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reopen a tooth with partial excavation of caries, one RCT that compared partial (one-step) to stepwise excavation in permanent molars found higher rates of success in maintaining pulp vitality with partial excavation, suggesting there is no need to reopen the cavity and perform a second excavation.20 Interestingly, two RCTs suggest that restoration without excavation can arrest dental caries so long as a good seal of the final restoration is maintained.22,29 Recommendations: 1. There is evidence from RCTs and systematic reviews that incomplete caries excavation in primary and permanent teeth with normal pulps or reversible pulpitis, either partial (one-step) or stepwise (two-step) excavation, results in fewer pulp exposures and fewer signs and symptoms of pulpal disease than complete excavation. 2. There is evidence from two systematic reviews that the rate of restoration failure in permanent teeth is no higher after incomplete rather than complete caries excavation. 3. There is evidence that partial (one-step) excavation followed by placement of final restoration leads to higher success in maintaining pulp vitality in permanent teeth than stepwise (two-step) excavation. Resin infiltration Resin infiltration is used primarily to arrest the progression of non-cavitated interproximal caries lesions.30,31 The aim of the resin infiltration technique is to allow penetration of a low viscosity resin into the porous lesion body of enamel caries.30 Once polymerized, this resin serves as a barrier to acids and theoretically prevents lesion progression.32 A systematic review and meta-analysis evaluated the effectiveness of enamel infiltration in preventing initial caries progression in proximal surfaces of primary and permanent teeth. This review identified eight studies for inclusion for quantitative analysis.33 Seven of the eight studies found that infiltration was significantly more effective than placebo treatment. The meta-analysis compared 470 teeth in the resin infiltration group and 473 in the control group. Caries progression was seen in 61 of the infiltration group and 185 of the control group. Current American Dental Association clinical practice guidelines for non-restorative treatment for noncavitated interproximal caries lesions conditionally recommends enamel infiltration for treatment of these lesions, (low to very low certainty).34 Few RCTs evaluate the long-term effectiveness of resin infiltration, and further research is recommended. An additional use of resin infiltration has been suggested to restore white spot lesions formed during orthodontic treatment. Based on a RCT, resin infiltration significantly improved the clinical appearance of such white spot lesions and visually reduced their size.35,36 Recommendation: 1. There is low to moderate evidence in favor of resin infiltration as a treatment option for small, non-cavitated interproximal caries lesions in primary and permanent teeth. 2. Further research regarding long-term effectiveness of resin infiltration is needed. BEST PRACTICES: RESTORATIVE DENTISTRY 342 THE REFERENCE MANUAL OF PEDIATRIC DENTISTRY Dental amalgam Dental amalgam has been the most commonly used restorative material in posterior teeth for over 150 years.37 Amalgam contains a mixture of metals such as silver, copper, and tin, in addition to approximately 50 percent mercury.38 Dental amalgam has declined in use over the past decade,37 perhaps due to the controversy surrounding perceived health effects of mercury vapor, environmental concerns from its mercury content, and increased demand for esthetic alternatives. With regard to safety of dental amalgam, a comprehensive literature review of dental studies published between 2004 and 2008 found insufficient evidence of associations between mercury release from dental amalgam and the various medical complaints.39 Two independent RCTs in children have examined the effects of mercury release from amalgam restorations and found no effect on the central and peripheral nervous systems and kidney function.40,41 However, on July 28, 2009, the U.S. Food and Drug Administration (FDA) issued a final rule that reclassified dental amalgam to a Class II device (having some risk) and designated guidance that