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1.
J Dent ; 83: 12-17, 2019 04.
Article in English | MEDLINE | ID: mdl-30716452

ABSTRACT

OBJECTIVES: The objective of this randomized controlled trial was to assess the influence of use of posts as well as the type of posterior tooth (premolars vs molars) for the treatment with lithium disilicate (LS2) partial crowns. MATERIALS AND METHODS: A total of 60 patients were treated with posterior LS2 partial crowns. Two groups (n = 60) were made based on the type of restored tooth: Group 1, premolars and Group 2, molars. The samples of each group were divided into 2 subgroups (n = 30): Subgroup A restored with fiber posts and Subgroup B without them. Clinical and intraoral radiographic examinations were assessed during each recall (6 months and, 1, 2, and 3 years). Kaplan-Meier log-rank test and Cox regression analysis (Pp < 0.05) were applied. RESULTS: Three subgroups showed 100% of survival while group 2 A exhibited the lowest performance (93.3%). The Cox regression analysis showed that the presence of the post was not a significant factor for survival time (Hazard Ratio HR = 0388; CI95% Confidence Interval for H R = 0,1- to 1,5; pp = 017). Tooth type had an influence on survival time that was at the limit of statistical significance (Hazard Ratio HR = 0123; CI95% Confidence Interval for HR = 0 0015- to 0997; p = 005). Particularly, failure risk was greater for premolars. 'Post by tooth type' interactions were not statistically significant (p = 0126). CONCLUSIONS: over a 3-year observation period, the clinical performance of endodontically treated teeth restored with lithium disilicate partial crowns was not significantly affected by the use of a fiber post and by the type of tooth (premolars or molars).


Subject(s)
Crowns , Dental Porcelain , Tooth, Nonvital , Dental Prosthesis Design , Dental Restoration Failure , Follow-Up Studies , Humans , Post and Core Technique , Prospective Studies
2.
Oper Dent ; 43(1): 90-100, 2018.
Article in English | MEDLINE | ID: mdl-29284101

ABSTRACT

OBJECTIVE: To assess the efficacy of dedicated finishing/polishing systems on roughness and gloss of VITA Suprinity and IPS e.max CAD. METHOD: A total of 24 blocks of Suprinity and 24 of e.max were cut into a wedge shape using an InLab MC-XL milling unit. After crystallization, the 24 Suprinity wedges were divided into four subgroups: group A.1: Suprinity Polishing Set Clinical used for 30 seconds and group A.2: for 60 seconds; group A.3: VITA Akzent Plus Paste; and group A.4: spray. The 24 e.max wedges (group B) were divided into four subgroups according to the finishing procedure: group B.1: Optrafine Ceramic Polishing System for 30 seconds and group B.2: for 60 seconds; group B.3: IPS e.max CAD Crystall/Glaze paste; and group B.4: spray. After finishing/polishing, gloss was assessed with a glossmeter and roughness evaluated with a profilometer. Results were analyzed by applying a two-way analysis of variance for gloss and another for roughness (α=0.05). One specimen per each subgroup was observed with a scanning electron microscope. RESULTS: For roughness, materials and surface were significant factors ( p<0.001). Suprinity exhibited significantly lower roughness than e.max. Also the Material-Surface Treatment interaction was statistically significant ( p=0.026). For gloss, both material and surface treatment were significant factors ( p<0.001). VITA Suprinity showed significantly higher gloss than e.max. Also the Material-Surface Treatment interaction was statistically significant ( p<0.001). CONCLUSIONS: Manual finishing/polishing for 60 seconds and glazing paste are the most effective procedures in lowering the roughness of CAD/CAM silica-based glass ceramics. Manual finishing/polishing for 60 seconds allows milled silica-based glass ceramics to yield a higher gloss. VITA Suprinity displayed higher polishability than IPS e.max CAD.


