The ability of platelet-rich plasma to regenerate a non-vital immature permanent teeth / Capacidade do plasma rico em plaquetas de regenerar dentes permanentes imaturos não vitais

Objective: To test the ability of platelet-rich plasma clinically and radiologically for pulp regeneration of immature teeth with apical periodontitis. Material and Methods: An experimental study was conducted From (March/2018-July/2020) 12 upper central immature incisors with acute apical periodontitis and necrotic pulp from six patients receiving regenerative endodontic treatment using concentrated platelets rich plasma were performed by the same endodontist at Mediclinic Middle East Hospitals. Informed consent, including explanation of risks and alternative treatments or no treatment were prepared and filled by the patient parents. The therapeutic protocol was involved accessing the pulp chamber; irrigation copiously with sodium hypochlorite; applying calcium hydroxide as intracanal medicament and a provisionally sealing it after 4 weeks. The canal was cleaned, dried and injected with concentrated platelets rich plasma which serve as a scaffold for pulp regeneration. MTA was used to seal the chamber before final filling with composite. Evaluations: All teeth were monitored clinically (mobility, palpation, percussion, and sensitivity cold test) and radiographically. Results: Twenty months follow-up all teeth showed resolution of periapical radiolucencies, continued root development with positive response to sensitivity cold test and no discoloration. Conclusion: The results of this study confirmed the previous finding that pulp regeneration can be gained by using cPRP successfully. (AU)

Objetivo: Testar a capacidade do plasma rico em plaquetas clinicamente e radiograficamente para a regeneração pulpar em dentes imaturos com periodontite apical. Material e Métodos: O estudo experimental foi realizado em Março/2018 e Julho/2020, 12 incisivos centrais imaturos com periodontite apical aguda e necrose pulpar em 6 pacientes recebendo tratamento endodôntico regenerativo usando concentrado de plasma ricas em plaquetas. Foram realizadas pelo mesmo endodontista no Hospital Mediclinic Middle East. O consentimento informado incluindo explicação do risco e tratamentos alternativos ou de nenhum tratamento foi preenchido pelos responsáveis do paciente. O protocolo terapêutico envolveu acesso à câmara pulpar, irrigação abundante com hipoclorito de sódio, aplicação de hidróxido de cálcio como medicação intracanal e selado intracanal por 4 semanas. O canal foi limpo, seco e injetado concentrado de plasma rico em plaquetas que servem como um scaffold para a regeneração pulpar. Usou-se MTA para selar a câmara antes do preenchimento final com compósitos. Avaliações: Todos os dentes foram monitorados clinicamente (mobilidade, palpação, percussão e teste de sensibilidade com frio) e radiograficamente. Resultados: Após 20 meses de acompanhamento, todos os dentes apresentaram a resolução das radioluscências periapicais, desenvolvimento contínuo da raiz com resposta positiva ao teste de sensibilidade ao frio e sem descoloração. Conclusão: O resultado do estudo confirmou descobertas anteriores que a regeneração pulpar pode ser obtida usando cPRP com sucesso. (AU)

Evaluation of root and canal morphology of maxillary permanent first molars in an Emirati population; a cone-beam computed tomography study.

BACKGROUND: The aim of this study was to analyze the root and canal morphology of the maxillary permanent first molars in an Emirati population using cone-beam computed tomography (CBCT). METHODS: Two hundred and sixty-one CBCT scans were acquired. The data were extracted and anonymized to remove all patient identifiers. Two observers (an endodontic resident and an endodontist) evaluated all scans on diagnostic quality monitors. RESULTS: The prevalence of a second mesiobuccal canal (MB2) was 80.1% in all examined samples. Type II Vertucci classification, was the most common canal configuration (59%) in the mesiobuccal root, followed by Types I (19.9%) and IV (15.3%), while Type III was the least common (5.7%). Types I, II, and IV were significantly more common in the 21-40-year age group (P < 0.001), while Type III was observed significantly more often in the < 20-year age group (P < 0.001). No significant effect of gender on the prevalence of Vertucci classification in the mesiobuccal root of maxillary first molars (P = 0.74) was found. Analysis of bilateral symmetry showed that 80% teeth had perfect bilateral symmetry, whereas 20% were asymmetrical. Type II canal configuration showed the highest prevalence of bilateral symmetry (48.7%), followed by Type I (15%) and Type IV (10%), while Type III showed the least prevalence of symmetry (3%). CONCLUSIONS: This was the first study to analyze the prevalence of MB2 canal in an Emirati population. Our results indicate high prevalence of MB2 (80.1%) and emphasize the importance of using advanced techniques to locate the MB2 canal.

Fracture resistance of overtly flaring root canals filled with resin-based obturation material.

