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1.
Trials ; 24(1): 807, 2023 Dec 15.
Article En | MEDLINE | ID: mdl-38102685

BACKGROUND: Full pulpotomy has been proposed as an alternative to root canal treatment in teeth with signs and symptoms indicative of irreversible pulpitis (IRP), but the evidence is limited, relying on underpowered studies with a high risk of bias. The aim of this study is to conduct a prospective meta-analysis (PMA) of individual participant data of a series of individual randomised trials to provide robust evidence on the clinical and cost-effectiveness of pulpotomy compared with root canal treatment. METHODS: Individual participant data will be obtained from a series of randomised trials designed and conducted by a consortium of multi-national investigators with an interest in vital pulp treatment. These individualised trials will be conducted using a specified protocol, defined outcomes, and outcome measures. Ten parallel-group randomised trials currently being conducted in 10 countries will provide data from more than 500 participants. The primary outcome is a composite measure defined as (1) the absence of pain indicative of IRP, (2) the absence of signs and symptoms indicative of acute or chronic apical periodontitis, and (3) the absence of radiographic evidence of failure including radiolucency or resorption. Individual participant data will be obtained, assessed, and checked for quality by two independent reviewers prior to the PMA. Pooled estimates on treatment effects will be generated using a 2-stage meta-analysis approach. The first stage involves a standard regression analysis in each trial to produce aggregate data on treatment effect estimates followed by an inverse variance weighted meta-analysis to combine these aggregate data and produce summary statistics and forest plots. Cost-effectiveness analysis based on the composite outcome will be undertaken as a process evaluation to evaluate treatment fidelity and acceptability by patients and dentists. RESULTS: The research question and trial protocol were developed and approved by investigators in all 10 sites. All sites use shared resources including study protocols, data collection forms, participant information leaflets, and consent forms in order to improve flow, consistency, and reproducibility. Each site obtained its own Institutional Review Board approval, and trials were registered in appropriate open access platforms. Patient recruitment has started in most sites, as of July 2023. DISCUSSION: PMA offers a rigorous, flexible, and efficient methodology to answer this important research question and provide results with improved generalisability and external validity compared with traditional trials and retrospective meta-analyses. The results of this study will have implications for both the delivery of clinical practice and structured clinical guidelines' development. TRIAL REGISTRATION: PROSPERO CRD42023446809. Registered on 08 February 2023.


Pulpitis , Humans , Dental Pulp Cavity , Meta-Analysis as Topic , Prospective Studies , Pulpitis/diagnosis , Pulpitis/therapy , Pulpotomy , Randomized Controlled Trials as Topic , Reproducibility of Results , Retrospective Studies , Treatment Outcome
2.
Aust Dent J ; 68 Suppl 1: S110-S122, 2023 Jun.
Article En | MEDLINE | ID: mdl-37986231

Root canal treatment (RCT) has been considered the conventional standard for the management of teeth with carious pulp exposure, particularly in mature teeth presenting with symptoms. Following a better understanding of the histopathology of deep carious lesions, the histology of the cariously exposed pulp and the healing potential of the inflamed pulp, vital pulp therapy (VPT) is increasingly adopted around the world for the management of permanent teeth with clinical signs and symptoms indicative of irreversible pulpitis. Furthermore, VPT became a recognized treatment modality by the European Society of Endodontology (ESE) and the American Association of Endodontists (AAE) by virtue of its high success rates reported in outcome studies using contemporary hydraulic calcium silicate-based cements. However, proper case selection, strict asepsis, capping materials and good coronal seal are mandatory for success. The aim of this paper is to review the biological basis for VPT in symptomatic teeth with carious pulp exposure and to report on the outcome of pulpotomy in teeth with clinical diagnosis of irreversible pulpitis.


