共查询到20条相似文献，搜索用时 31 毫秒
1.
Bruna M.B. de Oliveira Izabelle E. Agostini Mauro L. Baesso Rafael Menezes-Silva Ana Flávia S. Borges Maria Fidela L. Navarro John W. Nicholson Sharanbir K. Sidhu Renata C. Pascotto 《Dental materials》2019,35(3):450-456
Objective
To evaluate the influence of external energy sources on the dynamic setting process of glass-ionomer restorative materials.Methods
Eighteen brands of GIC were studied: Bioglass R (Biodinâmica; G1), Chemfil Rock (Dentsply; G2), Equia Forte (GC; G3), Gold Label 2 (GC; G4), Gold Label 9 (GC; G5), Glass Ionomer Cement Type II — (Shofu; G6), Ionglass R (Maquira; G7), Ion Z (FGM; G8), Ionomaster (Wilcos; G9), Ionofil Plus (Voco; G10), Ionostar Plus (Voco; G11), Ketac Molar easymix (3M ESPE; G12), Magic Glass R (Vigodent; G13), Maxxion R (FGM; G14), Riva Self Cure (SDI; G15), Vidrion R (SS White; G16), Vitro Fil R (Nova DFL; G17) and Vitro Molar (Nova DFL; G18). LED, halogen light or ultrasound (n = 20 for each set) applied for 30 s was used to activate setting, and a control group of each material was allowed to set without activation. Samples were analyzed by FTIR spectroscopy using the ratio of intensities of bands at 1637 cm?1 (carboxylate) and 1720 cm?1 (carbonyl) as a function of time. Means and standard deviations were subjected to ANOVA and Tukey tests (p < 0.05).Results
All three activation modes significantly reduced the time at which the carboxylate content became stable in G2, G4, G5, G6, G8, G10, G14, G16, G17 and G18. By contrast, in G1, G7, G12 and G15 no activation source had any significant effect (p > 0.05).Significance
External activation sources, namely LED, halogen light and ultrasound, typically but not always increase the setting rate of restorative GICs. 相似文献2.
Akihisa Kodaira Hiroyasu Koizumi Hiroshi Nogawa Kentaro Okamura Mitsuo Nakamura Takayuki Yoneyama 《Journal of prosthodontic research》2019,63(2):145-149
Purpose
The aim of this study was to evaluate the shear bond strength and durability of MMA-TBB resin to human enamel applied a self-etching primer with phosphoric acid etching.Methods
A self-etching primer (Teeth primer, TP) containing 4-methacryloyloxyethyl trimellitate anhydride (4-META) and sodium sulfite and two etchants having different phosphoric acid concentrations (K-etchant gel, KE, 35–45%: Red gel, RG, 20–25%) were used as treatment agent, and MMA-TBB resin was used as luting agent. Enamel surfaces were treated with six methods which were as follow: KE, RG, TP, KE + TP, and RG + TP. After enamel specimens were bonded with MMA-TBB resin and stored in distilled water for 24 h, the shear bond strength test was done at 0 thermocycling or 20,000 thermocycling. These results were statistically verified with Steel-Dwass multiple comparisons and Man–Whitney U test.Results
The shear bond strength of TP group, KE + TP group, and RG + TP group were significantly higher than KE group and RG group in pre-thermocycling. KE + TP group and RG + TP group were significantly higher than other groups in post-thermocycling.Conclusions
Applying TP with phosphoric acid etching can increased shear bond durability despite difference of phosphoric acid concentrations (35–45% or 20–25%). 相似文献3.
