Association Between Patient Age and Color Change, Tooth Sensitivity, and Patient-Reported Outcomes of Dental Bleaching: A Systematic Review

Background/Objectives: Dental bleaching outcomes may vary according to patient-related factors. Age-related changes in dental tissues may influence bleaching efficacy, adverse effects, and patient-reported outcomes. This systematic review evaluated the influence of patient age on outcomes of vital tooth bleaching. Methods: The review followed PRISMA 2020 guidelines and was registered in PROSPERO (CRD420261473683). PubMed/MEDLINE, Embase, Cochrane Library, Scopus, LILACS, and OpenGrey were searched without date or language restrictions. Clinical studies assessing bleaching outcomes according to age were included. The primary outcome was color change; secondary outcomes included tooth sensitivity, gingival irritation, and patient-reported outcomes. Risk of bias was assessed using RoB 2 and ROBINS-I, and certainty of evidence using GRADE. Because of clinical and methodological heterogeneity among the included studies, a meta-analysis was not feasible, and the findings were synthesized narratively. Results: Four studies involving 296 participants were included. Three reported greater color change in younger individuals in at least one protocol, whereas one found no age-related differences. Differences favoring younger participants were more frequent after in-office bleaching, while at-home bleaching with 10% carbamide peroxide showed comparable outcomes among age groups. Tooth sensitivity findings were inconsistent: three studies found no significant age-related differences, while one reported greater sensitivity in younger individuals. One study reported greater gingival irritation in younger participants, whereas oral health-related quality of life and most measures of esthetic self-perception did not differ between age groups. Certainty of evidence was very low for color change and tooth sensitivity. Conclusions: The available evidence suggests that age-related differences in bleaching-related color change may vary according to the bleaching protocol, with greater color change in younger individuals more consistently reported following in-office bleaching. However, the very low certainty of the evidence limits confidence in these findings. No consistent age-related differences were observed for tooth sensitivity, while findings for at-home bleaching were inconsistent and evidence regarding gingival irritation and patient-reported outcomes remains limited. Further well-designed clinical studies are needed to clarify the association between patient age and dental bleaching outcomes.