Pulpitis , Humans , Pulpitis/drug therapy , Root Canal Therapy , Dental Pulp , Pulpotomy , Dentition, Permanent , Calcium Compounds/therapeutic use , Silicates/therapeutic use , Treatment Outcome
3.
Clin Oral Investig ; 25(1): 311-317, 2021 Jan.
Article En | MEDLINE | ID: mdl-32483680

OBJECTIVES: The purpose of this study was to assess the clinical and radiographic outcome of root-end microsurgery using a premixed fast-set calcium silicate putty as root-end filling material in human teeth. MATERIALS AND METHODS: This study included 50 teeth in 35 patients, whose ages ranged from 16 to 69 years. After clinical and radiographic examination, informed consent was obtained and one resident performed all surgical procedures using an endodontic microsurgical approach. A tricalcium silicate-based putty (TotalFil FS putty, FKG Dentair, La Chaux-de-Fonds, Switzerland) was used as a root-end filling material. Patients were recalled and treated teeth were examined clinically and radiographically at 3 months, 6 months, and 1 year postoperatively. The outcome was determined based on clinical and radiographic results. Radiographic healing was classified into 4 categories: complete, incomplete, uncertain, and unsatisfactory. Analysis of predictors was performed using the Pearson chi-square or Fisher's exact test. RESULTS: At the time of surgery, 3 teeth were diagnosed with cracks and were excluded from the study. The recall rates were 85% at 3 months, 100% at 6 months, and 95% at 1 year. One tooth failed at 3 months, 3 failed at 1 year, with a success rate of 93%. None of the predictors investigated had a significant influence on the outcome of microsurgery. CONCLUSIONS: Premixed fast-set tricalcium silicate putty is a suitable root-end filling material for use in endodontic microsurgery. CLINICAL RELEVANCE: Tricalcium silicate-based cements have shown promising biological properties as a root-end-filling material. Premixed and fast-set formulations achieved high success rates in clinical studies. TRIAL REGISTRATION: Clinicaltrials.gov registration number NCT03733938.


Microsurgery , Root Canal Filling Materials , Adolescent , Adult , Aged , Aluminum Compounds , Calcium Compounds , Drug Combinations , Humans , Middle Aged , Oxides , Prospective Studies , Silicates , Switzerland , Young Adult
4.
Oper Dent ; 44(1): 96-107, 2019.
Article En | MEDLINE | ID: mdl-29953339

OBJECTIVES:: This study compared light transmission through different thicknesses of bulk-fill resin-based composites (RBCs) using a polywave and a single-peak light-emitting diode light-curing unit (LCU). The effect on the surface hardness was also evaluated. METHODS:: Five bulk-fill RBCs were tested. Specimens (n=5) of 1-, 2-, 4-, or 6-mm thickness were photopolymerized for 10 seconds from the top using a polywave (Bluephase Style) or single-peak (Elipar S10) LCU, while a spectrophotometer monitored in real time the transmitted irradiance and radiant exposure reaching the bottom of the specimen. After 24 hours of storage in distilled water at 37°C, the Vickers microhardness (VH) was measured at top and bottom. Results were analyzed using multiple-way analysis of variance, Tukey post hoc tests, and multivariate analysis (α=0.05). RESULTS:: The choice of LCU had no significant effect on the total amount of light transmitted through the five bulk-fill RBCs at each thickness. There was a significant decrease in the amount of light transmitted as the thickness increased for all RBCs tested with both LCUs ( p<0.001). Effect of LCU on VH was minimal (ηp2=0.010). The 1-, 2-, and 4-mm-thick specimens of SDR, X-tra Fill, and Filtek Bulk Restorative achieved a VHbottom/top ratio of approximately 80% when either LCU was used. CONCLUSIONS:: The total amount of light transmitted through the five bulk-fill RBCs was similar at the different thicknesses using either LCU. The polywave LCU used in this study did not enhance the polymerization of the tested bulk-fill RBCs when compared with the single-peak LCU.