Tomohide Kondo Futoshi Komine Junichi Honda Hiroki Takata Yuta Moriya 《Journal of prosthodontic research》2019,63(2):140-144
Purpose
To determine the effect of veneering material and framework design on fracture loads of implant-supported zirconia molar fixed dental prostheses (FDPs).Methods
Sixty-six zirconia FDPs were manufactured onto two implants and classified as uniform thickness (UT) or anatomic design (AD). These framework design groups were then further divided into three subgroups (n = 11): feldspathic porcelain-veneered zirconia FDPs (PVZ), indirect composite-veneered zirconia FDPs (IVZ), and metal–ceramic FDPs (MC). The FDPs were luted on the implant abutments and underwent fracture load testing. Significant differences were assessed by the Kruskal–Wallis test and Mann–Whitney U-test (α = 0.05).Results
For UT group, median fracture load was significantly higher for the IVZ (1.87 kN) and MC (1.90 kN) specimens than for the PVZ specimens (1.38 kN) (p < 0.05). In the AD group, the IVZ specimens had the highest median fracture load (4.10 kN) of the three groups tested. The AD group exhibited higher median fracture loads than the UT group in all subgroups.Conclusions
Indirect composite appears to be a useful alternative to feldspathic porcelain as the layering material for implant-supported zirconia FDPs. The AD group had higher fracture loads than UT group. In addition, implant-supported indirect composite-veneered zirconia-based FDPs appear to be clinically feasible. 相似文献4.
Jin Feng Lei Cheng Xuedong Zhou Hockin H.K. Xu Michael D. Weir Qian Li Matthias Hannig Stefan Rupf 《Dental materials》2019,35(3):434-443
Objectives
The aims of this study were to investigate the effects of water aging for up to 6 months on the mechanical and anti-biofilm properties of a novel antibacterial glass ionomer cement (GIC) containing dimethylaminododecyl methacrylate (DMADDM).Methods
GIC specimens (n = 180) which contained DMADDM (0 wt.%, 1.1 wt.% or 2.2 wt.%) were prepared. The mechanical properties surface roughness, microhardness and the surface charge density of ammonium groups were measured before and after water aging for 3 and 6 months at 37 °C. Further six months aged specimens (n = 216) were worn by 6 volunteers in their oral cavities for 24 h and 72 h. Biofilm formation was analyzed and rated by fluorescence microscopy (FM) and by scanning electron microscopy (SEM). Biofilm viability was analyzed by FM.Results
Water aging did not show any adverse effects on the surface roughness and hardness of the material. The surface charge density of the GIC samples containing DMADDM decreased due to the aging procedure, however, was still higher than that of the GIC without DMADDM. In situ biofilm formation was significantly reduced after 24 h on DMADDM containing GIC (p < 0.05). FM results showed a higher ratio of red/green fluorescence on GIC-DMADDM samples.Significance
Incorporating DMADDM into GIC affected the material properties in a tolerable manner even after 6 months of storage in water. The new GIC is a promising material to affect the biofilm formation on the surface of restorations. 相似文献5.
Vitor Guarçoni de Paula Gerson Bonfante Fabio C. Lorenzoni Paulo G. Coelho Leonardo Rigoldi Bonjardim Vinicius P. Fardin Estevam A. Bonfante 《Dental materials》2019,35(3):511-522
Objective
To evaluate the probability of survival of monolithic and porcelain veneered lithium disilicate crowns comprised by a conventional or modified core when loaded on marginal ridges.Methods
Lithium disilicate molar crowns (n = 30) were fabricated to be tested at mesial and distal marginal ridges and were divided as follows: (1) bilayered crowns with even-thickness 0.5 mm framework (Bi-EV); (2) bilayered crowns with modified core design (Bi-M-lingual collar connected to proximal struts), and: (3) monolithic crowns (MON). After adhesively cemented onto composite-resin prepared replicas, mesial and distal marginal ridges of each crown (n = 20) were individually cyclic loaded in water (30–300 N) with a ceramic indenter at 2 Hz until fracture. The 2-parameter Weibull was used to calculate the probability of survival (reliability) (90% 2-sided confidence bounds) at 1, 2, and 3 million cycles and mean life.Results
The reliability at 1 and 2 million cycles was significantly higher for MON (47% and 19%) compared to Bi-EV (20% and 4%) and Bi-M (17% and 2%). No statistical difference was found between bilayered groups. Only the MON group presented crown survival (7%) at 3 million cycles. The mean life was highest for MON (1.73E + 06), lowest for Bi-M (573,384) and intermediate for Bi-E (619,774). Fractographic analysis showed that the fracture originated at the occlusal surface. The highest reliability was found for MON crowns. The modified framework design did not improve the fatigue life of crowns.Significance
Monolithic lithium disilicate crowns presented higher probability of survival and mean life than bilayered crowns with modified framework design when loaded at marginal ridges. 相似文献6.