Subject(s)
Ceramics , Computer-Aided Design , Dental Polishing , Dental Porcelain , Dental Restoration, Permanent/methods , Zirconium , Ceramics/therapeutic use , Dental Porcelain/therapeutic use , Humans , In Vitro Techniques , Lithium , Silicates , Surface Properties , Zirconium/therapeutic use
4.
Oper Dent ; 40(4): 440-8, 2015.
Article in English | MEDLINE | ID: mdl-25602350

ABSTRACT

OBJECTIVE: The aim of the study was to compare in Class V composite restorations marginal leakage measurements obtained with microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) observations. METHODS: Class V cavities were prepared on 10 human molars and restored using Optibond FL (Kerr, Orange, CA, USA) and Premise Flowable (Kerr). Sealing ability was evaluated by assessing silver-nitrate penetration depth along enamel and dentin margins. Leakage was quantified using a scoring system. Micro-CT analysis provided 502 cross-sectional images for each tooth. Microleakage evaluation was performed first on three cross-sections corresponding to the sections examined by SEM, then on all 502 of the obtained micro-CT images. SEM observations were performed first at 20× magnification, then, if showing a zero score, at 80× magnification. Enamel and dentin microleakage scores assigned to corresponding sections through micro-CT and SEM (20×) were compared (Wilcoxon signed-rank test, α=0.05). RESULTS: No statistically significant difference in leakage scores emerged between micro-CT and 20×-magnification SEM. Eight tooth sections that were given a zero score under SEM at 20× magnification showed to be infiltrated at the higher magnification (80×). For five teeth a higher score was assigned following scanning of 502 cross-sections than based on the observation of three sections. CONCLUSIONS: Micro-CT presents as a valid, nondestructive in vitro method to quantitatively evaluate marginal leakage of adhesive restorations.


Subject(s)
Composite Resins , Dental Leakage/diagnostic imaging , Dental Restoration, Permanent , Microscopy, Electron, Scanning , X-Ray Microtomography , Dental Caries/therapy , Dental Cavity Preparation , Dental Enamel , Dental Marginal Adaptation , Dentin , Humans , Molar/anatomy & histology , Molar/diagnostic imaging , Resin Cements
5.
Int Endod J ; 48(1): 60-7, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24611944

ABSTRACT

AIM: To verify whether the filler load of luting agents influences the radiopacity of intraradicularly placed posts. METHODOLOGY: Digital radiographs of the following posts were taken: RelyX Fiber Post (3M ESPE), GC Fiber Post (GC Corporation), DT Light Post Illusion (RTD), DT Light SL Post (RTD), Endo-Composipost (RTD), FibreKleer Parallel Post (Jeneric Pentron Incorporated), FRC Postec (Ivoclar Vivadent), Parapost Taper Lux (Còltene/Whaledent AG), Radix Fiber Post (Dentsply Maillefer), EverStick Post (Stick Tech Ltd), Dentin Post X (Komet), Tech 21 X-op (Isasan), ENA Post (Micerium). Post radiopacity was measured in millimetres of aluminium (mmAl) with reference to an aluminium step wedge. Two extracted contralateral premolars were root filled. After post space preparation, taking the midpoint of the post hole as a reference, each tooth was cut longitudinally into two halves in a mesiodistal direction. On each half, the exposed root dentine was ground flat to the deepest point of the post space, and an even layer of cement was placed and light-cured. To obtain a clinically relevant layer of cement, the material thickness was reduced to 75 µm by grinding with wet abrasive paper. A cement formulation with 30 wt% of filler was tested in one premolar, whilst a formulation with 70 wt% of filler was utilized in the contralateral tooth. Posts were then placed between the two facing root halves of each premolar, and radiopacity was measured in mmAl. Data were analysed using t-test for paired samples (P < 0.05). RESULTS: Radiopacity of posts ranged between 1.44 (ENA Post) and 5.78 mmAl (FibreKleer). In the presence of the more heavily filled cement, significantly higher values of post radiopacity were measured (P < 0.001). CONCLUSION: The radiopacity of the luting agent contributed to the overall post radiovisibility within the root. Even when the cement with lower filler content was used in combination with the least radiodense dowels, the post was detectable within the root.