Composite Resins/chemistry , Curing Lights, Dental , Light-Curing of Dental Adhesives/methods , Dental Materials/chemistry , Hardness Tests , Materials Testing , Methacrylates , Polymerization , Surface Properties
5.
Oper Dent ; 43(4): E173-E190, 2018.
Article En | MEDLINE | ID: mdl-29570020

The aim of this review was to compile recent evidence related to nanofilled resin composite materials regarding the properties and clinical performance. Special attention was given to mechanical properties, such as strength, hardness, abrasive wear, water sorption, and solubility. The clinical performance of nanocomposite materials compared with hybrid resin composites was also addressed in terms of retention and success rates, marginal adaptation, color match, and surface roughness. A search of English peer-reviewed dental literature (2003-2017) from PubMed and MEDLINE databases was conducted using the terms "nanocomposites" or "nanofilled resin composite" and "clinical evaluation." The list was screened, and 82 papers that were relevant to the objectives of this work were included in the review. Mechanical properties of nanocomposites are generally comparable to those of hybrid composites but higher than microfilled composites. Nanocomposites presented lower abrasive wear than hybrids but higher sorption values. Their clinical performance was comparable to that of hybrid composites.


Composite Resins/chemistry , Dental Materials/chemistry , Dental Restoration Wear , Nanocomposites/chemistry , Color , Compressive Strength , Dental Marginal Adaptation , Dental Restoration Failure , Dental Stress Analysis , Hardness , Materials Testing , Solubility , Surface Properties , Tensile Strength
6.
Int Endod J ; 51(8): 819-828, 2018 Aug.
Article En | MEDLINE | ID: mdl-29397003

AIM: To assess the outcome of full pulpotomy using Biodentine in permanent teeth with carious exposures and symptoms indicative of irreversible pulpitis. METHODOLOGY: Sixty-four permanent molar teeth with symptomatic vital pulps in 52 patients aged 19-69 years were included. Preoperative pulpal and periapical diagnosis was established. After informed consent, the tooth was anaesthetized, isolated using rubber dam and disinfected with 5% NaOCl before caries excavation; subsequently, the pulp was amputated to the level of the canal orifices. Haemostasis was achieved, and a 3-mm layer of Biodentine (Septodont, Saint-Maur-des-Fosses, France) was placed as the pulpotomy agent. Resin-modified glass-ionomer liner was placed and the tooth restored with either resin composite or amalgam, and a postoperative periapical radiograph exposed. Clinical and radiographic evaluation was completed at 6 months and 1 year postoperatively. Pain levels were scored preoperatively and 2 days post-treatment. RESULTS: Clinical signs and symptoms indicative of irreversible pulpitis were established in all teeth, and periapical rarefaction was present in nine teeth. After 2 days, 93.8% reported complete relief of pain. At 6 months, 63 of 64 attended recall with 98.4% clinical and radiographic success. At 1 year, 59 of 63 attended recall, with 100% clinical and 98.4 radiographic success. Seven of eight cases with periapical rarefaction who attended recall had improvement in the periapical index (PAI) score. A hard tissue barrier was detected radiographically in four cases. CONCLUSION: Full pulpotomy using Biodentine was a successful treatment option for cariously exposed pulps in mature permanent molar teeth with clinical signs and symptoms indicative of irreversible pulpitis, up to 1 year.


Calcium Compounds/therapeutic use , Pulpitis/surgery , Pulpotomy , Silicates/therapeutic use , Adult , Aged , Humans , Middle Aged , Treatment Outcome
7.
Article En | WPRIM | ID: wpr-732538

Previous studies explain the time course of withdrawal symptoms among smokers pre and post quit attempt, either withor without the help of medication. Studies showed that male Muslim smokers could quit smoking during Ramadan sincefasting relate to the changes in psychosomatic, daily activities and nicotine withdrawal symptoms. This study aimed toinvestigate the time course of withdrawal symptoms among smokers who used nicotine patch to quit smoking duringfasting in Ramadan. A total of 40 eligible Muslim males who tried to quit smoking was selected and provided with smokingcessation counseling for the duration of 8 to 10 weeks while on nicotine patch. Participants level of withdrawal symptomswas recorded by using nine items of Minnesota Nicotine Withdrawal Scale over a period of 60 days. Participant’s carbonmonoxide reading and body weight were measured within six months including pre and post-Ramadan fasting. Over fourweeks of the fasting month, the measured withdrawal symptoms such as urge to smoke (P ≤ 0.001), depressed mood (P≤ 0.001), irritability/frustration or anger (P ≤ 0.05), anxiety (P ≤ 0.05), difficulty concentrating(P ≤ 0.001), restlessness(P ≤ 0.001), difficulty going to sleep (P ≤ 0.001) and impatient (P ≤ 0.05) significantly decreased except appetite by theend of week 4. Time course analyses demonstrated that all outcome measures showed good effects during cessation infasting month. The point prevalence abstinence at first month of quitting was 67.5% which is higher in fasting month.This has shown positive clinical implications in managing smoking cessation program during Ramadan with the aid ofnicotine patch.

