Discoloration of teeth undergoing REPs is an unfavorable outcome. Considering the significant contribution of TAP containing minocycline to the coronal tooth discoloration even after sealing the pulp chamber walls, the revision of current guidelines in relation to the use of TAP with minocycline might need to be revised.

ObjectivesThis study aimed to compare the surface microhardness of mineral trioxide aggregate (MTA) samples having different thicknesses and exposed to human blood from one side and with or without a moist cotton pellet on the other side.Materials and MethodsNinety cylindrical molds with three heights of 2, 4, and 6 mm were fabricated. In group 1 (dry condition), molds with heights of 2, 4, and 6 mm (10 molds of each) were filled with ProRoot MTA (Dentsply Tulsa Dental), and the upper surface of the material was not exposed to any additional moisture. In groups 2 and 3, a distilled water- or phosphate-buffered saline (PBS)-moistened cotton pellet was placed on the upper side of MTA, respectively. The lower side of the molds in all the groups was in contact with human blood-wetted foams. After 4 day, the Vickers microhardness of the upper surface of MTA was measured.ResultsIn the dry condition, the 4 and 6 mm-thick MTA samples showed significantly lower microhardness than the 2 mm-thick samples (p = 0.003 and p = 0.001, respectively). However, when a distilled water- or PBS-moistened cotton pellet was placed over the MTA, no significant difference was found between the surface microhardness of samples having the abovementioned three thicknesses of the material (p = 0.210 and p = 0.112, respectively).ConclusionsIt could be concluded that a moist cotton pellet must be placed over the 4 to 6 mm-thick MTA for better hydration of the material. However, this might not be necessary when 2 mm-thick MTA is used.

Objectives This study aimed to evaluate the cytotoxicity of minimum antibacterial values of medicaments used in endodontic regeneration on stem cells. Materials and Methods “Minimum inhibitory concentration,” “minimum bactericidal concentration,” and “minimum biofilm inhibitory concentration” of triple and double antibiotic paste, a modified triple antibiotic paste (minocycline replaced by clindamycin), Augmentin, and calcium hydroxide were determined using Enterococcus faecalis (ATCC 29212) by microtiter plate method. Direct cytotoxic effects of drugs were evaluated by lactate dehydrogenase and water-soluble tetrazolium salt-1 assays using stem cells of apical papilla obtained from immature third molars via enzymatic digestion. Statistical Analysis Data were analyzed using IBM SPSS Statistics 24, one-way analysis of variance and post hoc comparisons. The statistical power was set at p < 0.05. Results All medicaments caused similar cytotoxicity and cell proliferation at “minimum inhibitory concentration” (p > 0.05) except Augmentin which was significantly more toxic than others (p < 0.05). At “minimum bactericidal concentration,” calcium hydroxide was more toxic than other drugs (p < 0.001), but its adverse effect on cell proliferation was the same as Augmentin (p > 0.05). Triple and double antibiotic paste revealed similar favorable effects in terms of toxicity and proliferation rate at most of the tested concentrations (p > 0.05). At “minimum biofilm inhibitory concentration” both the modified paste and Augmentin caused less proliferation rate than triple and double antibiotic paste (p < 0.001and p < 0.05, respectively) and Augmentin induced more cytotoxicity (p < 0.05). Conclusions Considering the antimicrobial potency, triple antibiotic paste seems to be the safest drug for the stem cells of apical papilla, while Augmentin may have some adverse effects.

The treatment objective for children with avulsed anterior teeth should concentrate on preserving the alveolar bone volume and contour. Posttraumatic external inflammatory root resorption (EIRR) is also a high-risk complication often observed in children. Regenerative endodontic procedure (REP) has been considered a successful treatment to arrest EIRR, especially in posttraumatic cases. This case report presents clinical outcomes of REP in two teeth of an 8-year-old systemically healthy patient with a history of severe dentoalveolar traumatic injury, one with a history of avulsion, and the other with an EIRR. The treatment consisted of REP on both teeth #8 and #9. The results showed some evidence of maturation in the apical third of tooth #9 and resolution of signs and symptoms on tooth #8.

