Table 2 Studies excluded from the final review, with reasons for exclusion

Andersson et al. [22] 2007

Effect of a dental cream containing amorphous calcium phosphate complexes on white spot lesion regression assessed by laser fluorescence.

Product used - a CPP-ACP dental crème which is difficult to obtain or no longer available commercially.

Robertson et al.[23] 2011

MI Paste Plus® to prevent demineralisation in orthodontic patients. A prospective randomised controlled trial.

Product delivery – did not follow the recommended usage instructions for the product.

Participants wore customised intra-oral trays containing MI Paste Plus® for a minimum of 3–5 mins per day.

Kitasako et al.[24] 2010

The clinical application of surface pH measurements to longitudinally assess white spot enamel lesions.

Outcome measure - surface pH of enamel.

Marchisio et al.[25] 2010

Salivary pH level and bacterial plaque evaluation in orthodontic patients treated with Recaldent® products.

Outcome measure - salivary and plaque pH.

Thepyou et al. [26] 2013

Casein phophopeptide-amorphous calcium phosphate and glass ionomer show distinct effects in the remineralization of proximal artificial caries lesion in situ.

Test specimens - artificial caries lesions.

Caruana et al. [27] 2009

The effect of casein and calcium containing paste on plaque pH following a subsequent carbohydrate challenge.

Outcome measure - plaque pH.

Ferrazzano et al. [28] 2011

In vivo remineralising effect of GC Tooth Mousse® on early dental enamel lesion: SEM analysis.

Test specimens – artificially demineralised enamel.

Baroni et al. [29] 2014

A SEM and non-contact surface white light profilometry in vivo study of the effect of a crème containing CPP-ACP and fluoride on young etched enamel.

Outcome measure - incisor surface morphology using scanning electron microscope and white light profilometry following etching with 37 % phosphoric acid.