8.
Int Endod J ; 50(11): 1105-1106, 2017 11.
Article En | MEDLINE | ID: mdl-28980725
9.
J Dent ; 63: 60-64, 2017 Aug.
Article En | MEDLINE | ID: mdl-28571830

OBJECTIVES: To evaluate the effect of using a bulk-fill flowable base material on fracture strength and fracture patterns of root-filled maxillary premolars with MOD preparations restored with laminate restorations. METHODS: Fifty extracted maxillary premolars were selected for the study. Standardized MOD cavities with endodontic treatment were prepared for all teeth, except for intact control. The teeth were divided randomly into five groups (n=10); (Group 1) sound teeth, (Group 2) unrestored teeth; (Group 3) MOD cavities with Vitrebond base and resin-based composite (Ceram. X One Universal); (Group 4) MOD cavities with 2mm GIC base (Fuji IX GP) and resin-based composite (Ceram. X One Universal) open laminate, (Group 5) MOD cavities were restored with 4mm of bulk-fill flowable base material (SDR) and resin-based composite (Ceram. X One Universal). All teeth were thermocycled and subjected to a 45° ramped oblique load in a universal testing machine. Fracture load and fracture patterns were recorded. Data were analyzed using one-way ANOVA and Dunnett's T3 test. RESULTS: Restoration in general increased the fracture strength compared to unrestored teeth. The fracture strength of group 5 (bulk-fill) was significantly higher than the fracture strength of the GIC laminate groups and not significantly different from the intact teeth (355±112N, P=0.118). The type of failure was unfavorable for most of the groups, with the majority being mixed failures. CONCLUSIONS: The use of a bulk-fill flowable base material significantly increased the fracture strength of extracted root-filled teeth with MOD cavities; however it did not improve fracture patterns to more favorable ones. CLINICAL SIGNIFICANCE: Investigating restorative techniques that may improve the longevity of root-filled premolar teeth restored with direct resin restorations.


Acrylic Resins/chemistry , Composite Resins/chemistry , Dental Materials/chemistry , Dental Restoration, Permanent , Polyurethanes/chemistry , Root Canal Obturation , Tooth Fractures , Bicuspid/anatomy & histology , Bicuspid/injuries , Dental Cavity Preparation/classification , Dental Cavity Preparation/methods , Dental Restoration, Permanent/classification , Dental Stress Analysis , Glass Ionomer Cements/chemistry , Humans , Materials Testing , Maxilla , Stress, Mechanical , Tooth Root , Tooth, Nonvital/therapy
10.
Oper Dent ; 42(1): E24-E34, 2017.
Article En | MEDLINE | ID: mdl-28002691

This article aims to review the research done on the silorane-based resin composites (SBRC) regarding polymerization shrinkage and contraction stresses and their ability to improve the shortcomings of the methacrylate-based resin composites (MRBC). Special attention is given to their physical and mechanical properties, bond strength, marginal adaptation, and cusp deflection. The clinical significance of this material is critically appraised with a focus on the ability of SBRC to strengthen the tooth structure as a direct restorative material. A search of English peer-reviewed dental literature (2003-2015) from PubMed and MEDLINE databases was conducted with the terms "low shrinkage" and "silorane composites." The list was screened, and 70 articles that were relevant to the objectives of this work were included.


