5: 5.25% NaOCl (60 sec PIPS activated) +2% CHX; G6: 3.5% chlorine dioxide (ClO2) + 2% CHX; G7: 3.5% (ClO2) (30 sec PIPS activated) +2% CHX; G8: 3.5% (ClO2) (60 sec PIPS activated) +2% CHX. The laser-irrigation protocol was performed with an erbium:yttrium-aluminum-garnet laser with a wavelength of 2940 nm equipped with a 140 mm long endodontic fiber tip (PIPS) using 10 mJ at 15 Hz (0.15 W), per pulse operating outputs. Groups were analyzed with proton nuclear magnetic resonance spectroscopy, using PCA as an internal standard. Results: No free PCA was formed in any groups of mixtures or after PIPS activation. Conclusions: Mixing of 3.5% ClO2 and 2% CHX does not form bulky precipitates, unlike the mixture NaOCl + CHX. PIPS activation does not cause changes in reactions of oxidizing agents.
Asunto(s)
Antiinfecciosos Locales/efectos de la radiación , Clorhexidina/análogos & derivados , Terapia por Luz de Baja Intensidad , Oxidantes/efectos de la radiación , Técnicas Fotoacústicas , Irrigantes del Conducto Radicular/efectos de la radiación , Compuestos de Anilina/efectos de la radiación , Clorhexidina/efectos de la radiación , Láseres de Estado Sólido , Espectroscopía de Protones por Resonancia Magnética , Preparación del Conducto Radicular , Hipoclorito de Sodio/efectos de la radiaciónRESUMEN
The aim was to evaluate the effects of different irrigation protocols on the bonding ability of fiber posts on root canal dentin through push-out test and the dentin tubule penetration of luting cement by confocal laser scanning microscope (CLSM). Forty-eight single-rooted premolars were divided into six groups (n=8) based on post space irrigation protocols: Saline 0.85%; Etidronate 18% (HEBP); EDTA 17%; NaOCl 5.25%+EDTA 17%; NaOCl 2.5%/HEBP 9% combination; SmearOFF. Two specimens per group were assessed with CLSM. The push-out test and the failure analysis were performed. Whilst EDTA had the highest bond strength at the coronal and middle thirds, it was not statistically significant compared to saline, HEBP, and NaOCl/HEBP at the middle third (p>0.05). Cement/dentin adhesive failures were predominant (41.9%) and the intratubular fluorescence intensity was significant among the groups (p<0.05). EDTA resulted in highest bond strength values and dentinal penetration.
Asunto(s)
Recubrimiento Dental Adhesivo , Técnica de Perno Muñón , Cavidad Pulpar , Dentina , Ácido Edético , Ácido Etidrónico , Cementos de Resina , Irrigantes del Conducto Radicular , Preparación del Conducto Radicular , Hipoclorito de SodioRESUMEN
OBJECTIVE: The aim of the study was to evaluate the effect of different dry-polishing regimens on the intrapulpal temperature assessed using a pulpal blood microcirculation model. MATERIALS AND METHODS: Eighty extracted human mandibular premolar teeth were used. Standardized class V cavity preparations were performed and were then restored. Teeth were divided into four main groups (n = 20): Fine polishing disc (SSF; 3M Sof-Lex, 3M ESPE, Minnesota); Super-fine polishing disc (SSS; 3M Sof-Lex); Spiral finishing wheel (SSW; 3M Sof-Lex); Enhance PoGo-One step diamond micro-polisher cup (EPO; Dentsply Sirona, Inc, Delaware). The main groups were divided: the low-load pressure (0.4N) and the high-load pressure (0.8N). The average change in intrachamber temperatures (Δt), from initial to highest, were measured. RESULTS: The highest temperature increase was recorded in SSF08 (9.55°C). The lowest value was recorded in EPO04 (1.9°C). SSS08, SSW08, and EPO08 demonstrated significantly higher Δt values than the low-load mode in SSS04, SSW04, and EPO04, respectively (P < .0001). CONCLUSIONS: Temperature was the least affected by the diamond cup in both pressure modes, and it was also less affected by the spiral finishing wheel in the low-load mode than in the high-load mode. Fine and super-fine discs had the greatest effect on intrachamber temperatures. CLINICAL SIGNIFICANCE: The present study suggests intrachamber temperature can rise among different dry-polishing regimes. Dental practitioners should pay attention to dry-polishing regimens and pressures for reducing heat-related dental problems.
