Table 4.
In vitro studies related to the treatment of cracked teeth
| Study | Specimens | Method | Restorations | Outcomes |
|---|---|---|---|---|
| Studies relevant to teeth with normal pulp or reversible pulpitis (n = 3) | ||||
| Kim et al. (2021) | Three‐dimensional cracked tooth models | Finite element analysis | Direct/indirect composite, ceramic inlays/onlays, gold crown with/without resin core | Ceramic inlays/onlays and gold crown with resin core showed the most favorable stress distribution |
| Magne et al. (2012) | Extracted human third molars with standardized MOD+ cavities and simulated cracks | Cyclic fatigue test | Indirect composite inlays/onlays with/without fiber patch | Significantly higher fatigue resistance of onlays compared to inlays; no effect of fiber patch |
| Naka et al. (2018) | Extracted human third molars with standardized MOD+ cavities and simulated cracks | Cyclic fatigue test | Direct/indirect composite with/without cuspal coverage | Significantly higher fatigue resistance of direct groups compared to indirect; no significant effect of cuspal coverage |
| Studies relevant to endodontically treated teeth (n = 3) | ||||
| Anton Y. Otero et al. (2021) | Extracted human third molars with simulated cracks and endodontic treatment | Cyclic fatigue test | CAD/CAM± resin composite endocrowns with/without fiber‐reinforced composite base | A fiber‐reinforced base did not significantly affect the fracture resistance of teeth restored with endocrowns, but it resulted in more fractures being restorable (50‐80%) in comparison to the control group (30%) |
| Lin et al. (2013) | Three‐dimensional finite element premolar models with different crack depths | Finite element analysis | CAD/CAM± ceramic crowns or onlays or endocrowns | Onlays exhibited higher failure probabilities compared to both crowns and endocrowns; endocrowns provided comparable fracture resistance to crowns in cases of shallow cracks (about 1 mm above bone level), but they showed higher failure risk for deep cracks (below bone level to mid‐root) |
| Shi et al. (2021) | Three‐dimensional finite element models with simulated cracks and endodontic treatment | Finite element analysis and fracture failure test | Crowns and onlays with/without different types of fiber reinforcement | Crowns resulted in superior fracture resistance than onlays when both combined with an annular fiber‐reinforced base; fiber‐reinforced onlays exhibited significantly more favorable fracture pattern compared to crowns |