Composite Resins/chemistry , Dental Restoration, Permanent/methods , Silorane Resins/chemistry , Dental Stress Analysis , Evidence-Based Dentistry , Humans , Polymerization
11.
Int Endod J ; 50(2): 117-125, 2017 Feb.
Article En | MEDLINE | ID: mdl-26715408

AIM: To assess the outcome of mineral trioxide aggregate (MTA) complete pulpotomy in permanent teeth with carious exposures. METHODOLOGY: Fifty-two permanent molar teeth with fully developed roots and vital pulps in 43 patients aged 11-51 years were included. Preoperative pulpal and periapical diagnosis was established. After informed consent, each tooth was anaesthetized, isolated with dental dam and disinfected with 5% NaOCl before caries excavation; subsequently, a full pulpotomy was performed. Haemostasis was achieved, and Grey MTA (Angelus, Londrina, Brazil) was placed as the pulpotomy agent; a moist cotton pellet was placed, and the tooth was temporized with the intermediate restorative material (IRM). Permanent restorations were placed 1 week later if the tooth was asymptomatic, and a postoperative periapical radiograph was taken. Clinical and radiographic evaluation was completed at 3 months, 6 months, 1 year and 3 years postoperatively. RESULTS: Clinical signs and symptoms suggestive of irreversible pulpitis were established in 44/52 teeth, and periapical rarefaction was present in 14 teeth. Immediate failure occurred in one tooth. The recall rate ranged from 92% at 3 months to 80.3% at 3 years, with an overall 100% clinical and 97.5% radiographic success during the first year, and 92.7% success at 3 years. All cases with periapical rarefaction were associated with improvement in the periapical index (PAI) score. Two cases had new periapical rarefaction associated with dislodgment of the permanent restoration. A hard tissue barrier was detected radiographically in 5 cases and canal narrowing in 7 cases. CONCLUSION: MTA full pulpotomy was a successful treatment option for cariously exposed pulps in mature permanent molar teeth.


Aluminum Compounds , Calcium Compounds , Dental Caries/surgery , Oxides , Pulpotomy/methods , Silicates , Adolescent , Adult , Child , Drug Combinations , Humans , Middle Aged
12.
J Dent ; 43(6): 735-41, 2015 Jun.
Article En | MEDLINE | ID: mdl-25656772

OBJECTIVES: To compare fracture characteristics of root-filled teeth with variable cavity design restored with a low shrinkage silorane and methacrylate-based resin composite. METHODS: 77 extracted maxillary premolars were divided randomly into seven groups: (Group 1) intact teeth; (Groups 2-4) MOD plus endodontic access with the buccopalatal width of the occlusal isthmus equals one third of the intercuspal width; (Groups 5-7) MOD plus endodontic access with the buccopalatal width of the occlusal isthmus equals one half of the intercuspal width. Groups 2 and 5 were left unrestored, Groups 3 and 6 were restored with a silorane-based resin composite (Filtek P90) and Groups 4 and 7 with a methacrylate-based resin composite (Z250). Teeth were loaded in a universal testing machine; load and fracture patterns were recorded and compared statistically using 2-way ANOVA and t-test for pairwise comparisons and 1-way ANOVA with Dunnett test for multiple comparisons. RESULTS: Unrestored teeth became progressively weaker with more extensive preparations, Group 5 (unfilled ½) showed the lowest fracture load among the groups (71±22N, P<0.001). Restorations increased the fracture strength of unrestored teeth regardless of cavity size (P<0.001), but was still significantly weaker than sound teeth, with no significant difference between silorane and methacrylate groups. Failure of restored teeth was mostly adhesive at the tooth restoration interface. CONCLUSIONS: Silorane-based resin composite have no superior strengthening effect over the conventional methacrylate-based resin composite in restoration of root filled teeth. Both materials showed similar fracture patterns. CLINICAL SIGNIFICANCE: Root filled teeth are considerably weakened via restorative and endodontic procedures. A direct adhesive restoration will aid in preserving tooth structure as far as it provides enough strength.