Yuka Yasui Junko Tanaka Masaki Kakudo Masahiro Tanaka 《Journal of prosthodontic research》2019,63(2):210-215
Purpose
The relation between preference and the gaze for the test foods under unconsciousness using the eye-tracking system was investigated.Methods
Participants consisted of 37 healthy volunteers. Test foods were steamed rice 150 g, grilled salmon approximately 45 g and slice cooked squash 60 g, all of which were served on a tray. Foods forms were regular food, chopped food, and blended food. After attached to the eye tracker, participants watched the each dish arranged in front of them freely for 10 s. And they ate test foods freely within 10 min. The gazing point was measured for 10 s from the time when the food was ordered and just before the eating. Preference levels were interviewed. The number of gaze point fixations and the total gaze point fixation time of the viewpoint during 10 s just before eating were analyzed. The analysis items were (1) the total number of gaze point fixations (2) the total gaze point fixation time (3) the amount of food intake and (4) the preference level details.Results
For foods with higher preference levels, the number of gaze point fixations increased significantly and the total gaze point fixation time significantly increased. In both groups, maximum food intake was observed for food forms with a high preference level. Most of the participants’ selected regular foods as their most preferred food form among the food forms.Conclusions
The results suggested that subjects gazed at regular food which had high preference level. 相似文献7.
Arunee Laiteerapong Franz-Xaver Reichl Reinhard Hickel Christof Högg 《Dental materials》2019,35(3):444-449
Objective
To formulate novel glass ionomer cements (GICs) containing zirconia (nanoparticles (NPs) and micro-particles (MPs)) and investigate the genotoxic effect of their eluates on DNA double-strand breaks of human gingival fibroblasts (HGFs) in vitro using a γ-H2AX fluorescent assay.Methods
GIC (control, C), 10%ZrO2NPsGIC (T1) and 10%ZrO2MPsGIC (T2) were prepared per the manufacturer’s instructions (hand-mixed, P/L = 3.4:1 w/w%). Dulbecco’s modified Eagle’s medium (DMEM) was used as the culture medium for HGFs and for eluate preparation. Eluates were collected from all specimens (n = 5/g, 5 × 2 mm) after 24 h and used for XTT to obtain the EC50 using Graph Pad Prism4. A γ-H2AX immunofluorescence assay was performed to detect DSBs in HGFs. The mean foci per cells and percentage of free foci cells were statistically compared (one-way ANOVA with Tamhane’s post hoc and Chi-square respectively) (p < 0.05).Results
(1) EC50 ranged from 31 to 36%. 5% and 20% eluate concentrations were selected for the genotoxicity test. (2) Cells exposed to eluates from T1 had lower mean foci per cell than cells in T2 and C eluates (p < 0.05). Only cells in T1 at 5% had lower mean foci cell than medium (p < 0.05). (3) T1 and C at both concentration showed a higher, but not significant, percentage of free foci cells than negative control (medium). At 20% eluate concentration T2 had a lower percentage of free foci cells than C (p < 0.05).Significance
Nano-zirconia GIC and micro-zirconia GIC were formulated. GIC and both zirconia modified GICs had no genotoxic effect on HGFs in vitro. Further studies related to physical properties should be performed to determine the future clinical applications for these novel nanomaterials. 相似文献8.
Junji Iwata Masaki Asakura Tatsuhide Hayashi Shozo Tsuruta Miki Hori Yoshinori Nagase Akimichi Mieki Seiji Ban Tatsushi Kawai 《Journal of prosthodontic research》2019,63(2):221-226
Purpose
Immersion tests in purified water were conducted to evaluate the leaching behaviors of filler elements contained in computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin.Methods
Four commercial CAD/CAM resin composite blanks were tested: Shofu block HC 2 layer, Cerasmart, Katana Avencia block, and KZR-CAD HR Block 2. The specimens in the size of 10.0 × 12.0 × 2.0 mm were immersed in a 50-mL conical tube containing 40 mL of purified water, and then placed in a constant-temperature oven set at a temperature of 37, 60, 70, or 80° C and stored statically for 30 days. After storage, the concentrations of leached elements in the immersion solution were measured with an inductively coupled plasma atomic emission spectrometer. To characterize the surface of the specimen after the immersion test, secondary electron images were obtained.Results
The immersion test resulted in the leaching of Si, the main component, from all materials tested. Some materials were found to have leached high amount of Ba or Sr in addition to Si, and remarkable surface degradation was observed. The amount of leached elements increased with increased immersion temperatures.Conclusions
Filler elements in CAD/CAM composite resins used in this study leached into purified water. The leached elements and its quantities greatly differed among materials and depend on the types of the oxides composing the filler. The amounts of leached elements varied in a temperature-dependent manner. 相似文献9.