Subject(s)
Bicuspid/diagnostic imaging , Dental Cements/chemistry , Dental Pulp Cavity/diagnostic imaging , Post and Core Technique/instrumentation , Radiography, Dental, Digital , Root Canal Obturation/methods , Humans , In Vitro Techniques , Materials Testing , Surface Properties
6.
J Dent Res ; 93(7 Suppl): 52S-58S, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24646637

ABSTRACT

The objective of this prospective clinical trial was to investigate the influence of the residual coronal structure of endodontically treated teeth and the type of cement used for luting fiber posts on four-year clinical survival. Two groups (n = 60) were defined, depending on the amount of residual coronal dentin after abutment build-up and final preparation: (1) more than 50% of coronal residual structure; and (2) equal to or less than 50% of coronal residual structure. Within each group, teeth were randomly divided into 2 subgroups (n = 30) according to the material used for luting fiber posts: (A) resin core build-up material, Gradia Core; or (B) self-adhesive universal cement GCem Automix. The rate of success was assessed based on clinical and intra-oral radiographic examinations at the follow-up after 6, 12, 24, 36, and 48 months. The highest 48-month success and survival rates were recorded in group 1A (90% and 100%, respectively), whereas teeth in group 2B exhibited the lowest performance (63.3% success rate, 86.6% survival rate). Cox regression analysis revealed that neither the amount of coronal residual structure nor the luting material significantly influenced the failure risk (p > .05) (ClinicalTrials.gov, NCT01532947).


Subject(s)
Bicuspid/pathology , Post and Core Technique/instrumentation , Tooth, Nonvital/therapy , Adolescent , Adult , Aged , Composite Resins/chemistry , Dental Abutments , Dental Materials/chemistry , Dental Restoration Failure , Dentin/pathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Periapical Diseases/etiology , Prospective Studies , Radiography, Bitewing , Resin Cements/chemistry , Survival Analysis , Tooth Crown/pathology , Tooth Fractures/etiology , Tooth Preparation, Prosthodontic/methods , Tooth Root/injuries , Treatment Outcome , Young Adult
7.
Oral Implantol (Rome) ; 7(1): 11-9, 2014.
Article in English | MEDLINE | ID: mdl-25694796

ABSTRACT

AIM: In this preliminary study, the 3-year radiological outcomes of Osseospeed implant-supported fixed complete or partial prostheses made with two different laboratory protocols were compared. METHODS: A convenience sample of 34 patients, who were either partially or completely edentulous in either jaw, were randomly assigned to two groups, of 17 patients each, using either a traditional laboratory protocol (control group) or the Cresco one (test group). The study's objective was an assessment of marginal bone loss around implants, measured on intraoral radiographs at 3-year follow-up. RESULTS: None of the implants inserted was lost during the study and radiological measurements of marginal bone level changes revealed that the mean marginal bone loss was respectively 0,73±0,33mm for test group and 0,88±1,13mm for control group. The differences between test and control groups were not statistically significant. CONCLUSION: This preliminary study did not demonstrate statistically significant differences in marginal bone loss around implant-prostheses prepared with the two different laboratory protocols, over the 3-year observational period.

8.
J Clin Pediatr Dent ; 37(4): 397-402, 2013.
Article in English | MEDLINE | ID: mdl-24046989

ABSTRACT

OBJECTIVE: To evaluate the applicability as a sealant of a new self-adhering flowable resin composite (Vertise Flow, Kerr, VF) by assessing shear bond strength (SBS) to unground enamel and microleakage (microLKG) in sealed pits and fissures. STUDY DESIGN: Marketed sealants to be used in combination with phosphoric acid (Guardian Seal, Kerr, GS) or with a self-etch adhesive (Adper Prompt-L-Pop/Clinpro Sealant, 3M ESPE, CS) were compared to VF. For SBS testing on unground enamel 10 molars per group were used. For microLKG assessment, pits and fissures sealing was performed in 12 molars per group. The sealed teeth were immersed in a 50% weight silver nitrate solution for 24 hours and the extent of interfacial leakage was measured. Between-group differences in SBS were assessed using One-Way Analysis of Variance (ANOVA), followed by Tukey test (p < 0.05). microLKG data were analyzed with Kruskall-Wallis ANOVA (p > 0.05). RESULTS: SBS of VF was statistically similar to that measured by CS and higher than that of GS. Interfacial leakage was similar in the three groups. CONCLUSIONS: The finding of satisfactory bond strength and sealing ability of VF when compared to the marketed sealants encourages the use of VF in pit and fissure sealing.