Bicuspid/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Composite Resins/chemistry , Methacrylates/chemistry , Root Canal Filling Materials/chemistry , Silorane Resins/chemistry , Tooth Fractures/prevention & control , Tooth Root/chemistry , Bicuspid/injuries , Dental Restoration, Permanent/methods , Dental Stress Analysis , Humans , Random Allocation , Root Canal Obturation/methods
13.
Oper Dent ; 39(2): 181-8, 2014.
Article En | MEDLINE | ID: mdl-23848066

AIM: To assess fracture strength and fracture patterns of root-filled teeth with direct resin composite restorations under static and fatigue loading. METHODOLOGY: MOD cavities plus endodontic access were prepared in 48 premolars. Teeth were root filled and divided into three restorative groups, as follows 1) resin composite; 2) glass ionomer cement (GIC) core and resin composite; and 3) open laminate technique with GIC and resin composite. Teeth were loaded in a servohydraulic material test system. Eight samples in each group were subjected to stepped fatigue loading: a preconditioning load of 100 N (5000 cycles) followed by 30,000 cycles each at 200 N and higher loads in 50-N increments until fracture. Noncycled teeth were subjected to a ramped load. Fracture load, number of cycles, and fracture patterns were recorded. Data were analyzed using two-way analysis of variance and Bonferroni tests. RESULTS: Fatigue cycling reduced fracture strength significantly (p<0.001). Teeth restored with a GIC core and a laminate technique were significantly weaker than the composite group (379±56 N, 352±67 N vs 490±78 N, p=0.001). Initial debonding occurred before the tooth underwent fracture. All failures were predominantly adhesive, with subcrestal fracture of the buccal cusp. CONCLUSIONS: Resin composite restorations had significantly higher fracture strength than did other restorations. Fatigue cycled teeth failed at lower load than did noncycled teeth.


Composite Resins/therapeutic use , Dental Restoration, Permanent , Root Canal Obturation , Tooth Fractures/etiology , Bicuspid/surgery , Dental Restoration, Permanent/adverse effects , Dental Restoration, Permanent/methods , Dental Stress Analysis , Humans , Root Canal Obturation/adverse effects , Root Canal Obturation/methods
14.
Aust Dent J ; 58(4): 448-53, 2013 Dec.
Article En | MEDLINE | ID: mdl-24320901

BACKGROUND: Although various mechanical properties of tooth-coloured materials have been described, little data have been published on the effect of ageing and G-Coat Plus on the hardness and strength of the glass-ionomer cements (GICs). METHODS: Specimens were prepared from one polyacid-modified resin composite (PAMRC; Freedom, SDI), one resin-modified glass-ionomer cement; (RM-GIC; Fuji II LC, GC), and one conventional glass-ionomer cement; (GIC; Fuji IX, GC). GIC and RM-GIC were tested both with and without applying G-Coat Plus (GC). Specimens were conditioned in 37 °C distilled water for either 24 hours, four and eight weeks. Half the specimens were subjected to a shear punch test using a universal testing machine; the remaining half was subjected to Vickers Hardness test. RESULTS: Data analysis showed that the hardness and shear punch values were material dependent. The hardness and shear punch of the PAMRC was the highest and GIC the lowest. Applying the G-Coat Plus was associated with a significant decrease in the hardness of the materials but increase in the shear punch strength after four and eight weeks. CONCLUSIONS: The mechanical properties of the restorative materials were affected by applying G-Coat Plus and distilled water immersion over time. The PAMRC was significantly stronger and harder than the RM-GIC or GIC.


Compomers , Glass Ionomer Cements , Materials Testing/methods , Dental Materials , Hardness , Humans , Immersion , Resins, Synthetic , Shear Strength , Time Factors , Water
15.
J Dent ; 40(8): 617-23, 2012 Aug.
Article En | MEDLINE | ID: mdl-22521705

OBJECTIVE: To evaluate the open laminate technique using glass ionomer cements (GIC) in association with a low shrink composite for restoring root filled premolars. METHODS: Extensive MOD cavities plus endodontic access and root filling were performed in intact extracted maxillary premolars. Three restoration types were evaluated: (1) resin composite alone; (2) resin-modified GIC (RM-GIC) open laminate plus resin composite; (3) conventional GIC open laminate plus resin composite (n=8 for all groups and tests). Three tests were conducted to assess restorations: (A) inward cusp deflection during light curing, using DCDTs; (B) fracture strength using a ramped oblique load at 45° to the long axis in a servohydraulic testing machine in comparison with intact and unrestored teeth; (C) proximal marginal leakage using methylene blue dye and the effect of thermocycling. Data were analysed using 1-way ANOVA for cuspal deflection and fracture strength and Fisher's exact test for leakage. RESULTS: Laminate restorations resulted in significantly less cuspal deflection compared with resin composite (4.2±1.2 µm for RM-GIC and 5.1±2.3 µm for conventional GIC vs. 12.2±2.6 µm for composite, P<0.001). Fracture strength was not significantly different among all groups. Failure with all restorations was predominantly adhesive at the tooth-restoration interface. The two laminate groups showed significantly better marginal seal than composite alone, but sealing ability of conventional GIC deteriorated after thermocycling. CONCLUSIONS: Laminate restoration of root filled teeth had beneficial effects in terms of reducing cuspal deflection and marginal seal, with acceptable fracture strength.


