Effect of Foraminal Enlargement on Periapical Healing in Necrotic Teeth: A Systematic Review.

Introduction: Foraminal Enlargement (FE) is a cleaning performed in the apical-most region of the tooth, in order to optimize root disinfection. This systematic review evaluated the influence of FE during root canal treatment on bacterial reduction and repair of the periapical lesion. Materials and Methods: Searches in PubMed/MEDLINE, Scopus, Cochrane Library, Web of Science, Embase, Scielo, Lilacs and OpenGrey were performed until January-2024. Ex vivo and in vivo studies evaluating the effects of FE in the bacterial reduction and repair of the periapical lesion were included, respectively, followed by risk of bias assessment (modified version of Joanna Briggs Institute's for ex vivo studies and Systematic Review Centre for Laboratory animal Experimentation's risk of bias tools for in vivo studies). The meta-analysis was not feasible and a qualitative summary for each outcome was provided. Results: Of 950 studies, 2 in vivo studies were eligible, using animal models with infected teeth. Of these two, periapical repair was evaluated with hematoxylin-eosin stain, and FE improved periapical healing. Regarding ex vivo studies, 3 were eligible, using extracted human teeth. The inoculations in ex vivo models were performed with Enterococcus (E.) faecalis, and FE reduced E. faecalis in the ex vivo models. Conclusions: Foraminal enlargement seems to increase bacterial reduction within the root canal, and provide major periapical tissue repair on the histological analysis in animal studies. However, caution is necessary when translating these results to the clinical environment.

Alargamento do forame como complemento no tratamento endodôntico para regeneração de uma lesão periapical extensa: relato de caso / Foraminal enlargement as a complement in the endodontic treatment for the regeneration of an extensive periapical lesion. A case report

Introdução: O alargamento do forame refere-se ao alargamento mecânico intencional do forame para reduzir a carga bacteriana em uma área afetada frequentemente por infecções endodônticas além do limite da constrição apical. Objetivo: O objetivo do presente relato de caso é apresentar a técnica de alargamento do forame de um dente com lesão periapical extensa, como complemento do tratamento endodôntico e alternativa precoce à microcirurgia periapical. Métodos: É apresentado o caso de um incisivo lateral superior endodonticamente tratado, com uma extensa lesão periapical associada. Devido à história clínica e radiográfica, tempo decorrido desde o tratamento endodôntico inicial e alta probabilidade de áreas de reabsorção apical com biofilme extrarradicular, o retratamento endodôntico com alargamento do forame foi indicado como primeira opção, adiando a indicação de cirurgia endodôntica de acordo com a evolução. Resultados: Na avaliação de acompanhamento de dois anos, por exame de imagem, observou-se evolução clínica favorável ao retratamento, com aumento total da densidade óssea. O procedimento cirúrgico endodôntico complementar foi descartado. Conclusão: O alargamento do forame é uma alternativa complementar viável em casos de periodontite apical de longa duração com suspeita de biofilme no nível do forame. Pode ser considerado uma opção antes da indicação de retratamento endodôntico cirúrgico (AU).

Introduction: Foraminal enlargement refers to intentional mechanical enlargement of the foramen to reduce the bacterial load in an area frequently affected by endodontic infections beyond the limits of the apical constriction. The objective of this case report is to present the foraminal enlargement technique of a tooth with an extensive periapical lesion as a complement in the endodontic treatment and an early alternative to periapical microsurgery. Materials and methods: The case is presented of an endodontically treated upper lateral incisor with an extensive associated periapical lesion. Due to the clinical and radiographic history, the time elapsed since the initial endodontic treatment, and the high probability of areas of apical resorption with extra-radicular biofilm, endodontic retreatment with foraminal enlargement was indicated as the first option, postponing the indication for endodontic surgery according to evolution. Results: In the follow-up appointment at 2 years, a favorable clinical imaging evolution of retreatment was observed, with a total increase in bone density. The complementary endodontic surgical procedure was discarded. Conclusion: Foraminal enlargement is a viable complementary alternative in cases of long-term apical periodontitis with suspicion of biofilm at the foramen level. It can be considered an option before the indication of surgical endodontic retreatment (AU).

Influence of apical enlargement on the repair of apical periodontitis in rats.