BACKGROUND: Reinforcement of root canals obturated with Resilon was reported by several investigators, but no studies reported the reinforcement of overtly flared root canals obturated with Resilon material. The aim of this study was to investigate the fracture resistance of overtly flared root canals filled with Resilon as compared to similar root canals filled with gutta-percha (GP). MATERIALS AND METHODS: Sixty single-rooted premolars were divided randomly into six groups. Group 1 served as control group. The control group was sub-divided into two groups, a negative group and a positive group. The negative group consisted of root canals that were only cleaned from residual pulpal tissues, however, the positive group had prepared and overtly flared root canals without obturation. Groups 2 and 4 were shaped using 0.04 taper rotary files, while groups 3 and 5 were shaped using 0.06 taper rotary files. Before obturation, the last four groups were further flared coronally with a reverse cone diamond bur. Groups 2 and 3 were obturated with GP and a resin-based sealer, while groups 4 and 5 were obturated with Resilon and Epiphany self-etching primer and Epiphany sealer. Roots were then fixed into a universal testing machine and vertically loaded until fracture. SPSS software (Release 9.0 for Windows, SPSS, Chicago, USA) was used to perform the statistical analysis. RESULTS: Fracture resistance measurements showed that there were differences in resistance to fracture among the experimental groups (ANOVA, P < 0.0001). Mean values of the loading force applied to the negative control group were the highest at 1.81 KN, whereas the mean values for the Resilon groups (Groups 4 and 5) at 1.13 KN and 1.54 KN were found to be higher than the GP groups (Groups 2 and 3) at 0.45 KN and 0.88 KN, respectively. Tukey's post hoc test showed that there was no statistical difference between the mean values of the negative control group and Group 5 (P = 0.69). CONCLUSION: Obturation of overtly flared roots with Resilon material increased the resistance of these teeth to vertical root fracture.

Fracture resistance of over-flared root canals filled with MTA and resin-based material: an in vitro study

Aim: To measure the fracture resistance of over-flared roots filled with a variety of materials (gutta-percha-nano HA, resilon-epiphany, composite and mineral trioxide aggregate - MTA) using the Instron machine test and micro-computed tomography (Micro CT) Scan. In addition, scanning electron microscopy (SEM) images were used to illustrate the type of fracture patternsof the specimens. Methods: One hundred and twenty extracted human mandibular single rooted premolars were selected. A total of 105 out of the selected teeth were prepared to the working length and over-flared, leaving the apical 5 mm undisturbed. Fifteen samples had no treatment and were used as a positive control group (Group +ve). The 105 test teeth were further divided into 7 groups of 15 samples each. One of the 7 groups was designated as negative control (Group -ve) where teeth were over prepared and left without obturation.Remaining groups were filled with gutta-percha-nanoHA (Group1), gutta-percha-nano HA+composite (Group 2), gutta-percha-nano HA+MTA (Group 3), resilon-epiphany (Group 4),resilon-epiphany+composite (Group 5), and resilon-epiphany+MTA (Group 6). Fracture resistance of all samples was measured using the Instron testing machine. Three samples from each group had the depth of their fracture line measured by Micro CT Scan, and 2 samples from each group had their fracture pattern illustrated using SEM. Results: The highest fracture resistance was observed in Group +ve, followed by Groups 3, 6, 5, 2, 4, 1, and Group -ve, with values (in N) of: 1598 (641.0), 1190.5(424.2), 1164.7 (489.4), 821.2 (220.9), 683.4(179),658.4 (211.3), 658.4 (99.0), 158.3(49.3), respectively. Statistical analysis for root fracture resistance showed highly significant difference between all groups with p value < 001.Conclusions: Micro CT Scan and SEM analysis indicated the ability of MTA to withstand vertical force.

Sealing ability of gutta-percha/Nano HA versus Resilon/Epiphany after 20 months using an electrochemical model: an in vitro study

Aim: To evaluate the sealing ability of gutta-percha-nano-HA and Resilon-Epiphany by electrochemical method and micro-computed tomography (CT) scan at 48 h and 20 months using three different obturation techniques (cold lateral condensation technique, warm vertical condensation - System B, and warm vertical condensation with vibration - Down-Pak). Methods: 150 human mandibular single-rooted premolars were prepared and randomly allocated into 6 groups of 25 specimens each, and filled with either gutta-percha-nano HA or Resilon-Epiphany with the three different obturation techniques (cold lateral, warm vertical - System B, and warm vertical with vibration - Down-Pak). Electrochemical microleakage method was used to measure the microleakage after 48 h and after 20 months, and a micro-CT Scanner 1072 was used to evaluate the quality of obturation after 48 h. Results: Group 6 (Resilon-epiphany/Down-Pak technique) had the highest microleakage value, followed by Group 2 (Gutta-percha-nano HA/ System B technique), Group 4 (Resilon-Epiphany/Lateral condensation technique), Group 3 (Gutta-percha-nano HA/Down-Pak technique), Group 5 (Resilon-Epiphany/System B technique), and Group 1 (Gutta-percha-nano HA/Lateral condensation technique) with the values of 4.69 (6.06) KÙ, 3.88 (2.92) KÙ, 3.77 (3.75) KÙ, 3.38 (3.92) KÙ, 2.64 (2.90) KÙ, and 2.44 (4.34) KÙ, respectively. No significant difference in the quantity of leakage was observed for each root in each group between the two tested filling materials and their sealers (p=0.143). Micro CT scan investigations revealed more micro-voids in the Resilon-Epiphany Group obturated with Down- Pak technique. Conclusions: Nano-hydroxyapatite sealer with gutta-percha filling material provided a reasonable seal compared with Epiphany sealer and Resilon filling material.