Hideta Nishimori Takashi Iida Hirona Kamiyama Mika Honda Manabu Masuda Antoon De Laat Osamu Komiyama 《Journal of prosthodontic research》2019,63(2):193-198
Purpose
To investigate the effect of sleep restriction on somatosensory sensitivity related to occlusion.Methods
Twelve healthy participants participated in an experimental voluntary total sleep restriction (SR) study. In a study design, they were invited to sleep as usual, normal sleep (NS) or to restrict their sleep for four nights. Following the SR night, participants were followed for 3 consecutive days including the 2 sleep nights. In NS experiment, all participants were instructed to maintain NS both nights. During all nights, actigraphy data were collected and total sleep time was estimated. On days before and after sleep conditions, all participants underwent measurements of tactile detection threshold (TDT), interocclusal detection threshold (IDT), perception of unpleasantness (POU), and the Epworth sleepiness scale (ESS).Results
As expected, total sleep time on the first night in SR experiment was significantly shorter than on the second night in SR experiment and on the first night in NS experiment (P < 0.05). ESS values on Day-2 following SR experiment were significantly higher than on Day-1 and Day-3 in SR experiment and Day-2 in NS experiment (P < 0.05). There were no significant differences in TDT and IDT between each day at each measurement point in both experiments. POU was significantly lower on Day-2 in SR experiment than on Day-1 and Day-3 in SR experiment and on Day-2 in NS experiment (P < 0.05).Conclusions
The present results suggest that SR affects to occlusal sensation related to POU. 相似文献10.
Ana Maria Estivalete Marchionatti Vinícius Felipe Wandscher Iana Lamadrid Aurélio César Dalmolin Bergoli Liliana Gressler May 《Dental materials》2019,35(4):e63-e73
Objective
To compare file-splitting multilayer (fused and cemented) with monolithic Y-TZP on the fatigue flexural strength and finite element analysis (FEA) stresses. Additionally, to verify the effect of the material under tension in multilayer Y-TZP.Methods
Disc-shaped (diameter: 14.4 mm; thickness: 1.4 mm) monolithic Y-TZP (IPS e.max ZirCAD — Ivoclar Vivadent) and trilayer specimens with Y-TZP framework (IPS e.max ZirCAD), intermediate layer of fusion ceramic (IPS e.max CAD Crystall./Connect) or resin cement (Multilink Automix) and lithium disilicate veneer (IPS e.max CAD) were divided into five groups (n = 20): monolithic Y-TZP (M), fused file-splitting with framework under tension (F-FT), cemented file-splitting with framework under tension (C-FT), fused file-splitting with veneer under tension (F-VT) and cemented file-splitting with veneer under tension (C-VT). Fatigue flexural strength was determined (piston-on-three ball) by the staircase approach (750,000 cycles; 20 Hz). Mean and confidence intervals (CI) were calculated. FEA was evaluated under the application of the experimental mean fatigue load.Results
The fatigue strength was statistically different for all groups. Means and CI (MPa) were: M — 405.92 (CI 397.58–414.26), F-FT — 377.73 (CI 374.59–380.88), C-FT — 346.54 (CI 340.62–352.46), F-VT — 154.79 (CI 151.86–157.72) and C-VT — 100.34 (CI 97.42–103.26). FEA tensile stresses were similar to the mean experimental values (up to ?10 MPa of variation), with the most discrepant calculated stresses for C-FT (?20 MPa higher than experimental result).Significance
Monolithic specimens showed the highest flexural fatigue strength and fused file-splitting resulted in higher fatigue strength than cemented file-splitting. Groups with the framework under tension exhibited higher flexural fatigue strength. 相似文献11.