Introduction:This study aimed to examine the effects of induced inflammatory tooth pain on anxiety level in adult male rats.Methods:The mandibular incisors of 56 adult male rats were cut off and prefabricated crowns were fixed on the teeth. Formalin and capsaicin were injected intradentally to induce inflammatory tooth pain. Diazepam treated group received diazepam 30 minutes before intradental injection. The anxiety-related behavior was evaluated with elevated plus maze test.Results:Intradental application of chemical noxious stimuli, capsaicin and formalin, significantly affected nociceptive behaviors (P<0.001). Capsaicin (P<0.001) and formalin (P<0.01) significantly increased the anxiety levels in rats by decrease in the duration of time spent in open arm and increase in the duration of time spent in closed arm. Rats that received capsaicin made fewer open arm entries compared to the control animals (P<0.05). Capsaicin (P<0.001) and formalin (P<0.01) treated rats showed more stretch attend postures compared to the control and sham operated animals. In diazepampretreated rats, capsaicin induced algesic effect was prevented (P<0.001).Conclusion:Inflammatory pulpal pain has anxiogenic effect on rats, whereas diazepam premedication showed both anxiolytic and pain reducing effects.

Regenerative endodontic treatment (RET) is a valuable treatment for necrotic immature teeth with many advantages such as increasing root length and thickness of root wall. The success of RETs is based on healthy stem cells, suitable scaffolds, and growth factors and takes place when bacterial contamination is well controlled. The aim of this article is to address controversy in a case with multiple success criteria. This paper reports a 9-year-old boy with a complicated crown fracture of the maxillary left central incisor about three years prior to referral with a diagnosis of intrusive luxation with spontaneous reeruption. The tooth had an underdeveloped root and a well-defined periapical radiolucent lesion around the root apex. RET was considered according to the stage of root development. Upon the three-week recall session, the clinical examination indicated that the patient was asymptomatic in the affected site. However, the patient returned two weeks later with a sinus tract pertaining to the apex of tooth #9. Therefore, debridement of the root canal space was repeated and the RET redone. On the second trial, the patient was symptom-free, but no more evidence of root maturation was observed on 18-month follow-up. The tooth was asymptomatic (without swelling, drainage, and pain) during this time, and esthetics was provided for the patient.

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Background: PRF as one of the favorable scaffolds in Regenerative Endodontic Treatment (RET), has several limitations such as the need for blood sampling and special equipment. High available commercial scaffolds such as fibrin are able to meet all the necessary requirements of dentin tissue engineering. The present study was designed to evaluate the effect of PRF and fibrin gel, with and without the presence of EDTA-treated radicular dentin segments on SCAP viability, proliferation, migration, and differentiation.Methods: Radicular dentin were prepared from extracted teeth and treated by EDTA 17% .The samples were divided into 6 groups: Dentin/PRF/Cell, Dentin/Fibrin/Cell, Dentin/Cell, PRF/Cell, Fibrin/Cell and Cell (Control). SCAP viability was assessed using MTT assay. Gene expression levels of odontogenic markers [Dentin sialophosphoprotein (DSPP), Dentin matrix protein 1(DMP1), Collagen type I Alpha 1(COL 1A1) and Alkaline phosphatase (ALP) were assessed using qrt-PCR. Cell migration were also evaluated by means of scratch test. Results: The results of MTT assay at showed that the viability of SCAP significantly increased after 7 days for both groups containing fibrin (P <0.05). The viability of SCAP seeded on Dentin/PRF and PRF significantly decreased after 7 days (P <0.001). The odontogenic markers were significantly expressed for both scaffolds in the presence of dentin segment (p<0.05). Significant decrease in scratch area was seen in Fibrin/Dentin group (p < 0.001)Conclusions:Fibrin beside EDTA-treated dentin showed great ability in survival, proliferation, differentiation, and migration of SCAP rather than PRF.