Asunto(s)
Resinas Compuestas , Pulido Dental , Humanos , Ensayo de Materiales , Microcirculación , Propiedades de Superficie , TemperaturaRESUMEN
OBJECTIVE: To evaluate the influence of saliva contamination and cleaning procedures on shear bond strength (SBS) of a self-adhesive resin cement (SAC) to zirconia surfaces. MATERIALS AND METHODS: A total of 160 sandblasted zirconia blocks were randomly divided into eight groups as follows: No saliva contamination, no cleansing (NC-NC); contamination with saliva, no cleansing (SC-NC); no saliva contamination, cleansing with a zirconia primer (ZP; Z-Bond, Danville Materials, Inc., S. Ramon, California) (NC-ZP); contamination with saliva, cleansing with ZP (SC-ZP); no saliva contamination, cleansing with hydrofluoric acid (HF; Ultradent Porcelain Etch; Ultradent Products, South Jordan, Utah) followed by cleansing with ZP (NC-HF-ZP); contamination with saliva, cleansing with HF followed by cleansing with ZP (SC-HF-ZP); cleansing with ZP, contamination with saliva, cleansing with ZP (ZP-SC-ZP); application of ZP, contamination with saliva, cleansing with HF followed by cleansing with ZP (ZP-SC-HF-ZP). Cylindrical resin composite blocks were luted to the zirconia surfaces with SAC (Clearfil SA Cement Automix, Kuraray, Inc., Tokyo, Japan). Specimens were subjected to shear forces at a cross-head speed of 0.5 mm/min. Data were analyzed with Analysis of Variance and Tukey tests (α = 0.05). RESULTS: The bond strength values to zirconia were significantly influenced by saliva contamination (P < .05). The SC-NC group showed the lowest bond strength values (5.6 ± 1.4 MPa; P < .05). All cleansing or pretreatment agents improved the bond strengths when compared to noncleansing groups, NC-NC and SC-NC. CONCLUSION: In situations where saliva contamination is deemed unavoidable, application of ZP after try-in of the zirconia restoration could be beneficial for the accurate cementation. CLINICAL SIGNIFICANCE: During try-in sessions of fixed dental prostheses, zirconia ceramic restoration may come into contact with saliva and surfaces should be cleansed to obtain an optimal surface for adhesion. Application of zirconia primer to the sandblasted zirconia surface is recommended whether the surface is contaminated with saliva or not.
Asunto(s)
Recubrimiento Dental Adhesivo , Análisis del Estrés Dental , Japón , Ensayo de Materiales , Cementos de Resina , Saliva , Propiedades de Superficie , CirconioRESUMEN
BACKGROUND: Mixing sodium hypochlorite (NaOCl) with chlorhexidine (CHX) forms a brown precipitate. QMix-2in1 (QMix) was introduced as a final irrigant. Manufacturer recommends interim flushing with saline between the application of NaOCl and QMix to prevent formation of precipitation. This study assessed whether para-chloroaniline (PCA) is formed after mixing NaOCl with QMix. METHODS: Commercially available, 5.25% NaOCl solution, 2% CHX, QMix, 15% ethylenediaminetetraacetic acid (EDTA) and 98% PCA in powder form were used. Groups were prepared at room temperature. Group 1, 98% PCA in powder form; Group 2, 2% chlorhexidine (CHX); Group 3, QMix; Group 4, 5.25% sodium hypochlorite (NaOCl) mixed with QMix; Group 5, 5.25% NaOCl mixed with CHX; Group 6, 15% EDTA mixed with CHX. The precipitates were extracted and analysed with Proton Nuclear Magnetic Resonance (1H-NMR) and Infrared (IR) Spectroscopy, using PCA as an internal standard. RESULTS: No PCA was found in any of the irrigant-mixture groups tested. CONCLUSIONS: This study used the interpretation of spectral results for the amino signals of precipitate formed after mixing QMix with 5.25% NaOCl using different nondestructive analysis methods, with PCA as an internal standard (control). We conclude that mixing QMix or 2%CHX with 5.25% NaOCl does not yield free PCA.
