Effect of intracanal medications on the interfacial properties of reparative cements

Efficacy of alendronic acid solution in removal calcium hydroxide from root canals

Background

Intracanal medication is considered an alternative after instrumentation in the case of pulp necrosis. However, the elimination of this medication plays an important role in the obturation process, which is why various chelating solutions have currently been studied for this purpose. Therefore, this study aimed to analyze the irrigant based on alendronic acid (AA), which contains in its chemical structure functional groups capable of forming complexes with Ca2+ ions.

Material and Methods

90 single-rooted teeth were crowned and standardized to a length of 13 mm. They were instrumented with a progressive K file (Dentsply Maillefer) from #15 to #30. Ca(OH)2 was placed as intracanal medication for 7 days. The roots were randomly divided into the following 4 experimental groups (n=13) according to the irrigant used: 2.25% NaClO, calcium suspension, 0.22% AA, and 10% citric acid; as well as negative (n=5; saline solution) and positive controls (n=5, 17% EDTA). The roots were divided longitudinally and the % of permeable dentinal tubules (% PDT) was determined by thirds (cervical, middle and apical), by analyzing the micrographs obtained by scanning electron microscope (SEM) and the imageJ program. The quantification of the remaining Ca2+ was determined using the Arsenazo III technique.

Results

The Kruskal Wallis test was used for the % of permeable dentinal tubules where a significant difference was determined for the different thirds (p<0.005). In the apical third, citric acid and AA irrigants presented a median of 17.71 and 17.51 % PDT respectively. In relation to the quantification of the remaining total calcium, the lowest value was found with AA with a concentration of 4.83 mmol/L.

Conclusions

The 0.22% AA solution has the same capacity to remove Ca(OH)2 from the root canal walls as 17% EDTA and 10% citric acid. Key words:Alendronic acid, calcium hydroxide, citric acid, EDTA, irrigant solution,root canal.

Effects of calcium hydroxide intracanal medicament on push-out bond strength of endodontic sealers: A systematic review and meta-analysis

OBJECTIVE

To investigate the effect of calcium hydroxide intracanal medicament on the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.

METHODS

A comprehensive search of was conducted for all relevant in-vitro studies. All randomized controlled in-vitro studies that evaluated the effect of calcium hydroxide on the push-out bond strength of resin-based or calcium silicate-based endodontic sealers were assessed. The variables of interest were extracted, and the risk of the included studies was evaluated. The standardized mean difference was calculated and the significance level was set at p value <0.05.

RESULTS

A total of 26 studies were eligible for analysis. There were 45 independent comparison groups and 1009 recruited teeth. The pooled data showed no significant difference in push-out bond strength between calcium hydroxide and control group in the resin-based group (SMD = 0.03; 95% CI = -0.55, 0.60; p = 0.93), and calcium silicate-based group (SMD = 0.02; 95% CI = -0.31, 0.35; p = 0.90). Most of the studies (21 out of 26) were at medium risk of bias and five studies showed a low risk of bias.

CONCLUSION

The available evidence suggests that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of the resin- and calcium silicate-based endodontic sealers.

CLINICAL SIGNIFICANCE

The results of this meta-analysis suggest that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.

Evaluation of a Novel Tool for Apical Plug Formation during Apexification of Immature Teeth

The purpose of this study was to compare the sealing ability and time required for the formation of Biodentine and mineral trioxide aggregation (MTA) apical plugs, using three different delivery methods: an amalgam carrier (AC), the Micro Apical Placement (MAP) System or a novel tool using a modified cannula (MC). Materials and Methods: A total of 60 uniformed molar roots were divided into three main groups, according to the technique of apical plug formation: AC, MAP, and MC. Each group was divided into two subgroups, according to the filling material used: MTA and Biodentine. A timer was used to calculate the required time for apical plug formation. After setting the filling materials, the apical microleakage of the formed plugs was quantified using the dye extraction method and spectrophotometry. The differences between the groups were analyzed using the one-way ANOVA and LSD post hoc tests. The significance level was set at 0.05. Results: No significant differences were reported in the time required to form the apical plugs in all groups (p > 0.05). However, the apical plugs formed by the AC method had significantly higher microleakage than those formed using the MAP and MC methods (p < 0.05). Conclusion: Within the limitations of this study, the sealing ability of the apical plugs formed by the MC method is comparable to the MAP method and better than the AC method.

Do intracanal medications used in regenerative endodontics affect the bond strength of powder-to-liquid and ready-to-use cervical sealing materials?

Aim:

This study evaluated the effect of four intracanal medications commonly used in regenerative endodontic procedures on the bond strength of four calcium silicate-based materials, in which two are powder-to-liquid products (MTA and MTA-HP) and the other are ready-to-use materials (EndoSequence Root Repair Material Fast Set Putty [ERRM] and Bioceramic Repair [BIO-C Repair]).

Methods:

Ten bovine central incisors were selected and 4 slices (1.0 ± 0.1 mm) were prepared from each root. Next, four 0.8-mm wide holes were drilled in each slice and specimens were filled with one of the following intracanal medications: triple antibiotic paste, double antibiotic paste, calcium hydroxide with distilled water, and calcium hydroxide with 2% chlorhexidine gel. After 21 days, holes were filled with one of the materials: MTA, MTA-HP, ERRM, or BIO-C Repair. After storage, push-out test and failure analysis were performed. Data were submitted to analysis of variance in a 4 × 4 factorial scheme. Tukey's test was used for multiple comparisons.

Results:

The use of different interappointment dressings did not influence the results (P > 0.05). ERRM and BIO-C Repair presented significantly higher values than MTA and MTA-HP (P < 0.0001). Specimens showed a 100% occurrence of adhesive failures.

Conclusion:

The use of different intracanal medications presented similar impact on bond strength of calcium silicate-based materials. Ready-to-use ERRM and BIO-C Repair materials presented the best push-out values to dentine, whereas powder-to-liquid MTA and MTA-HP cements showed the lowest results.