Impact of apical extent of root canal filling on vertical root fracture: a case–control study

Abstract

Aim To investigate the impact of apical extent of root filling on vertical root fracture (VRF) in a case–control study. Methodology Eighty‐six patients (119 roots) diagnosed with VRF in crowned root filled anterior and posterior teeth were selected. The cases were matched individually with control teeth in a ratio of 1:1 for age (±5 years), gender, tooth type, canal instrumentation method, master apical file (MAF) size and taper, technique of canal filling and time period after root filling. All root canals had been prepared using nickel–titanium (NiTi) rotary instruments and filled using the lateral compaction technique. The apical extent of root filling (overfilled to or beyond the radiographic apex or not overfilled and short of the radiographic apex) was recorded as the dependent variable by two individual examiners. Inter‐examiner agreement was obtained using Kappa statistics. Recorded numbers of overfilled and not overfilled canals in cases and controls were analysed using chi‐square tests and conditional logistic regression, and odds ratio was calculated. In addition, the frequency distribution of vertical and cross‐sectional extensions and the course of VRFs were evaluated. Results The mean age of patients with VRFs was 50 ± 10 years with 27 (31%) males and 59 (69%) females. The Kappa score for inter‐observer agreement was 0.832 (P < 0.001). There was a significant difference between cases and controls with respect to apical extent of root filling (P < 0.0001). When compared to roots not overfilled, overfilled roots had 11.5 times higher odds for occurrence of VRF (OR = 11.5; CI: 4.99 – 26.48). Most VRFs had a complete corono‐apical longitudinal extension and were present bucco‐lingually/palatally. Conclusion After matching for age, gender, tooth type, MAF size and taper, canal filling technique and time period after root filling, root canals filled to or beyond the radiographic apex following lateral compaction had a greater association with VRF than canals filled short of the radiographic apex.

PROBE 2023 guidelines for reporting observational studies in endodontics: Explanation and elaboration

“…From PradeepKumar et al (2019)—‘Cases were individually matched with controls in a ratio of 1:1 for age (±5 years), gender, tooth type, instrumentation system, master apical file (MAF) size and taper, technique of canal filling and time period from canal filling (similar or more for controls). Cases and controls were selected from a pool of patients treated by three qualified endodontists with more than 10 years of experience.…”

Cracked Teeth: A Review of the Literature

“…15,37,38 Pitts et al, (1983) reported that a spreader load of 7.2 kg resulted in a vertical root fracture of a maxillary incisor, with 16% of the teeth tested fracturing at loads less than 10 kg. 39 However, the mean load required to induce fracture ranges from 10-20 kg. 37,38,39 A study compared the effects of lateral compaction with the continuous wave technique.…”

“…39 However, the mean load required to induce fracture ranges from 10-20 kg. 37,38,39 A study compared the effects of lateral compaction with the continuous wave technique. Their results showed that root canal preparation and obturation had significantly more defects as compared to unprepared teeth.…”

“…A recent study that investigated the impact of apical extent of root filling, concluded vertical root fractures had a greater association with root canals filled to or beyond the radiographic apex as compared to root canals filled short of it ,when the age, gender, tooth type, MAF size and taper, canal filling technique and time period after root filling were controlled. 39…”

Vertical root fractures: A time-dependent clinical condition. A case-control study in two colombian populations

“…The loss of the protective effect of the pulp tissue during chewing adds to the microstructural changes in the dentin that promote instrumentation; the chemical conditioning ( 8 ) and excessive forces during filling ( 9 ) are plausible factors that contribute to the failure of the dental structure, especially over time. Therefore, if 66% of VRFs were diagnosed between 2 to 5 years from the completion of root canal treatment ( 9 ), the structural changes that the treated root dentin undergoes are considered time-dependent, and the multifactorial nature of the vertical fracture does not allow the identification of a single risk factor ( 4 ). Thus, tooth structural loss, viscoelasticity loss, age-induced changes in the dentin, and restorative procedures are primary factors that usually predispose the teeth to immediate fracture.…”