Tags

Type your tag names separated by a space and hit enter

Marginal quality and fracture strength of root-canal treated mandibular molars with overlay restorations after thermocycling and mechanical loading.
J Adhes Dent. 2010 Aug; 12(4):287-94.JA

Abstract

PURPOSE

To evaluate marginal quality, fracture modes, and loads-to-failure of different overlay restorations in rootcanal treated molars in a laboratory setup.

MATERIALS AND METHODS

Thirty-two mandibular first molars were randomly assigned to four groups (n = 8): UTR= untreated (control), RCT-COM= root canal treated (RCT)+ lab-made composite overlay, RCT-FRC= RCT+composite resin overlay with two layers of multidirectional woven glass fibers; RCT-CER: RCT+ceramic overlay. The teeth in all groups were subjected to thermocycling and mechanical loading (TCML) in a computer-controlled masticator (1,200,000 loads, 49 N, 1.7 Hz, 3000 temperature cycles of 5°C to 50°C). Marginal adaptation was evaluated before and after TCML with scanning electron microscopy at 200X at the tooth-to-luting composite (IF1) and luting composite-to restoration (IF2) interfaces. After TCML, all specimens were loaded to failure in a universal testing machine at 0.5 mm/min. Data were analyzed with ANOVA and Bonferroni correction.

RESULTS

Marginal adaptation decreased from 93 ± 3.4 to 82 ± 6.5 % at IF1 after TCML (p > 0.001) but the decrease was not significant between the groups (p = 0.8130). At IF2, ceramic overlays showed about 10% lower marginal adaptation than composite overlays (p < 0.0001). Loads-to-failure (in N) were as follows in descending order: RCT-FRC: 3619 ± 520; UTR: 3048 ± 905; RCT-COM: 2770 ± 457; RCT-CER 2036 ± 319. RCT-FRC showed significantly higher results than those of RCT-COM (p = 0.0077) and RCT-CER (p < 0.0001). Only RCT-CER showed significantly lower results than that of the control (p = 0.0019). While the fractures in the UTR occurred exclusively above the cementoenamel junction (Mode 1 and Mode 2) and were rated reparable, RCT-COM and RCT-CER showed exclusively catastrophic failures in varying modes (nodes 3 to 5). Only in group RCT-FRC, half of the specimens fractured in a reparable fracture mode (modes 1 and 2) with veneering composite delamination from the glass-fiber weaver layer.

CONCLUSION

As cusp-covering overlay restorations in root canal treated molars, composite resin overlays with and without fiber reinforcement performed similar to intact teeth with varying failure types. While intact teeth failed exclusively in reparable modes, all other restorations failed in a catastrophic manner, except half of the fiber reinforced composite group.

Links

Publisher Full Text

Authors+Show Affiliations

Dere M
Clinic of Preventive Dentistry, Periodontology and Cariology, Center for Dental and Oral Medicine, University of Zürich, Switzerland.
Ozcan M
No affiliation info available
Göhring TN
No affiliation info available

MeSH

Analysis of VarianceComposite ResinsDental BondingDental Cavity PreparationDental Marginal AdaptationDental PorcelainDental Restoration FailureDental Stress AnalysisGlassHumansInlaysMasticationMaterials TestingMolarStatistics, NonparametricTooth CrownTooth FracturesTooth, Nonvital

Pub Type(s)