AIM: To evaluate the influence of different apical enlargement protocols on the radiographic and histological healing of apical periodontitis in rats. METHODOLOGY: Apical periodontitis was induced bilaterally in the mandibular right and left first molars of 24 Wistar rats by pulp exposure to the oral cavity for 3 weeks. A standard serial root canal preparation technique was performed in the molar of one side, whilst the opposite side was the control group. Rats were randomly divided into three experimental groups (n = 8), according to the diameter of apical enlargement during root canal preparation: K-files size 20 (EG1), size 25 (EG2) and size 30 (EG3). Each animal was its own positive control, because the opposite arch remained untreated. Root canals were filled with a standard technique. After 3 weeks, the animals were euthanized. The main outcome of apical periodontitis healing was evaluated radiographically (mm2 ) and histologically (ordinal scores of inflammation) using a HE staining technique. The measurement of effect was obtained between the three experimental groups by carrying out generalized estimating equations, with Poisson regression with robust variance, pairing each experimental group with its respective control group within animals, adjusted for the mean within animal differences, with α = 5%. RESULTS: The mean and standard deviations of radiographic apical periodontitis size (mm2 ) and intensity of histological inflammatory scores were, respectively: EG1 (0.44 ± 0.27; 2.25 ± 0.46), EG2 (0.33 ± 0.10; 2.50 ± 0.53) and EG3 (0.22 ± 0.08; 2.63 ± 0.74). After 3 weeks, a significantly more favourable radiographic repair was observed when larger apical enlargement was performed (EG3), compared to EG1 and EG2 (P = 0.001). All experimental groups were associated with a significant difference on the radiographic and histological healing of apical periodontitis compared with its respective control group. CONCLUSION: Under the experimental conditions of this study, a larger apical enlargement protocol favoured a more rapid radiographic repair of apical periodontitis in rats after a 3-week follow-up.

Influence of apical foramen cleaning in the repair of periapical lesions / Influência da Limpeza do Forame Apical no Reparo de Lesões Periapicais

Objetivo: O presente estudo procurou acessar o efeito da limpeza do forame apical no reparo de lesões periapicais detectadas radiograficamente. Materiais e métodos: A amostra constituiu-se de 980 dentes selecionados de 25 de fevereiro de 1997 a 15 de março de 2005 que foram submetidos a tratamento endodôntico e exibiram lesões periapicais radiograficamente visíveis. A amostra foi então divididaem dois grupos: Grupo I, 402 tratamentos de canal em que a limpezado forame apical não foi realizada, e Grupo II, composto pelos 578 dentes restantes onde o procedimento foi realizado. Após um ano, os dentes foram clinica e radiograficamente avaliados.Resultados: No Grupo I, 360 canais (89,55%) não tiveram evidência de lesões periapicais, versus 521 (90,13%) no Grupo II. Presençaparcial dessas lesões foi observada em 23 canais (5,72%) no Grupo I versus 27 (4,67%) no Grupo II. O teste qui-quadrado de Pearson não demonstrou significância estatística entre os Grupos I e II (p=0,732).Conclusões: Estes achados sugerem que a limpeza do forame apical não é um determinante para o reparo de lesão periapical.

Aim: The present study sought to assessthe effect of apical foramen cleaningin the repair of periapical lesionsdetected by radiography. Methods:The sample comprised 980 teeth collected from 25 February 1997 to15 March 2005, which had been subjected to endodontic treatment and exhibited radiographically visibleperiapical lesions. The sample wasthen divided into two groups: Group I,402 root canal treatments in which cleaning of the apical foramen had notbeen performed, and Group II, composed of the remaining 578 rootcanal treatments where the procedure had been performed. After one year, the teeth were clinically and radiographically evaluated. Results: In Group I, 360 canals (89.55%) had no evidence of periapical lesions, versus 521 (90.13%) in Group II. Partial presence of thes e lesions was observedin 23 canals (5.72%) in Group I versus27 (4.67%) in Group II. No changes in images were observed in 19 (4.72%)canals in Group I and 30 in Group II. Pearson’s chi-square test showed nostatistically significant difference between the Groups I and II (p =0.732).Conclusions: These findings suggest thatforamen cleaning is not a determinantof periapical lesion repair.

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment: study in dogs

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35 percent of microbial leakage in the groups without plugs and 15 percent of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

O propósito deste trabalho foi avaliar a influência da infiltração coronária no reparo dos tecidos periapicais após obturação dos canais radiculares, preparo para pino e proteção ou não de um "plug" de cimento temporário. Quarenta canais de dentes de cães foram instrumentados e obturados pela técnica da condensação lateral ativa com cones de guta-percha e os cimentos Endomethasone e CRCS. Após preparo para pino os remanescentes do material obturador foram protegidos ou não com um "plug" do cimento temporário Coltosol e expostos ao meio oral por 90 dias. Decorrido este período, os animais foram mortos e os espécimes foram removidos e preparados para análises histomorfológica e histobacteriológica. Foi observado 35 por cento de casos de infiltração bacteriana nos grupos sem "plug" e 15 por cento nos grupos com "plug". Concluiu-se estatisticamente que o "plug" de Coltosol foi eficiente no controle da infiltração coronária de microorganismos (p=0,05), e que os cimentos CRCS e Endomethasone apresentaram resultados semelhantes (p>0,05).