(PRWEB) February 17, 2011
Latest systematic review results suggest high-viscosity glass-ionomer cement (GIC) as safe and economical long-term tooth restorative system in conventional stress bearing Class I and in non-stress bearing Class II and Class V situation. High-viscosity GIC may also be acceptable in Class II stress bearing situations, as long as the isthmus is less than half of the intercuspal distance as stated in the manufacturer's instruction of use.
Systematic reviews, often including meta-analysis as statistical method, provide the highest form of clinical knowledge in terms of achieving internal validity of results.
One systematic review appraised the current clinical evidence regarding the use of high-viscosity GIC for long-term Class I, II and V tooth restorations placed in permanent teeth . This systematic review included 14 clinical studies, providing a total of 27 separate study results and concluded as follows:
· Most of the 27 results show no significant statistical difference between the success rate of high-viscosity GIC restoration and amalgam for treatment of the same clinical indications
· One of the 27 results show that high-viscosity GIC restorations in posterior class V cavities of permanent teeth had a 28% higher chance to be successful than amalgam after 6.3 years
· Two of the 27 results indicate that high-viscosity GIC restorations in posterior class I cavities of permanent teeth have a 6% higher chance after 2.3 years and a 9% higher chance after 4.3 years of being more successful than amalgam
· One of the 27 results show that high-viscosity GIC restorations in posterior class II cavities of permanent teeth have a 61% higher chance of being rated more successful than amalgam (this result requires further confirmation)
· None of the 27 results indicate high-viscosity GICs being inferior to amalgam in clinic
These results show that high-viscosity GIC is not inferior in comparison to traditional amalgam restorations under similar clinical conditions. In addition, two further systematic reviews revealed the following evidence:
· Tooth margins of single-surface GIC restorations in permanent teeth had significantly less carious lesions after 6 years than on amalgam restorations 
· A significantly higher fluoride release (p<0.05) of GIC than from compomers 
Further advances have revealed that a resin coating over a GIC restoration may increase its fracture toughness  and reduce microleakage . This resin layer may also not completely hinder the fluoride release activated by the GIC and thus its external anti-cariogenic effects within the oral cavity .
The EQUIA Restorative System
One cost-effective restorative system has been developed to include a high-viscosity GIC with a coating component, based on the above evidence. The EQUIA Restorative System, developed by GC Corporation (http://www.gceurope.com ), consists of EQUIA Fil also called Fuji IX GP Extra and EQUIA Coat also called G- Coat Plus. The concept of EQUIA is to combine a high-viscosity GIC (EQUIA Fil or Fuji IX GP Extra) with a highly-filled, light curing varnish (EQUIA Coat or G-Coat Plus). According to GC this integrates the main advantages of the high-viscosity GIC (self-adhesion, bulk application, improved mechanical properties) with a protective barrier in the early maturation phase and an improved surface hardness. When EQUIA Fil is coated with EQUIA Coat (EQUIA System) a marked increase in fracture toughness, flexural strength and flexural fatigue resistance are observed.
The clinical application of EQUIA utilizes all listed clinical merits of a high-viscosity GIC restoration and is based on the evidence that resin coating improves the physical properties of the resultant final restoration. In addition, EQUIA offers patients who are unable to afford composite fillings a cost-effective, mercury-free and aesthetic tooth restoration.
Scientific journal articles for further reading:
1. Systematic review of clinical trials by Mickenautsch et al., Clinical Oral Investigation 2010; v14: pp233-240.
2. Systematic review of clinical trials by Mickenautsch et al., European Journal of Paediatric Dentistry 2009; v10: pp41-46.
3. Systematic review of trials by Oliveira et al., Journal of Minimum Intervention in Dentistry 2010; v3: p23 - abstract 023.
4. Investigation of dental materials by Bagheri et al., American Journal of Dentistry 2010; v23: pp142-146.
5. Investigation of dental materials by Magni et al., Journal of Dentistry 2008; v36: pp885-891.
6. Investigation of dental materials by Mazzaoui et al., Dental Materials 2000; v16: pp166-171.
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