pH changes in radicular dentine associated with calcium hydroxide and corticosteroid/antibiotic pastes.

The aim was to compare hydroxyl ion diffusion through dentine following placement of calcium hydroxide and Ledermix paste. Thirty-six teeth were divided into one control (n = 6) and three experimental (n = 10) groups - (i) Pulpdent paste; (ii) Pulpdent/Ledermix pastes; (iii) Ledermix paste and (iv) Saline. pH was measured in inner and outer dentine cavities over 12 months. Inner dentine time to maximum pH (Tmax ) was 1 week for Pulpdent and 2 weeks for Pulpdent/Ledermix. Pulpdent's outer dentine Tmax was 4 weeks and Pulpdent/Ledermix was 10 weeks. After day 1, Pulpdent pH was higher and this continued for 12 months. Pulpdent's outer dentine pH was higher than Ledermix and controls, but not significantly different from Pulpdent/Ledermix. Pulpdent/Ledermix had significantly higher pH than controls and Ledermix from day 5 until 10 months when Pulpdent/Ledermix outer dentine pH decreased and became similar. In all groups, pH reduced after 3 months.

Efficacy of Different Irrigation Techniques in Removing Ledermix Paste from Simulated Root Canal Irregularities.

Introduction: Root discoloration is reported after using Ledermix paste for prevention of external inflammatory root resorption in traumatically injured teeth. Therefore, it seems necessary to remove Ledermix completely from the root canal prior to root canal filling. The aim of this study was to evaluate the efficacy of sodium hypochlorite or alcohol with or without passive ultrasonic irrigation in removing Ledermix from standardized grooves in coronal and apical root canal thirds. Methods and Materials: Root canals of ten extracted single-rooted teeth were prepared to size 35 and split longitudinally. Standardized grooves were cut in the coronal and apical part of the root canal and filled with Ledermix paste. The reassembled specimens were irrigated with 1% NaOCl or 80% alcohol delivered with a size 30 syringe or with an ultrasonic device. The amount of remaining Ledermix paste was evaluated by three calibrated observers under 30× magnification using a four-grade scoring system. The data was analysed with a nonparametric ANOVA-type method for longitudinal data in factorial experiments. Pairwise comparisons were adjusted by using the Bonferroni corrections (P=0.05). Results: For the coronal groove, no statistical difference between passive ultrasonic irrigation with NaOCl or alcohol was found (P=0.089). Irrigation with ultrasonically activated alcohol was significantly more effective than manual irrigation irrespective of the irrigant (P=0.0118). Ultrasonic activation of alcohol removed Ledermix paste significantly better from the apical groove than the other irrigation procedures (P<0.05). Conclusion: This in vitro study showed that ultrasonic activation of alcohol was the most effective irrigation technique for removal of Ledermix paste, especially in the apical third of the root canal.

Hydroxyl Ion Diffusion through Radicular Dentine When Calcium Hydroxide Is Used under Different Conditions.

Calcium hydroxide's anti-bacterial action relies on high pH. The aim here was to investigate hydroxyl ion diffusion through dentine under different conditions. Teeth were divided into control (n = 4) and four experimental groups (n = 10): Group 1-no medicament; Group 2-Calmix; Group 3-Calmix/Ledermix; Group 4-Calasept Plus/Ledermix; Group 5-Pulpdent/smear layer. Deep (inner dentine) and shallow (outer dentine) cavities were cut into each root. pH was measured in these cavities for 12 weeks. The inner and outer dentine pH in Group 2 was significantly higher than all groups. Inner dentine pH in Group 3 was slightly higher than that in Group 4 initially but subsequently comparable. After Day 2, Group 5 had significantly lower pH than Groups 3 and 4. The outer dentine pH in Group 3 started higher than that in Groups 4 and 5, but by Day 28 the difference was insignificant. The time for the inner dentine to reach maximum pH was one week for Group 2 and four weeks for Groups 3 and 4. The time for the outer dentine to reach maximum pH was eight weeks for all experimental groups. Mixing different Ca(OH)2 formulations with Ledermix gave similar hydroxyl ion release but pH and total diffusion was lower than Ca(OH)2 alone. The smear layer inhibited diffusion.

Prevention and management of external inflammatory resorption following trauma to teeth.

External inflammatory resorption is one of the potential consequences of trauma to the teeth. It occurs when there has been loss of cementum due to damage to the external surface of the tooth root during trauma, plus the root canal system has become infected with bacteria. It is characterized by the radiographic appearance of loss of tooth substance with a radiolucency in the adjacent periodontal ligament and bone. The loss of cementum allows the intracanal bacteria and/or their endotoxins to reach the periodontal ligament more readily and this can lead to the development of the inflammatory resorptive process. External inflammatory resorption can ultimately lead to loss of the tooth if it is not managed in a timely manner. There are some injuries that are very likely to develop this type of resorption and a preventive approach can be adopted by commencing root canal treatment immediately as part of the emergency management of such cases. In cases where the resorptive process is already established, root canal treatment can arrest the resorption and encourage hard tissue repair. The use of a corticosteroid-antibiotic intracanal medicament has been shown to be particularly useful in the prevention and management of external inflammatory resorption. Calcium hydroxide should not be used as an immediate medicament because of its inherent toxicity and irritant properties but it is valuable as a subsequent medicament to encourage hard tissue repair where required. This review outlines the external inflammatory resorptive process and the management strategies that can be employed to prevent it from occurring, and to treat it if already present.

Allergic reaction to the tetracycline component of Ledermix paste: a case report.

AIM: Allergy to materials used during root canal treatment is well recognized in the endodontic literature. However, allergy to Ledermix paste, a compound containing triamcinolone (a corticosteroid) and demeclocycline (a tetracycline antibiotic), has not been reported apart from one very recent case in a Letter to the Editor of a journal. The aim of this report is to describe a proven allergic reaction to tetracycline following the use of Ledermix paste as a root canal medicament. SUMMARY: A 33-year-old female patient undergoing root canal retreatment of her right mandibular second premolar tooth experienced symptoms of type 1 allergy following the placement of an intracanal medicament containing a mixture of Ledermix paste and calcium hydroxide [Ca(OH)2 ]. Signs of the type 1 allergy included urticaria, pruritus all over the body, general malaise and fever. These all subsided after removing and flushing out the Ledermix paste-Ca(OH)2 mixture and redressing the root canal with Ca(OH)2 alone. Allergic scratch tests were performed, and these confirmed that the patient was allergic to tetracycline, one of the components of Ledermix paste.