Objectives
Alignment procedures have yet to be standardised and may influence the measurement outcome. This investigation assessed the accuracy of commonly used alignment techniques and their impact on measurement metrics.Methods
Datasets of 10 natural molar teeth were created with a structured-light model-scanner (Rexcan DS2, Europac 3D, Crewe). A 300 μm depth layer was then digitally removed from the occlusal surface creating a defect of known size. The datasets were duplicated, randomly repositioned and re-alignment attempted using a “best-fit” alignment, landmark-based alignment or reference alignment in Geomagic Control (3D Systems, Darmstadt, Germany). The re-alignment accuracy was mathematically assessed using the mean angular and translation differences between the original alignment and the re-aligned datasets. The effect of the re-alignment on conventional measurement metrics was calculated by analysing differences between the known defect size and defect size after re-alignment. Data were analysed in SPSS v24(ANOVA, post hoc Games Howell test, p < 0.05).Results
The mean translation error (SD) was 139 μm (42) using landmark alignment, 130 μm (26) for best-fit and 22 μm (9) for reference alignment (p < 0.001). The mean angular error (SD) between the datasets was 2.52 (1.18) degrees for landmark alignment, 0.56 (0.38) degrees for best-fit alignment and 0.26 (0.12) degrees for reference alignment (p < 0.001). Using a reference alignment statistically reduced the mean profilometric change, volume change and percentage of surface change errors (p < 0.001).Significance
Reference alignment produced significantly lower alignment errors and truer measurements. Best-fit and landmark-based alignment algorithms significantly underestimated the size of the defect. Challenges remain in identifying reference surfaces in a robust, clinically relevant method. 相似文献12.
Effect of indirect restorative material and thickness on light transmission at different wavelengths
Rafael Rocha Pacheco Adriana Oliveira Carvalho Carolina Bosso André Ana Paula Almeida Ayres Renata Bacelar Catanhede de Sá Tiago Monteiro Dias Frederick Allen Rueggeberg Marcelo Giannini 《Journal of prosthodontic research》2019,63(2):232-238
Purpose
The aim of this study was to evaluate the influence of indirect restorative material type and thickness on the transmission of different wavelengths from a broad-banded dental curing light.Methods
Four dental indirect restorative materials for computer-aided design and computer-aided manufacturing (CAD/CAM) were evaluated: [RC] resin/ceramic hybrid material (Lava Ultimate), [FC] feldspathic ceramic (VitaBlocs), and two zirconia-based ceramics ([ZK] Katana; and [ZL] Lava). Total loss of irradiance (TL) was measured for blue (WB, 425–490 nm) and violet (WV, 350–425 nm) wavelengths. Specimens of 15 × 15 mm with varying thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were fabricated (n = 5). A plasma-arc dental light-curing unit was used (Arc Light-II). To assess TL as a function of wavelength, a software (Spectra Suite v5.1) connected to a spectroradiometer (USB2000) and an integrating sphere (CTSM-LSM-60-SF) was used. Data was subjected to statistical analysis (two-way ANOVA and post-hoc Tukey test, α = 0.05).Results
A 0.5 mm interposition resulted in TL from 50.5 to 67.2%, depending on material. Increased thickness resulted in higher TL for all materials. FC showed less TL compared to ZK. In general, WV showed higher TL than did WB, and WV/WB proportion decreased with increasing thickness.Conclusions
Indirect materials significantly reduced TL, and this effect is greater with increasing thickness. WV showed lower penetration compared to WB. 相似文献13.