Subject(s)
Composite Resins , Dental Bonding , Pit and Fissure Sealants , Resin Cements , Analysis of Variance , Dental Enamel , Dental Leakage/prevention & control , Dental Stress Analysis , Humans , Shear Strength , Statistics, Nonparametric , Viscosity
9.
J Dent Res ; 91(7 Suppl): 72S-78S, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22699672

ABSTRACT

This in vivo study examined the contribution of remaining coronal dentin and placement of a prefabricated (LP) or customized fiber post (ES) to the six-year survival of endodontically treated premolars. A sample of 345 patients provided 6 groups of 60 premolars each in need of endodontic treatment. Groups were classified according to the number of remaining coronal walls before abutment build-up. Within each group, teeth were allocated to one of three subgroups: (A) no post retention; (B) LP; or (C) ES (N = 20). All teeth were protected with a crown. Cox regression analysis revealed that fiber post retention significantly improved tooth survival (p < 0.001). Failure risk was lower in teeth restored with prefabricated (p = 0.001) than with customized posts (p = 0.009). Teeth with one (p = 0.004), two (p < 0.001), and three coronal walls (p < 0.001) had significantly lower failure risks than those without ferrule. Similar failure risks existed for teeth without coronal walls, regardless of the presence/absence of ferrule (p = 0.151). Regardless of the restorative procedure, the preservation of at least one coronal wall significantly reduced failure risk (ClinicalTrials.gov number CT01532947).


Subject(s)
Bicuspid/pathology , Post and Core Technique , Tooth, Nonvital/therapy , Crowns , Dental Abutments , Dental Bonding , Dental Prosthesis Design , Dental Prosthesis Retention , Dental Restoration Failure , Dentin/pathology , Follow-Up Studies , Humans , Post and Core Technique/instrumentation , Prospective Studies , Root Canal Therapy , Tooth Fractures/etiology , Tooth Root/injuries , Treatment Outcome
10.
Aust Dent J ; 57(2): 220-6, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22624765

ABSTRACT

BACKGROUND: The aim of this study was to evaluate the influence of preliminary phosphoric acid etching on the microleakage of a self-adhering flowable composite and a self-etch adhesive used in combination with the proprietary flowable composite. METHODS: Standard Class V cavities were prepared on the buccal side of 20 extracted sound human molars. Specimens were randomly divided into five groups: (1) Gel Etchant/Optibond FL/Premise Flowable; (2) Vertise Flow; (3) Optibond XTR/Premise Flowable; (4) Gel Etchant/Vertise Flow; and (5) Gel Etchant/Optibond XTR/Premise Flowable (Kerr). The interfacial sealing ability of the materials was evaluated by scoring the depth of silver nitrate penetration and through scanning electron microscopy observations. Differences in leakage at either the enamel or the dentine interface were evaluated for statistical significance (Kruskal-Wallis ANOVA, Mann-Whitney U test, p < 0.05). RESULTS: At the enamel interface, no significant differences were found among the materials. On dentine, Gel Etchant/Vertise Flow had the highest leakage scores and the difference was statistically significant (p < 0.05). CONCLUSIONS: The early sealing ability of the self-adhering flowable composite and the self-etch adhesive in Class V restorations did not significantly benefit from selective enamel etching. Preliminary phosphoric acid etching of dentine negatively affected the quality of the seal when using the adhesive-free flowable composite.


Subject(s)
Acid Etching, Dental , Composite Resins , Dental Leakage , Dental Restoration, Permanent/methods , Resin Cements , Dental Bonding , Dental Enamel , Dental Restoration, Permanent/classification , Dentin , Humans , Materials Testing , Phosphoric Acids , Statistics, Nonparametric , Tooth Cervix
11.
Oper Dent ; 37(1): 28-36, 2012.
Article in English | MEDLINE | ID: mdl-21942241

ABSTRACT

OBJECTIVES: To evaluate the compatibility between aged siloranes and methacrylate-based composites by simulating a common repair-technique. METHODS: Twenty substrates were constructed using silorane (Filtek Silorane, 3M ESPE) and methacrylate composites (Filtek Supreme XT, 3M ESPE). Substrates were aged in 0.9% NaCl solution at 37°C for 72 hours. Silorane build-ups were constructed on silorane substrates without any intermediate layer (IL). Methacrylate build-ups were constructed on silorane substrates without any IL, with a methacrylate IL (Heliobond, Ivoclar Vivadent), or with a phosphate-methacrylate IL (Silorane System Adhesive Bond, 3M ESPE). Methacrylate build-ups were also constructed on methacrylate substrates without any IL. The micro-shear bond strength test was carried out after thermocycling. Bond strength data were statistically analyzed using analysis of variance and Tukey post hoc tests. Failure modes were assessed by means of scanning electron microscopy observations. RESULTS: The silorane-methacrylate group without any IL showed the lowest bond strength values (0.4 ± 0.1 MPa). The use of a methacrylate-based IL (1.6 ± 1.7 MPa) led to a slight increase in bond strength, whereas the use of phosphate-methacrylate IL (9.1 ± 5.4 MPa) significantly increased bond strength. There was no statistically significant difference in bond strength between silorane-silorane (7.9 ± 3.6 MPa) and methacrylate-methacrylate (9.5 ± 4.1 MPa) groups without any IL.