Asunto(s)
Biguanidas/química , Espectroscopía de Resonancia Magnética , Polímeros/química , Hipoclorito de Sodio/química , Espectrofotometría Infrarroja , Cromatografía de Gases y Espectrometría de Masas , HumanosRESUMEN
This study evaluated the effect of simulated chewing forces on the flexural strength of fiber reinforced posts (FRPs). Four different brands of FRPs were selected as main group for the study: RelyX Fiber Post (RX), IceLight (ICE), Unicore Posts (UC), FlouroPost (FP). Ten posts in each main group didn't receive any aging process and tested as baseline (BL), other ten posts were subjected to simulated chewing forces/mechanical aging (MA) as follows: Post spaces were prepared in acrylic with drill. Depth of preparation was adjusted to leave 4-mm coronal part of posts protruding from canals. Coronal parts were incrementally restored with resin-composite (Clearfil Majesty Posterior A2, Kuraray, Osaka, Japan). Prepared samples were subjected to chewing cycles in a chewing simulator (Chewing Simulator CS-4, Mechatronik, Germany). Flexural strengths of all groups were measured with three-point bending test. Data were analyzed by two-way ANOVA and Tukey's test (α = 0.05). After MA, flexural strengths of all posts were significantly decreased when compared with BL for all FRPs tested (p < 0.05). At BL, highest flexural strength values were obtained for ICE. After MA, similar to BL, highest flexural strength values were obtained for ICE. Only RX showed statistically significant difference when compared with ICE (p < 0.05). UC and FP showed similar flexural strength values with ICE (p > 0.05). It may be concluded that chewing forces on post-core systems may reduce the flexural strengths of FRPs.
Asunto(s)
Cementos Dentales , Materiales Dentales , Diseño de Prótesis Dental , Masticación , Adhesividad , Resinas Compuestas , Análisis del Estrés Dental , Elasticidad , Humanos , Ensayo de Materiales , Docilidad , Estrés Mecánico , Propiedades de SuperficieRESUMEN
This study investigated the effect of rubbing force magnitude on dentin bond strengths of multi-mode adhesives applied in self-etch mode. Seventy-two extracted human molar teeth were used. Two different universal adhesives Single Bond Universal (SB) and Clearfil Universal (CL) were applied onto dentin surfaces in three different modes: without rubbing (NR), rubbing with 40 gf (gram-force) (40) or 80 gf (80) load. Teeth were restored with a resin composite. Half of the specimens were subject to thermal aging (10,000 cycles). Microtensile bond strength was measured and data were statistically analyzed with two-way analysis of variance and Tukey's test (α=0.05). Baseline bond strength values for CL adhesive were improved by rubbing (40 and 80 gf) as compared to no rubbing (p<0.05). Rubbing did not significantly improve bond strength values for SB, regardless of aging (p>0.05). Rubbing improves bonding performance of some universal adhesives to dentin when applied in self-etch mode.
Asunto(s)
Grabado Ácido Dental , Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios/química , Bisfenol A Glicidil Metacrilato , Humanos , Técnicas In Vitro , Ensayo de Materiales , Diente Molar , Cementos de Resina , Estrés Mecánico , Propiedades de Superficie , Temperatura , Resistencia a la TracciónRESUMEN
[This corrects the article DOI: 10.1371/journal.pone.0183895.].