Colour change and fracture resistance of endodontically treated teeth after staining and walking bleach: role of filling strategy
Odontology, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10266-026-01501-5
- Dergi Adı: Odontology
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE, Natural Science Collection (ProQuest), Biological Science Database (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest), Pharma Collection (ProQuest)
- Anahtar Kelimeler: AH Plus, Bioceramic sealer, Colour change, Fracture resistance, Intracoronal bleaching
- Hacettepe Üniversitesi Adresli: Evet
Özet
The present study aimed to evaluate the effect of different root canal sealers and obturation strategies on colour stability and fracture resistance of maxillary incisors following a staining and walking bleaching protocol. One hundred and twenty human maxillary incisors were prepared and allocated to six groups (n = 15) according to sealer type (AH Plus or MTA Cem S), presence of gutta-percha, and application of staining/bleaching procedures. Two additional groups included teeth that underwent staining/ bleaching without endodontic treatment and intact teeth. Colour was measured spectrophotometrically in the CIE Lab* colour space at serial time points, and CIEDE2000 (ΔE00) values were calculated for interval-specific and cumulative colour change. Fracture resistance was measured in Newtons using a universal testing machine, and fracture patterns were classified as repairable or non-repairable. Colour-coordinate data were analysed using linear mixed-effects models. ΔE00 values and fracture resistance were compared using one-way ANOVA followed by Tukey HSD test. In the six experimental root-filled groups, a 2 × 3 factorial ANOVA was additionally performed to examine the interaction between bleaching status and filling strategy. Repairability was analysed using the Pearson chi-square test. Significant within-group changes in L* and a* values were observed across all experimental conditions, whereas significant changes in b* values were detected in the staining/bleaching groups-including those with gutta-percha combined with AH Plus, gutta-percha combined with MTA Cem S, MTA Cem S alone, and the staining/bleaching control—as well as in the intact control group, but not in the corresponding non-stained/non-bleached groups. Significant between-group differences were found for ΔE00 2-1, ΔE00 4-2, and ΔE00 4-1, whereas ΔE00 3-2, ΔE00 4-3, and ΔE00 3-1 did not differ significantly among groups. The greatest residual overall colour change was observed in gutta-percha combined with AH Plus. Gutta-percha combined with MTA Cem S yielded the highest mean fracture resistance (p < 0.05). In the factorial analysis of experimental groups, fracture resistance and ΔE00 4-1 both showed significant bleaching × filling-strategy interactions. Repairability did not differ significantly among groups. Gutta-percha combined with MTA Cem S yielded the highest mean fracture resistance, whereas the AH Plus–containing stained/bleached condition showed the greatest residual colour change. The aesthetic and mechanical outcomes observed after the staining/bleach sequence should be interpreted in conjunction with the overall filling-restorative condition rather than as isolated effects of bleaching alone.