Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability

In 1995, the Swedish government recommended the discontinuation of amalgam as restorative in paediatric dentistry. Because the mercury content in amalgam constitutes an environmental hazard, its use has declined. The use of resin composites is increasing, but the polymerisation shrinkage of the mate...

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Main Author: Sunnegårdh-Grönberg, Karin
Format: Doctoral Thesis
Language:English
Published: Umeå universitet, Tandhygienistprogrammet 2004
Subjects:
SEM
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-270
http://nbn-resolving.de/urn:isbn:91-7305-589-1
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spelling ndltd-UPSALLA1-oai-DiVA.org-umu-2702013-01-08T13:06:31ZCalcium aluminate cement as dental restorative : Mechanical properties and clinical durabilityengSunnegårdh-Grönberg, KarinUmeå universitet, TandhygienistprogrammetUmeå : Umeå universitet. Institutionen för odontologi2004mechanical propertiesclinicalrestorationsceramiccementresin compositeadaptationSEMIn 1995, the Swedish government recommended the discontinuation of amalgam as restorative in paediatric dentistry. Because the mercury content in amalgam constitutes an environmental hazard, its use has declined. The use of resin composites is increasing, but the polymerisation shrinkage of the material is still undesirably high, and the handling of uncured resin can cause contact dermatitis. A new restorative material has recently been developed in Sweden as an alternative to amalgam and resin composite: a calcium aluminate cement (CAC). CAC has been marketed as a ceramic direct restorative for posterior restorations (class I, II) and for class V restorations. This thesis evaluates mechanical properties and clinical durability of the calcium aluminate cement when used for class II restorations. Hardness, in vitro wear, flexural strength, flexural modulus, and surface roughness were evaluated. A scanning electron replica method was used for evaluation of the interfacial adaptation to tooth structures in vivo. The durability was studied in a 2-year intra-individually clinical follow-up of class II restorations. Major results and conclusions from the studies are as follows: • The CAC was a relatively hard material, harder than resin-modified glass ionomer cement but within the range of resin composites. The CAC wore less than resin-modified glass ionomer cement but more than resin composite. • Flexural strength of CAC was in the same range as that of zinc phosphate cement and far below that of both resin composite and resin-modified glass ionomer cement. Flexural modulus of CAC was higher than both resin composite and resin-modified glass ionomer cement. The low flexural strength of CAC precludes its use in stress-bearing areas. • Surface roughness of CAC could be decreased by several polishing techniques. • For CAC restorations, interfacial adaptation was higher to dentin but lower to enamel compared with resin composite restorations. Fractures were found perpendicular to the boarders of all CAC restorations and may indicate expansion of the material. • After 2 years of clinical service, the class II CAC restorations showed an unacceptably high failure rate. Material fractures and tooth fractures were the main reasons for failure. Doctoral thesis, comprehensive summaryinfo:eu-repo/semantics/doctoralThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-270urn:isbn:91-7305-589-1Umeå University odontological dissertations, 0345-7532 ; 84application/pdfinfo:eu-repo/semantics/openAccess
collection NDLTD
language English
format Doctoral Thesis
sources NDLTD
topic mechanical properties
clinical
restorations
ceramic
cement
resin composite
adaptation
SEM
spellingShingle mechanical properties
clinical
restorations
ceramic
cement
resin composite
adaptation
SEM
Sunnegårdh-Grönberg, Karin
Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability
description In 1995, the Swedish government recommended the discontinuation of amalgam as restorative in paediatric dentistry. Because the mercury content in amalgam constitutes an environmental hazard, its use has declined. The use of resin composites is increasing, but the polymerisation shrinkage of the material is still undesirably high, and the handling of uncured resin can cause contact dermatitis. A new restorative material has recently been developed in Sweden as an alternative to amalgam and resin composite: a calcium aluminate cement (CAC). CAC has been marketed as a ceramic direct restorative for posterior restorations (class I, II) and for class V restorations. This thesis evaluates mechanical properties and clinical durability of the calcium aluminate cement when used for class II restorations. Hardness, in vitro wear, flexural strength, flexural modulus, and surface roughness were evaluated. A scanning electron replica method was used for evaluation of the interfacial adaptation to tooth structures in vivo. The durability was studied in a 2-year intra-individually clinical follow-up of class II restorations. Major results and conclusions from the studies are as follows: • The CAC was a relatively hard material, harder than resin-modified glass ionomer cement but within the range of resin composites. The CAC wore less than resin-modified glass ionomer cement but more than resin composite. • Flexural strength of CAC was in the same range as that of zinc phosphate cement and far below that of both resin composite and resin-modified glass ionomer cement. Flexural modulus of CAC was higher than both resin composite and resin-modified glass ionomer cement. The low flexural strength of CAC precludes its use in stress-bearing areas. • Surface roughness of CAC could be decreased by several polishing techniques. • For CAC restorations, interfacial adaptation was higher to dentin but lower to enamel compared with resin composite restorations. Fractures were found perpendicular to the boarders of all CAC restorations and may indicate expansion of the material. • After 2 years of clinical service, the class II CAC restorations showed an unacceptably high failure rate. Material fractures and tooth fractures were the main reasons for failure.
author Sunnegårdh-Grönberg, Karin
author_facet Sunnegårdh-Grönberg, Karin
author_sort Sunnegårdh-Grönberg, Karin
title Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability
title_short Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability
title_full Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability
title_fullStr Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability
title_full_unstemmed Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability
title_sort calcium aluminate cement as dental restorative : mechanical properties and clinical durability
publisher Umeå universitet, Tandhygienistprogrammet
publishDate 2004
url http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-270
http://nbn-resolving.de/urn:isbn:91-7305-589-1
work_keys_str_mv AT sunnegardhgronbergkarin calciumaluminatecementasdentalrestorativemechanicalpropertiesandclinicaldurability
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