Kazuhiro Nagata Satol Hori Ryo Mizuhashi Tomoko Yokoe Yojiro Atsumi Wataru Nagai Motoatu Goto 《Journal of prosthodontic research》2019,63(2):202-209
Purpose
Manual therapy has been used for the treatment of patients with temporomandibular disorders (TMD) with mouth-opening limitations. However, the curative effect of manipulation differs among researchers, and its necessity remains controversial. The purpose of this study was to confirm the efficacy of manipulation using a randomized controlled trial (RCT).Methods
A total of 61 TMD patients who had mouth-opening limitation (upper and lower middle incisor distance ≤35 mm) were selected. They were divided into two treatment groups: conventional treatment (n = 30) and conventional treatment plus manipulation (n = 31). The conventional treatment included two types of self-exercise: cognitive behavioral therapy for bruxism and education. Mouth-opening limitation, orofacial pain, and temporomandibular joint (TMJ) sounds were recorded from baseline to 18 weeks after baseline. These parameters were statistically compared between the two treatment groups by using analysis of variance (ANOVA) and Scheffe’s test to assess mouth opening distance and pain; TMJ sounds were compared using Mann–Whitney U test.Results
No statistical difference was observed between the two treatment groups except for mouth-opening limitation after treatment at the first visit. Subgroup analyses, stratified according to the pathological type of TMD, indicated a similar trend.Conclusions
The efficacy of manipulation seems to be limited, in contrast to our expectations, and improved execution of therapeutic exercises has a similar effect to that of manipulation during long-term observation. The advantage of manipulation was observed only during the first treatment session. The RCT was registered in the University Hospital Medical Information Network in Japan (UMIN-CTR: 000010437). 相似文献14.
Akihiro Ishida Takeshi Wada Koichiro Ogami Takayuki Ueda Kaoru Sakurai 《Journal of prosthodontic research》2019,63(2):162-166
Purpose
This study aimed to clarify the influence of chewing on human β-defensin 2 (hBD-2) and secretory immunoglobulin A (SIgA) expression levels.Methods
We included 15 healthy males with no missing teeth (mean age, 25.5 ± 2.5 years). Subjects were instructed to chew a piece of gum for 30 min. Saliva and skin-extraction samples were collected before and after chewing for 15 and 30 min. hBD-2 and SIgA concentrations in the samples were determined using enzyme-linked immunosorbent assay (ELISA). hBD-2 and SIgA expression levels before and after chewing were analyzed using the Mann–Whitney U test, following the Friedman test. The significance level was 0.05.Results
The hBD-2 level in skin-extraction samples was significantly different before (99.4 ± 17.3 pg/mL) and after chewing for 30 min (142 ± 23.0 pg/mL). The SIgA level in skin-extraction samples was also significantly different before (2.39 ± 0.25 μg/mL) and after chewing for 30 min (3.61 ± 0.33 μg/mL). No significant difference was noted in either hBD-2 or SIgA secretion rate in saliva between before and after chewing.Conclusions
Chewing gum for 30 min increased hBD-2 and SIgA expression levels in skin. Moreover, chewing gum could influence the secretion pattern of these two biomolecules on skin, but not in saliva. 相似文献15.
Christina Boutsiouki Roland Frankenberger Susanne Lücker Norbert Krämer 《Dental materials》2019,35(3):422-433
Objective
To investigate secondary caries inhibition after dentine pre-treatment with 2% CHX, experimental addition of CHX in primer and adhesive of a 3-step adhesive system, and industrial addition od CHX in a 2-step adhesive system.Materials and method
Sixty Class-V cavities were restored according to the adhesive protocol (n = 12): 1) control group, Scotchbond Multi-Purpose, 3M (CTRL), 2) 2% CHX dentine pre-treatment (DENT), 3) 0.1% CHX in primer (PRIM), 4) 0.1% CHX in bonding agent (BOND), 5) Peak Universal Bond including 0.2% CHX (PEAK). Specimens were thermocycled (10,000 cycles) and inserted into a Streptococcus mutans biofilm artificial mouth (caries model). The 10-day biological loading protocol consisted of consecutive phases of demineralisation (1 h) and remineralisation (5 h). Evaluation under a fluorescence microscope (demineralisation) and an SEM (marginal gap) followed, at restoration margins, and at 0.3 mm and 0.5 mm distance from the margins, in enamel and in dentine. Total demineralization was calculated as the sum of demineralisation and substance loss due to demineralisation.Results
PRIM (p = 0.007, mod. LSD), BOND (p = 0.012, mod. LSD) and PEAK (p = 0.008, mod. LSD) exhibited significantly higher total demineralisation values in enamel margins than CTRL. No significant differences were noted for total demineralisation in dentine. Regarding marginal gaps, DENT exhibited significantly lower enamel gap values compared to all other groups (p = 0.001).Conclusions
2% CHX as dentine pre-treatment, 0.1% or 0.2% CHX added in adhesives did not provide any antibacterial effect regarding secondary caries in dentine. On the other hand, 2% CHX dentine pre-treatment managed to limit marginal gap formation in enamel compared to the other adhesive protocols in the study. 相似文献16.