Subject(s)
Composite Resins/chemistry , Dental Bonding/methods , Methacrylates/chemistry , Siloxanes/chemistry , Acrylates/chemistry , Acrylic Resins/chemistry , Dentin-Bonding Agents/chemistry , Humans , Materials Testing , Microscopy, Electron, Scanning , Organophosphates/chemistry , Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Shear Strength , Silorane Resins , Sodium Chloride/chemistry , Stress, Mechanical , Surface Properties , Temperature , Time Factors
12.
Aust Dent J ; 56 Suppl 1: 77-83, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21564118

ABSTRACT

This literature review summarizes the most recent and reliable evidence on post systems. A search was limited to review articles published over the last 10 years in dental journals with an impact factor. Papers cited in the initially retrieved review articles were also included if significant. Preservation of tooth tissue, presence of a ferrule effect, and adhesion are regarded as the most effective conditions for long-term success of post-endodontic restorations. Adhesively luted fibre-reinforced composite post restorations have demonstrated satisfactory survival rates over relatively long follow-up periods. The clinical effectiveness of such restorations has been mainly ascribed to the more biomimetic behaviour of fibre-reinforced composite posts that reduces the risk of vertical root fractures. The most common type of failure when using fibre posts is post debonding and it is generally agreed that achieving stable adhesion to intraradicular dentine is more challenging than to coronal dentine. Several factors related to endodontic treatment, root canal shape, post space preparation, post translucency, adhesive cement handling and curing may have an influence on the outcome of the luting procedure. The most reliable results in fibre post cementation are obtained by etch-and-rinse adhesives in combination with dual-cure resin cements. The use of self-adhesive resin cements has also been proposed. Simplification is an obvious advantage of these new materials. However, the durability of their bond still needs to be verified with long-term clinical studies. Several techniques for pre-treating the fibre-reinforced composite post surface have been tested with the aim of improving the bond strength at the post-core and post-cement interfaces. Silicoating followed by silanization currently appears to be the most effective and convenient method for this purpose. In conclusion, the available evidence validates the use of fibre posts as an alternative to metal posts and preferably to other tooth-coloured posts, such as zirconia dowels, in the restoration of endodontically treated teeth. Longer term clinical trials are expected to further strengthen this evidence.


Subject(s)
Dental Bonding , Post and Core Technique , Composite Resins , Dental Alloys , Dental Porcelain , Glass , Humans , Polyethylenes , Quartz , Zirconium
13.
J Dent Res ; 88(10): 951-6, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19783806

ABSTRACT

Luting of fiber posts to intra-radicular dentin represents the worst-case scenario in terms of control of polymerization shrinkage. This study tested the hypothesis that filler content of resin cements does not influence luting of fiber posts to intra-radicular dentin, by assaying polymerization stress, push-out bond strength, and nanoleakage expression. The polymerization stress of experimental cements containing 10%, 30%, 50%, or 70% in filler content was investigated. Post spaces were prepared in endodontically treated teeth, and fiber posts were cemented with the experimental cements. A push-out test was performed, and interfacial nanoleakage expression was analyzed. Results showed that luting cements with higher filler content were related to increased polymerization stress (p < 0.05), decreased push-out bond strength (p < 0.05), and increased interfacial nanoleakage expression (p < 0.05). Conversely, lower-stress luting materials increased bonding of fiber posts to intra-radicular dentin. Further in vivo studies are needed to investigate the long-term clinical performance of these materials.


