Impact of infected and noninfected human dentine debris on bone healing in rats

Abstract

Aim To evaluate in vivo the bone tissue response of rats to varying amounts of infected and noninfected dentine debris. Methodology Bone tissue reactions were evaluated histologically in 42 Wistar rats after 7, 30 and 60 days. For each animal, three surgical cavities were prepared on the femur and filled with varying amounts (5, 10 or 20 mg) of infected or noninfected dentine debris pellets. In the negative control group, the surgical cavities were not filled. At the end of each experimental period, the animals were euthanized. The samples were processed histologically and analysed using a light microscope. The presence and the severity of inflammatory reaction, as well as hard tissue deposition were evaluated. Data were subjected to statistical analysis and the effects of the dependent variables calculated using nonparametric tests Kruskal–Wallis and Mann–Whitney U with due Bonferroni corrections at P = 0.05. Results At 7 days, the presence of infected debris significantly increased the histopathological scores for neutrophils (P < 0.05), and abscess formation (P < 0.05). Noninfected debris scored significantly higher for lymphocyte infiltrate compared with the control group and infected debris (P < 0.05). Both infected and noninfected debris equally triggered eosinophil cells compared with no‐dentine (P < 0.05). As for giant cells and macrophages, no difference was detected amongst the dentine groups (P > 0.05). Hard tissue deposition was similar regardless of the presence or the bacteriological status of the dentine (P = 1.00). None of the above histopathological parameters was significantly influenced by the amount of debris (P > 0.05). For all parameters evaluated, at 7 days of analysis, the inflammatory response was significantly more intense compared with 30 and 60 days (P < 0.05). Inflammatory parameters were scored similarly for the evaluated groups after 30 and 60 days (P > 0.05). However, hard tissue deposition has significantly increased after 30 days (P < 0.05). No difference was seen between 30 and 60 days of analysis (P = 1.00) for all histological parameters evaluated. Conclusion The assumption that the amount of extruded debris may negatively affect the inflammatory response of bone tissue was not validated in the present in vivo animal study. Infected dentine may trigger acute inflammatory parameters especially during the first 7 days of contact with the tissue; however, in the long term, these negative effects are mitigated.

Debris extrusion during root canal preparation with nickel‐titanium instruments using liquid and gel formulations of sodium hypochlorite in vitro

“…Based on this, it may be questioned if the NaOCl gel used in this study had favoured the packing of debris into the apical third, thus preventing its extrusion. This may be an important clinical dilemma: while debris extrusion will result in an acute inflammatory response (24), hard and/or soft‐tissue debris that is packed into the irregularities of the root canal may interfere with disinfection (25), and the adhesion of root fillings, potentially compromising the treatment outcomes (26,27). Thus, the influence of irrigant formulation on the ability of biocidal agents to reach the most apical and peripheral parts of the root canal system requires further understanding.…”

PRIASE 2021 guidelines for reporting animal studies in Endodontology: explanation and elaboration

“…From Pappen et al . (2019) – ‘Categorical data were analysed statistically using SPSS statistical software (version 24.0, IBM, Chicago, IL, USA). Histopathological events were considered as the dependent variables, whilst debris (infected, noninfected and no‐dentine), amount of debris (0, 5, 10 and 20 mg) and time of evaluation (7, 30 and 60 days) were considered as the independent variables.…”

“…From Pappen et al . (2019) – ‘The minimum number of samples needed to identify differences between groups was determined using the G * Power 3.1 programme for Mac (one‐way ANOVA test from the F family of tests). Due to the absence of previous studies that correlated the volume of extruded dentine with inflammatory tissue reaction, an average effect size of 0.7 was chosen.…”

“…From Pappen et al . (2019) – ‘After the experimental procedures, the animals were placed in cages until their recovery. Two animals were kept per house, with a cycle of 12 h day night − 1, temperature between 19–23 °C, relative air humidity between 40%–70%.…”

“…From Paras et al (2019) -'During the 30 days of the experiment, the health status of the animals (behaviour, changes in the skin and hair, food and water consummation, urinating and defecation) was checked daily'.Example 5i.2FromVerma et al (2017) -'An analgesic (carprofen, 3 mg/kg, subcutaneous, every 24 h) was given immediately prior to the procedure and continued until the following day to manage postoperative pain'.Example 5i.3FromSilva et al (2020) -'During the postoperative period, the rats received analgesia with 5 mg/kg of meloxicam (Eurofarma; São Paulo, SP, Brazil) subcutaneously every 24 h, starting immediately after the surgical procedure and for 2 additional days'.Example 5i.4FromPappen et al (2019) …”