Journal Article

Language

eng

PubMed ID

20157656

Citation

Dere, Mustafa, et al. "Marginal Quality and Fracture Strength of Root-canal Treated Mandibular Molars With Overlay Restorations After Thermocycling and Mechanical Loading." The Journal of Adhesive Dentistry, vol. 12, no. 4, 2010, pp. 287-94.
Dere M, Ozcan M, Göhring TN. Marginal quality and fracture strength of root-canal treated mandibular molars with overlay restorations after thermocycling and mechanical loading. J Adhes Dent. 2010;12(4):287-94.
Dere, M., Ozcan, M., & Göhring, T. N. (2010). Marginal quality and fracture strength of root-canal treated mandibular molars with overlay restorations after thermocycling and mechanical loading. The Journal of Adhesive Dentistry, 12(4), 287-94. https://doi.org/10.3290/j.jad.a17711
Dere M, Ozcan M, Göhring TN. Marginal Quality and Fracture Strength of Root-canal Treated Mandibular Molars With Overlay Restorations After Thermocycling and Mechanical Loading. J Adhes Dent. 2010;12(4):287-94. PubMed PMID: 20157656.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Marginal quality and fracture strength of root-canal treated mandibular molars with overlay restorations after thermocycling and mechanical loading. AU - Dere,Mustafa, AU - Ozcan,Mutlu, AU - Göhring,Till N, PY - 2010/2/17/entrez PY - 2010/2/17/pubmed PY - 2010/10/6/medline SP - 287 EP - 94 JF - The journal of adhesive dentistry JO - J Adhes Dent VL - 12 IS - 4 N2 - PURPOSE: To evaluate marginal quality, fracture modes, and loads-to-failure of different overlay restorations in rootcanal treated molars in a laboratory setup. MATERIALS AND METHODS: Thirty-two mandibular first molars were randomly assigned to four groups (n = 8): UTR= untreated (control), RCT-COM= root canal treated (RCT)+ lab-made composite overlay, RCT-FRC= RCT+composite resin overlay with two layers of multidirectional woven glass fibers; RCT-CER: RCT+ceramic overlay. The teeth in all groups were subjected to thermocycling and mechanical loading (TCML) in a computer-controlled masticator (1,200,000 loads, 49 N, 1.7 Hz, 3000 temperature cycles of 5°C to 50°C). Marginal adaptation was evaluated before and after TCML with scanning electron microscopy at 200X at the tooth-to-luting composite (IF1) and luting composite-to restoration (IF2) interfaces. After TCML, all specimens were loaded to failure in a universal testing machine at 0.5 mm/min. Data were analyzed with ANOVA and Bonferroni correction. RESULTS: Marginal adaptation decreased from 93 ± 3.4 to 82 ± 6.5 % at IF1 after TCML (p > 0.001) but the decrease was not significant between the groups (p = 0.8130). At IF2, ceramic overlays showed about 10% lower marginal adaptation than composite overlays (p < 0.0001). Loads-to-failure (in N) were as follows in descending order: RCT-FRC: 3619 ± 520; UTR: 3048 ± 905; RCT-COM: 2770 ± 457; RCT-CER 2036 ± 319. RCT-FRC showed significantly higher results than those of RCT-COM (p = 0.0077) and RCT-CER (p < 0.0001). Only RCT-CER showed significantly lower results than that of the control (p = 0.0019). While the fractures in the UTR occurred exclusively above the cementoenamel junction (Mode 1 and Mode 2) and were rated reparable, RCT-COM and RCT-CER showed exclusively catastrophic failures in varying modes (nodes 3 to 5). Only in group RCT-FRC, half of the specimens fractured in a reparable fracture mode (modes 1 and 2) with veneering composite delamination from the glass-fiber weaver layer. CONCLUSION: As cusp-covering overlay restorations in root canal treated molars, composite resin overlays with and without fiber reinforcement performed similar to intact teeth with varying failure types. While intact teeth failed exclusively in reparable modes, all other restorations failed in a catastrophic manner, except half of the fiber reinforced composite group. SN - 1461-5185 UR - https://www.unboundmedicine.com/medline/citation/20157656/Marginal_quality_and_fracture_strength_of_root_canal_treated_mandibular_molars_with_overlay_restorations_after_thermocycling_and_mechanical_loading_ L2 - https://www.quintessence-publishing.com/deu/en/article/842856 DB - PRIME DP - Unbound Medicine ER -