Subject(s)
Cementation/methods , Dental Bonding , Post and Core Technique/instrumentation , Resin Cements/chemistry , Adhesiveness , Aluminum Compounds/chemistry , Dental Leakage/classification , Dental Prosthesis Design , Dental Pulp Cavity/ultrastructure , Dentin/ultrastructure , Dentin-Bonding Agents/chemistry , Fluorides/chemistry , Humans , Materials Testing , Methacrylates/chemistry , Particle Size , Polymers/chemistry , Polyurethanes/chemistry , Silicon Compounds/chemistry , Silicon Dioxide/chemistry , Stress, Mechanical , Surface Properties , Tooth, Nonvital/pathology
14.
Int Endod J ; 42(2): 129-35, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19134041

ABSTRACT

AIM: To examine the effect of the application of an ethanol rinse before luting fibre posts to intraradicular dentine with etch-and-rinse adhesive systems by means of push-out bond strength evaluation and scanning electron microscopic (SEM) analysis. METHODOLOGY: Fibre posts were luted to single-canal premolars using Dual Link as a luting agent in combination with a three-step (All Bond 2) or a two-step (One Step Plus) etch-and-rinse adhesive system, which were applied as per manufacturers' instructions (control) or with the additional rinse of ethanol on acid-etched dentine prior to the bonding procedures (experimental). Bonded specimens were sectioned into 1-mm-thick slabs and subjected to push-out bond strength testing. In addition, specimens from each group were processed for SEM analysis. Data were analysed by Kruskal-Wallis followed by Dunn's post hoc test at P = 0.05. RESULTS: Push-out bond strength of All Bond 2 was significantly increased if the adhesive was applied on ethanol-saturated dentine (P < 0.05), whilst no significant difference (P > 0.05) was detected amongst experimental and control groups for One Step Plus. Irrespective of the adhesive, the SEM analysis revealed good impregnation patterns when both bonding techniques were employed. CONCLUSIONS: The use of the additional ethanol rinse on acid-etched dentine revealed higher bond strength of All Bond 2 when compared with the control application procedure, used in combination with a resin-based cement to lute fibre posts into the dowel space. However, no bond strength improvements were detected using One Step Plus. Further investigations are needed to develop a clinically applicable ethanol/bonding/luting technique.


Subject(s)
Dental Bonding , Dentin-Bonding Agents/chemistry , Dentin/ultrastructure , Ethanol/chemistry , Post and Core Technique/instrumentation , Solvents/chemistry , Acid Etching, Dental , Dental Pulp Cavity/ultrastructure , Humans , Materials Testing , Methacrylates/chemistry , Microscopy, Electron, Scanning , Resin Cements/chemistry , Silanes/chemistry , Stress, Mechanical , Surface Properties
15.
J Dent Res ; 87(12): 1122-6, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19029079

ABSTRACT

If proper polymerization of resin-based cements is to be achieved for fiber post luting, light activation is needed for photo-curing agents, recommended for self-curing materials. The study was aimed at verifying whether the light-transmitting ability of marketed fiber posts reflected the manufacturers' claims for translucency. Ten posts per type were light-irradiated with a curing unit. Spectrophotometric measurements of the amount of photons reaching different post levels were taken. Data were statistically analyzed (linear regression, two-way ANOVA; alpha = 0.05). No light transmission was recorded through FibreKleer and Tech21 X-OP. For the other posts, light intensity decreased from coronal to apical and rose again at the apical tip, where it peaked for GC Fiber Post, Macrolock Illusion Post, and Radix Fiber Post. Light transmission was significantly higher at the coronal level. A statistically significant difference in translucency was found for Dentin Post X and FRC Postec Plus in comparison with Reforpost, FibreKleer, Tech21 X-OP, and Composipost.


Subject(s)
Dental Materials/chemistry , Dental Prosthesis Design , Optical Phenomena , Post and Core Technique/instrumentation , Bisphenol A-Glycidyl Methacrylate/chemistry , Bisphenol A-Glycidyl Methacrylate/radiation effects , Carbon/chemistry , Carbon/radiation effects , Carbon Fiber , Composite Resins/chemistry , Composite Resins/radiation effects , Dental Materials/radiation effects , Epoxy Resins/chemistry , Epoxy Resins/radiation effects , Glass/chemistry , Glass/radiation effects , Humans , Image Processing, Computer-Assisted , Light , Photons , Quartz/chemistry , Quartz/radiation effects , Silicon Dioxide/chemistry , Silicon Dioxide/radiation effects , Spectrophotometry , Surface Properties , Zirconium/chemistry , Zirconium/radiation effects
16.
J Dent ; 36(10): 801-7, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18621457