Marla Cuppini Kelly Cristine Zatta Letícia Boldrin Mestieri Fabiana Soares Grecca Vicente Castelo Branco Leitune Sílvia Stanisçuaski Guterres Fabrício Mezzomo Collares 《Dental materials》2019,35(3):457-467
Objective
The aim of this study was to synthesize and characterize an experimental endodontic paste.Methods
An experimental endodontic paste (EX) was characterized by its particle size, zeta potential, drug content and morphology. The powder of EX is composed of amoxicillin microspheres, calcium tungstate and α-tricalcium phosphate, mixed with an indomethacin nanocapsules suspension. Ultracal® (Ultradent), an iodoform-based paste (GP) and the EX were evaluated by its physical properties (flow, film thickness and radiopacity). The cytocompatibility was performed by MTT and SRB-colorimetric assays; the cell-migration was tested with scratch assay and cell-ability to remineralization with ALP and Alizarin Red S, with fibroblastic cell line. The antibacterial activity was assessed by the formation of inhibition zones and against planktonic bacteria.Results
The EX and UL flow achieved ISO6876 standard, and GP was lower than 17 mm. All pastes achieved the film thickness required. Radiopacity was equivalent to 1.81 ± 0.25 mmAl for EX, which did not differ from GP group 1.39 ± 0.33 mmAl (p > 0.05). The UL presented 3.04 ± 0.33 mmAl. The values for SRB showed better citocompatibility in comparison with MTT for all materials. The ALP activity and formation of mineralized nodules demonstrated the remineralization potential for UL and EX. Cell migration showed continuous wound closure until complete cell healing, however, the EX accelerated the process (p < 0.05). The EX showed the greatest inhibition zone (p < 0.05) and was the only group with antibacterial activity against planktonic bacteria.Significance
The synthesized endodontic paste demonstrated reliable physical and biological properties and could be a promising material for periapical tissue repair. 相似文献17.
Tomoaki Mameno Masahiro Wada Yoshinobu Onodera Daiju Fujita Hironobu Sato Kazunori Ikebe 《Journal of prosthodontic research》2019,63(2):216-220
Purpose
The purpose of this study was to evaluate the incidence of peri-implantitis and to identify potential associated risk indicators.Methods
This longitudinal study included 477 patients treated with 1420 implants. Medical and dental histories were evaluated in all patients. The location, size, connection type, surgical protocol, use of prosthesis splinting and fixation type were evaluated for each implant. In peri-implant evaluation, minimum keratinized tissue width around implants, peri-implant probing depths, peri-implant bleeding and peri-implant suppuration were assessed. Bone resorption around implants was evaluated with intraoral radiographs at baseline and at follow-up examinations. The study endpoint was peri-implantitis, which was defined as the presence of bleeding on probing and/or suppuration with bone resorption >1 mm, in accordance with previous studies. Data were analyzed with mixed-effects Cox models.Results
Peri-implantitis occurred in 15.3% of patients and 9.2% of implants. The overall 5- and 10-year cumulative implant survival rates were 0.95 (95% confidence interval [CI]: 0.93–0.96) and 0.83 (95% CI: 0.8–0.87), respectively. Age (hazard ratio [HR] = 0.94, 95% CI: 0.90–0.98, p < 0.01), plaque control record >20% (HR = 2.61, 95% CI: 1.02–6.67, p = 0.04), maxillary placement (HR = 1.90, 95% CI: 1.11–3.23, p = 0.02) and number of occlusal supports (HR = 0.87, 95% CI: 0.77–0.99, p = 0.03) were significantly correlated with peri-implantitis development.Conclusions
Within the limitations of this longitudinal study on risk indicators for peri-implantitis, age, inadequate plaque control, insertion in the maxilla and less occlusal support of natural teeth correlated with peri-implantitis development. 相似文献18.
