Objective: The present review systematically analyzed clinical studies investigating the efficacy of resin infiltration on post-orthodontic or non-post-orthodontic, white spot lesions (WSL), or fluorosis.Five electronic databases (Central, PubMed, Ovid MEDLINE, Ovid EMBASE, LILACS) were screened. Article selection and data abstraction were done in duplicate. No language or time restrictions were applied. Outcomes were visual-tactile or DIAGNOdent measurements.Eleven studies with 1834 teeth being affected in 413 patients were included. Nine studies were randomized control trials, one a prospective cohort study, and one had an unclear study design. Meta-analysis could be performed for “resin infiltration vs. untreated control,” “resin infiltration vs. fluoride varnish,” and “resin infiltration without bleaching vs. resin infiltration with bleaching.” WSL being treated with resin infiltration showed a significantly higher optical improvement than WSL without any treatment (standard mean difference (SMD) [95% CI] = 1.24 [0.59, 1.88], moderate level of evidence [visual-tactile assessment]) and with fluoride varnish application (mean difference (MD) [95% CI] = 4.76 [0.74, 8.78], moderate level of evidence [DIAGNOdent reading]). In patients with fluorosis, bleaching prior to resin infiltration showed no difference in the masking effect compared to infiltration alone (MD [95% CI] = − 0.30 [− 0.98, 0.39], moderate level of evidence).Resin infiltration has a significantly higher masking effect than natural remineralization or regular application of fluoride varnishes. However, although the evidence was graded as moderate, this conclusion is based on only very few well-conducted RCTs.Resin infiltration seems to be a viable option to esthetically mask enamel white spot lesions and fluorosis.Materials: The present review systematically analyzed clinical studies investigating the efficacy of resin infiltration on post-orthodontic or non-post-orthodontic, white spot lesions (WSL), or fluorosis.Five electronic databases (Central, PubMed, Ovid MEDLINE, Ovid EMBASE, LILACS) were screened. Article selection and data abstraction were done in duplicate. No language or time restrictions were applied. Outcomes were visual-tactile or DIAGNOdent measurements.Eleven studies with 1834 teeth being affected in 413 patients were included. Nine studies were randomized control trials, one a prospective cohort study, and one had an unclear study design. Meta-analysis could be performed for “resin infiltration vs. untreated control,” “resin infiltration vs. fluoride varnish,” and “resin infiltration without bleaching vs. resin infiltration with bleaching.” WSL being treated with resin infiltration showed a significantly higher optical improvement than WSL without any treatment (standard mean difference (SMD) [95% CI] = 1.24 [0.59, 1.88], moderate level of evidence [visual-tactile assessment]) and with fluoride varnish application (mean difference (MD) [95% CI] = 4.76 [0.74, 8.78], moderate level of evidence [DIAGNOdent reading]). In patients with fluorosis, bleaching prior to resin infiltration showed no difference in the masking effect compared to infiltration alone (MD [95% CI] = − 0.30 [− 0.98, 0.39], moderate level of evidence).Resin infiltration has a significantly higher masking effect than natural remineralization or regular application of fluoride varnishes. However, although the evidence was graded as moderate, this conclusion is based on only very few well-conducted RCTs.Resin infiltration seems to be a viable option to esthetically mask enamel white spot lesions and fluorosis.Results: The present review systematically analyzed clinical studies investigating the efficacy of resin infiltration on post-orthodontic or non-post-orthodontic, white spot lesions (WSL), or fluorosis.Five electronic databases (Central, PubMed, Ovid MEDLINE, Ovid EMBASE, LILACS) were screened. Article selection and data abstraction were done in duplicate. No language or time restrictions were applied. Outcomes were visual-tactile or DIAGNOdent measurements.Eleven studies with 1834 teeth being affected in 413 patients were included. Nine studies were randomized control trials, one a prospective cohort study, and one had an unclear study design. Meta-analysis could be performed for “resin infiltration vs. untreated control,” “resin infiltration vs. fluoride varnish,” and “resin infiltration without bleaching vs. resin infiltration with bleaching.” WSL being treated with resin infiltration showed a significantly