ABSTRACT

OBJECTIVES: To evaluate the effect of immediate versus delayed post space preparation and cementation on the retention of different types of fiber posts in canals obturated with an epoxy resin sealer. METHODS: Sixty-eight single-rooted human teeth were decoronated and the root canals were shaped with rotary instruments and obturated with gutta-percha and an epoxy resin sealer. The teeth were divided into four experimental groups according to the different times of post space preparation and cementation: immediate (group 1), 24h (group 2) and 1 week (group 3) after root canal filling. Control group (group 4) with no root canal obturation was included. Two teeth were randomly selected from each group for SEM examination. Each group was further divided into three subgroups of five teeth each (n=5), according to the type of post and the materials used for luting the posts. A push-out test was performed and differences among experimental groups were analyzed with two-way ANOVA and Tukey test (alpha=0.05). RESULTS: Interfacial strength values achieved in group 1, where an immediate cementation was performed, were significantly lower (p<0.05) than those in group 2 and group 3 in which post cementation was performed 24h or 1 week after the root canal filling. Post type affected post retention, FRC Postec and DT Light Post posts achieved higher interfacial strengths than ENA Post (p<0.05). SEM examination revealed a more conspicuous presence of sealer remnants on the walls of immediately prepared post spaces. CONCLUSIONS: Delayed cementation of fiber post resulted in higher retentive strengths irrespective of the post type.


Subject(s)
Dental Bonding/methods , Dental Prosthesis Retention , Epoxy Resins/therapeutic use , Post and Core Technique , Root Canal Obturation/methods , Analysis of Variance , Dental Marginal Adaptation , Dental Stress Analysis , Gutta-Percha/therapeutic use , Humans , Materials Testing , Root Canal Filling Materials/therapeutic use , Statistics, Nonparametric , Time Factors , Tooth Preparation, Prosthodontic/methods
17.
J Dent Res ; 86(8): 729-34, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17652200

ABSTRACT

Clinical evidence is lacking regarding the influence of the amount of residual coronal dentin and of post placement on the failure risk of endodontically compromised teeth. The aim of this prospective clinical trial was to assess whether these factors significantly affect the two-year survival of restored pulpless premolars. A sample of 210 individuals provided six experimental groups of 40 premolars in need of endodontic treatment. Groups were defined based on the amount of dentin left at the coronal level. Within each group, in half of the teeth selected at random, a fiber post was inserted inside the root canal, whereas in the remaining half of the premolars, no post was placed. All teeth were covered with a crown. The Cox regression analysis revealed that post placement resulted in a significant reduction of failure risk (p < 0.001). Failure risk was increased for teeth under the "no ferrule" (p = 0.001) and "ferrule effect" conditions (p = 0.004).


Subject(s)
Dental Restoration Failure , Post and Core Technique , Adolescent , Adult , Aged , Bicuspid , Crowns , Dentin/physiology , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Proportional Hazards Models , Prospective Studies
18.
Int Endod J ; 39(1): 31-9, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16409326

ABSTRACT

AIM: To evaluate the influence of various surface treatments to fibre posts on the microtensile bond strength with different composite resins. METHODOLOGY: A total of 110 fibre posts were randomly divided into five groups, according to the surface pre-treatment performed. Group 1: immersion in 24% H(2)O(2) for 10 min and silanization for 60 s; group 2: immersion in 10% H(2)O(2) for 20 min and silanization for 60 s; group 3: immersion in 4% hydrofluoric acid gel for 60 s and silanization for 60 s; group 4: silanization of the post surface for 60 s and application of the bonding agent G-Bond; group 5: silanization of the post surface for 60 s (control group). After treatment, two posts were randomly selected from each group to evaluate the morphological aspect of the post surface with scanning electron microscopy. The remaining posts in each group were divided into five subgroups of five posts each, which differed in the type of composite resin used for the core build-up. Post-core strength were calculated and the differences among experimental groups were analysed with two-way anova and the Tukey test (alpha = 0.05). RESULTS: The post-core strengths achieved in groups 1 and 2 were significantly higher (P < 0.05), than those of groups 3, 4 and 5. The post-core strength in the control group was significantly lower (P < 0.05) than all other groups. CONCLUSIONS: Hydrogen peroxide and hydrofluoric acid both modified the surface morphology of fibre posts and with silane, significantly enhanced the interfacial strength between them and core materials.