Composite Resins/chemistry , Dental Materials/chemistry , Dental Restoration, Permanent/methods , Glass Ionomer Cements/chemistry , Acid Etching, Dental/methods , Adhesiveness , Bicuspid/pathology , Bisphenol A-Glycidyl Methacrylate/chemistry , Coloring Agents , Dental Cavity Preparation/methods , Dental Leakage/classification , Dental Restoration Failure , Dental Stress Analysis/instrumentation , Humans , Light-Curing of Dental Adhesives , Materials Testing , Methylene Blue , Phosphoric Acids/chemistry , Polymerization , Resin Cements/chemistry , Resins, Synthetic/chemistry , Root Canal Preparation/methods , Stress, Mechanical , Temperature , Tooth Crown/pathology , Tooth, Nonvital/therapy
16.
J Dent ; 39(8): 527-35, 2011 Aug.
Article En | MEDLINE | ID: mdl-21620926

OBJECTIVE: To compare fracture characteristics of root-filled teeth with variable cavity design and resin composite restoration. METHODS: 80 extracted intact maxillary premolars were divided randomly into eight groups; (1) intact teeth; (2) unrestored MOD cavity; (3) unrestored MOD cavity plus endodontic access through the occlusal floor; (4) unrestored MOD plus endodontic access with axial walls removed; (5) MOD restored with resin composite; (6) MOD plus endodontic access, resin composite; (7) MOD plus extensive endodontic access, resin composite; (8) MOD plus extensive endodontic access, GIC core and resin composite. A ramped oblique load was applied to the buccal cusp in a servohydraulic testing machine. Fracture load and fracture patterns were recorded. Fracture loads were compared statistically using 1-way ANOVA, with Dunnett test for multiple comparisons. RESULTS: Unrestored teeth became progressively weaker with more extensive preparations. Endodontic access confined within the occlusal floor did not significantly affect strength compared to an MOD cavity. Loss of axial walls weakened teeth considerably [292+80N vs 747+130N for intact teeth]. Restoration increased the strength of prepared teeth particularly in teeth without axial walls. Teeth with a GIC core were not significantly weaker than intact teeth [560+167N]. Failures were mostly adhesive at the buccal interface, with the fracture propagating from the buccal line angle of the occlusal floor (MOD and MOD plus access groups) or of the proximal box (axial wall removed). CONCLUSIONS: Direct restorations increased fracture resistance of root filled teeth with extensive endodontic access. Both restored and unrestored teeth showed similar fracture patterns.


Composite Resins/chemistry , Dental Materials/chemistry , Dental Restoration, Permanent , Root Canal Therapy , Tooth Fractures/physiopathology , Acid Etching, Dental/methods , Acrylic Resins/chemistry , Bicuspid/anatomy & histology , Bicuspid/injuries , Bisphenol A-Glycidyl Methacrylate/chemistry , Dental Cavity Preparation/classification , Dental Restoration, Permanent/classification , Dental Stress Analysis/instrumentation , Dentin/anatomy & histology , Dentin/injuries , Dentin-Bonding Agents/chemistry , Epoxy Resins/chemistry , Glass Ionomer Cements/chemistry , Gutta-Percha/chemistry , Humans , Materials Testing , Post and Core Technique , Root Canal Filling Materials/chemistry , Root Canal Preparation/classification , Stress, Mechanical , Tooth Cervix/anatomy & histology , Tooth Crown/anatomy & histology , Tooth Crown/injuries
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