Thwe Zin Ei Yasushi Shimada Ahmed Abdou Alireza Sadr Masahiro Yoshiyama Yasunori Sumi Junji Tagami 《Dental materials》2019,35(4):e74-e82
Objective
The purpose of this study was to detect and investigate the association of enamel microcracks with demineralization at proximal contact areas of premolars, using 3D swept-source optical coherence tomography (SS-OCT).Methods
Extracted maxillary and mandibular premolars (n = 50 each), without any visible tooth cracks, were examined for demineralization of interproximal contact areas, using the International Caries Detection and Assessment System (ICDAS). SS-OCT was used to evaluate demineralization and detect microcracks. Demineralization progression was divided into 4 types by depth: 0 for sound enamel and Type I, II, and III for enamel demineralization penetrating into the outer third, the middle third, and the inner third of the enamel thickness, respectively. Enamel microcracks were classified according to the predominant crack pattern: Type O, no cracks; Type A, subsurface microdefects; Type B, enamel microcrack running along the direction of the enamel prism; Type C, enamel microcrack running transverse to the enamel prism direction; and Type D, a combination of patterns A, B, and C. SS-OCT findings were confirmed by confocal laser scanning microscopy observation.Results
Microcracks confined within the superficial enamel in proximal contact areas were seen as bright lines on SS-OCT. There were significant positive correlations among ICDAS codes, demineralization levels, and microcrack distribution (p ≤ 0.001). The mesial side of maxillary premolars showed significantly more demineralization (n = 36) and microcracks (n = 27) than that of the mandibular premolars (n = 20 and n = 14, respectively; p < 0.001).Significance
The presence of microcracks within the superficial enamel in proximal contact areas could be determined using SS-OCT, and correlated with the level of demineralization. 3D SS-OCT is a valuable diagnostic tool for comprehensive assessment of microstructural changes related to enamel demineralization and crack development. 相似文献19.
Shruti Vidhawan Agarwalla Kassapa Ellepola Mariana Caldeira Ferraz da Costa Guilhermino José Macêdo Fechine Julien Luc Paul Morin A.H. Castro Neto Chaminda Jayampath Seneviratne Vinicius Rosa 《Dental materials》2019,35(3):403-413
Objective
To evaluate the surface and wettability characteristics and the microbial biofilm interaction of graphene coating on titanium.Methods
Graphene was deposited on titanium (Control) via a liquid-free technique. The transfer was performed once (TiGS), repeated two (TiGD) and five times (TiGV) and characterized by AFM (n = 10), Raman spectroscopy (n = 10), contact angle and SFE (n = 5). Biofilm formation (n = 3) to Streptococcus mutans, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans was evaluated after 24 h by CV assay, CFU, XTT and confocal microscopy. Statistics were performed by one-way Anova, Tukey’s tests and Pearson’s correlation analysis at a pre-set significance level of 5 %.Results
Raman mappings revealed coverage yield of 82 % for TiGS and ≥99 % for TiGD and TiGV. Both TiGD and TiGV presented FWHM > 44 cm?1 and ID/IG ratio < 0.12, indicating multiple graphene layers and occlusion of defects. The contact angle was significantly higher for TiGD and TiGV (110° and 117°) comparing to the Control (70°). The SFE was lower for TiGD (13.8 mN/m) and TiGV (12.1 mN/m) comparing to Control (38.3 mN/m). TiGD was selected for biofilm assays and exhibited significant reduction in biofilm formation for all microorganisms compared to Control. There were statistical correlations between the high contact angle and low SFE of TiGD and decreased biofilm formation.Significance
TiGD presented high quality and coverage and decreased biofilm formation for all species. The increased hydrophobicity of graphene films was correlated with the decreased biofilm formation for various species. 相似文献20.
Yutao Jian Li Dao Xiaodong Wang Xinping Zhang Michael V. Swain Ke Zhao 《Dental materials》2019,35(4):e83-e95