In vivo analysis of traditional amalgam restorations Traditionally, carious dentin may be removed ness, GIC liner, and cavity varnish under amalgam mechanically with burs or hand excavators, and fillings. Thus, the aim of this study was to evalu- caries indicator dyes were developed to make op- ate in vivo the occurrence of secondary caries erative caries removal a more objective.6,7 Since and dentin characteristics in permanent molars the use of diamond and tungsten carbide burs by means of visual examination, radiographs and could result in indiscriminate caries removal, laser fluorescence (DIAGNOdent) after restor- caries-infected and caries-affected dentin can ing teeth using these clinical steps: hand caries be removed simultaneously, with possible exten- removal, indirect pulp capping with GIC, applying sion into the underlying sound dentin.2 Moreover, copal varnish and filling the cavity with amalgam. evidence shows that there is a significant risk of The hypothesis tested was that the above men- over-extensive clinical cavity preparation by using tioned protocol would product satisfactory results a caries indicator during caries removal.8 Thus, at the 12-month follow-up period. both methods using burs or caries indicator dyes for caries excavation are not clinically encouraged MATERIAL AND METHODS given that they are contrary to the minimal inter- Ethical Considerations vention approach to dentistry. The project was approved by the Research Eth- Instead, manual carious dentin removal with ics Committee of the local institution. All patients sharp hand instruments, without using caries in- or their parents/guardians received information dicator dyes may be encouraged, because heavily about the study and signed a free informed term infected soft and necrotic dentin must be removed of consent in accordance with Resolution 196/6 of before placing a restoration.9 This method is still the National Health Council and the Declaration of controversial since there is difficulty in detecting Helsinki (2000). infected, carious dentin accurately and reliably by visual and tactile clinical examination.10,11 How- Experimental design ever, it has been demonstrated that even without The factor under study in this prospective con- completely removing the infected dentin, the filled trolled clinical trial was the clinical protocol of tooth did not show caries progression.12,13 Thus, amalgam filling after manual caries removal ac- the infected dentin that possibly remained after cording to hardness, indirect pulp capping with GIC mechanical caries removal by hand could not have and cavity varnish application. The response vari- influenced caries progression. So, it is important ables were: (1) mineral content of dentin before to evaluate the tooth response after removing den- and after cavity preparation and after a 12-month tin caries by hardness criteria, since manual car- period of observation; (2) dentin color after cav- ies removal using sharp hand instruments with- ity preparation and after 12 months; (3) recurrent out caries indicator dyes would preserve a larger caries attack after 12 months by radiographic ex- amount of dentinal tissue. Furthermore, the place- amination; (4) presence of active soft carious den- ment of liners with cariostatic behavior, especially tin after 12 months by visual analysis; (5) thickness due to fluoride release, such as GIC on dentin after of dentin between the pulp and the GIC liner after manual caries removal, could increase resistance baseline restoration and after 12 months by radio- to subsequent acid challenge.14 graphic examination. Materials used in this study After GIC liner placement, a cavity varnish ap- are listed in Table 1. plication was traditionally indicated in order to re- duce microleakage.15 In vitro studies have contra- Study population indicated the clinical use of cavity varnish since it The sample consisted of 30 high caries-risk increases marginal microleakage, which is related volunteers (chosen according to the Thompson to secondary caries.16,17 Nevertheless, laboratory and Kaim18 criteria) in the 7 to14 year-old age studies are limited and do not reproduce the oral group who had not used any antibiotics during the environment. period of 2 months prior to the study; whose teeth Long-term in vivo follow-up investigations are were examined and 30 of their permanent molars needed in an endeavor to evaluate dentinal reac- were selected for inclusion in the study. Inclusion tion to manual caries removal according to hard- criteria were: (1) teeth presenting cavitated caries 264 European Journal of Dentistry