Subject(s)
Acrylic Resins/chemistry , Composite Resins/chemistry , Hydrofluoric Acid/administration & dosage , Hydrogen Peroxide/administration & dosage , Polyurethanes/chemistry , Post and Core Technique , Microscopy, Electron, Scanning , Oxidants/administration & dosage , Surface Properties/drug effects , Tensile Strength/drug effects
19.
Int Endod J ; 37(10): 679-86, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15347292

ABSTRACT

AIM: To evaluate the ability of two luting procedures for bonding translucent fibre posts to form resin tags, adhesive lateral branches, and resin dentine interdiffusion zones (RDIZ). METHODOLOGY: Forty root filled teeth, extracted for periodontal reasons, were selected for the study. The teeth were randomly divided into four groups of 10 each. Group 1: One Step, light-cured (LC) 20 s + dual link resin cement (LC 20 s); group 2: One Step, not light-cured (NLC) + dual link resin cement (LC 30 s); group 3: One Step (NLC) + dual link resin cement (LC 60 s); group 4: One Step (NLC) + dual link resin cement (LC 90 sec). Forty translucent fibre posts (DT posts, RTD) were inserted. Then, root specimens were processed for scanning electron microscope (SEM) observations to assess the continuity of the RDIZ, the presence or absence of gaps and the density and morphology of resin tags using a four-step scale method. RESULTS: With all luting procedures the formation of a RDIZ occurred. However, the microscopic examination of adhesive interfaces revealed that the percentage of RDIZ was significantly higher in group 1 than in the other three groups (P < 0.05). Group 4 had a higher percentage of RDIZ than group 3, which in turn exhibited a greater percentage than group 2, but these differences were not statistically significant (P > 0.05). Resin tag formation was evident in all the groups. The characteristic reverse cone shape of resin tags was always noted in the coronal and middle third of all groups, and in the apical third of group 1. In the apical third a shorter length and a less uniform appearance of resin tags were noted in groups 2, 3 and 4. CONCLUSIONS: In this laboratory study, when bonding a translucent fibre post into a root canal, the luting procedure including light curing of the adhesive solution before the placement of the cement was more satisfactory, from a SEM standpoint, than the procedure involving the simultaneous curing of adhesive and cement (one step procedure).


Subject(s)
Dental Bonding/methods , Post and Core Technique , Resin Cements , Dentin/ultrastructure , Dentin Permeability , Dentin-Bonding Agents , Glass , Humans , Light , Methacrylates , Microscopy, Electron, Scanning , Phase Transition
20.
J Dent Res ; 83(6): 459-64, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15153452

ABSTRACT

Adhesive dentistry should effectively restore the peripheral seal of dentin after enamel removal. We hypothesize that non-rinsing, simplified, one-step self-etch adhesives are effective for minimizing dentin permeability after tooth preparation procedures. Crown preparations in vital human teeth were sealed with Adper Prompt, Xeno III, iBond, or One-Up Bond F. Epoxy resin replicas were produced from polyvinyl siloxane impressions for SEM examination. Dentin surfaces from extracted human teeth were bonded with these adhesives and connected to a fluid-transport model for permeability measurements and TEM examination. Dentinal fluid droplets were observed from adhesive surfaces in resin replicas of in vivo specimens. In vitro fluid conductance of dentin bonded with one-step self-etch adhesives was either similar to or greater than that of smear-layer-covered dentin. TEM revealed water trees within the adhesives that facilitate water movement across the polymerized, highly permeable adhesives. Both in vitro and in vivo results did not support the proposed hypothesis.


Subject(s)
Dentin Permeability/physiology , Dentin-Bonding Agents/chemistry , Acid Etching, Dental , Adult , Compomers/chemistry , Crowns , Dentin-Bonding Agents/classification , Dentinal Fluid/chemistry , Diffusion Chambers, Culture , Humans , Materials Testing , Methacrylates/chemistry , Microscopy, Electron , Microscopy, Electron, Scanning , Replica Techniques , Resin Cements/chemistry , Smear Layer , Tooth Preparation , Water/chemistry
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