higher optical improvement than WSL without any treatment (standard mean difference (SMD) [95% CI] = 1.24 [0.59, 1.88], moderate level of evidence [visual-tactile assessment]) and with fluoride varnish application (mean difference (MD) [95% CI] = 4.76 [0.74, 8.78], moderate level of evidence [DIAGNOdent reading]). In patients with fluorosis, bleaching prior to resin infiltration showed no difference in the masking effect compared to infiltration alone (MD [95% CI] = − 0.30 [− 0.98, 0.39], moderate level of evidence).Resin infiltration has a significantly higher masking effect than natural remineralization or regular application of fluoride varnishes. However, although the evidence was graded as moderate, this conclusion is based on only very few well-conducted RCTs.Resin infiltration seems to be a viable option to esthetically mask enamel white spot lesions and fluorosis.Conclusion: The present review systematically analyzed clinical studies investigating the efficacy of resin infiltration on post-orthodontic or non-post-orthodontic, white spot lesions (WSL), or fluorosis.Five electronic databases (Central, PubMed, Ovid MEDLINE, Ovid EMBASE, LILACS) were screened. Article selection and data abstraction were done in duplicate. No language or time restrictions were applied. Outcomes were visual-tactile or DIAGNOdent measurements.Eleven studies with 1834 teeth being affected in 413 patients were included. Nine studies were randomized control trials, one a prospective cohort study, and one had an unclear study design. Meta-analysis could be performed for “resin infiltration vs. untreated control,” “resin infiltration vs. fluoride varnish,” and “resin infiltration without bleaching vs. resin infiltration with bleaching.” WSL being treated with resin infiltration showed a significantly higher optical improvement than WSL without any treatment (standard mean difference (SMD) [95% CI] = 1.24 [0.59, 1.88], moderate level of evidence [visual-tactile assessment]) and with fluoride varnish application (mean difference (MD) [95% CI] = 4.76 [0.74, 8.78], moderate level of evidence [DIAGNOdent reading]). In patients with fluorosis, bleaching prior to resin infiltration showed no difference in the masking effect compared to infiltration alone (MD [95% CI] = − 0.30 [− 0.98, 0.39], moderate level of evidence).Resin infiltration has a significantly higher masking effect than natural remineralization or regular application of fluoride varnishes. However, although the evidence was graded as moderate, this conclusion is based on only very few well-conducted RCTs.Resin infiltration seems to be a viable option to esthetically mask enamel white spot lesions and fluorosis.Clinical relevance: The present review systematically analyzed clinical studies investigating the efficacy of resin infiltration on post-orthodontic or non-post-orthodontic, white spot lesions (WSL), or fluorosis.Five electronic databases (Central, PubMed, Ovid MEDLINE, Ovid EMBASE, LILACS) were screened. Article selection and data abstraction were done in duplicate. No language or time restrictions were applied. Outcomes were visual-tactile or DIAGNOdent measurements.Eleven studies with 1834 teeth being affected in 413 patients were included. Nine studies were randomized control trials, one a prospective cohort study, and one had an unclear study design. Meta-analysis could be performed for “resin infiltration vs. untreated control,” “resin infiltration vs. fluoride varnish,” and “resin infiltration without bleaching vs. resin infiltration with bleaching.” WSL being treated with resin infiltration showed a significantly higher optical improvement than WSL without any treatment (standard mean difference (SMD) [95% CI] = 1.24 [0.59, 1.88], moderate level of evidence [visual-tactile assessment]) and with fluoride varnish application (mean difference (MD) [95% CI] = 4.76 [0.74, 8.78], moderate level of evidence [DIAGNOdent reading]). In patients with fluorosis, bleaching prior to resin infiltration showed no difference in the masking effect compared to infiltration alone (MD [95% CI] = − 0.30 [− 0.98, 0.39], moderate level of evidence).Resin infiltration has a significantly higher masking effect than natural remineralization or regular application of fluoride varnishes. However, although the evidence was graded as moderate, this conclusion is based on only very few well-conducted RCTs.Resin infiltration seems to be a viable option to esthetically mask enamel white spot lesions and fluorosis. [ABSTRACT FROM AUTHOR]