Evaluation of Microleakage by Gas Permeability and Marginal Adaptation of MTA and BiodentineTM Apical Plugs: In Vitro Study / Evaluación de la microfiltración por permeabilidad de gas y adaptación marginal de tapones apicales de MTA y BiodentineTM: Estudio in vitro

Abstract The endodontic treatment of teeth with incomplete development is always a complex task. Nowadays, biomaterials such as bioceramics offers promising clinical evidence that supports its use. However, the standardization of its use for apexification purpose still needs a deeper understanding of the materials' behavior. The aim of this investigation was to evaluate the marginal adaptability and microleakage by gas permeability of MTA and Biodentine™ apical plugs in an in vitro model. Materials and methods: Twenty- four single rooted human teeth were selected according to previously stablished inclusion criteria. All samples were prepared obtaining standard cylindrical internal canals with a diameter of 1.3 mm. Root canals were gently rinsed using 5.25% sodium hypochlorite and EDTA 17%. The apical 3mm and remaining coronal dental structure were sectioned to obtain 10mm roots. Roots were randomly assigned to 3 different groups as follows: GROUP A: MTA (n=10), GROUP B: Biodentine™ (n=10) and Group C: Control (positive n=1, negative n=3). MTA and Biodentine™ were prepared according to manufacturer's indications, and apical plugs of 4mm were passively placed in the correspondent teeth. All samples were stored in saline solution for 7 days at 37°C before evaluation. Samples were mounted in cylindrical sample-holders using epoxy resin. Microleakage was evaluated with an automatic permeability detector that calculates nitrogen diffusion between the material-root interphase. After microleakage evaluation, the samples were recovered and analyzed by scanning electron microscopy (SEM). Microleakage results were analyzed using Chi-square and adaptation was evaluated with a descriptive analysis. Results: None of the evaluated materials completely avoided the nitrogen microleakage (positive leakage of 10% and 20% of samples for MTA and Biodentine™ respectively); with no statistical significant difference between groups (p=0.527). All apical plugs showed good adaptation under SEM, at 30x, 200x, 1000x and 2500x; with microscopical structures similar to previous reports. Conclusions: Both bioceramics behave similar when used as apical barriers to avoid permeability, with acceptable marginal adaptation. Further in vivo studies are needed to validate these results.

Resumen El tratamiento endodóntico de dientes con desarrollo incompleto es siempre una tarea compleja. Hoy en día, biomateriales como las biocerámicas ofrecen una evidencia clínica prometedora que apoya su uso. Sin embargo, la estandarización de su uso para fines de apexificación todavía necesita una comprensión más profunda del comportamiento de los materiales. El objetivo de esta investigación fue evaluar la adaptabilidad marginal y microfiltración por permeabilidad de gas de los tapones apicales de MTA y Biodentine™ en un modelo in vitro. Materiales y métodos: Veiticuatro dientes humanos uniradiculares fueron seleccionados meticulosamente según criterios de inclusión previamente establecidos. Todas las muestras fueron preparadas con canales cilíndricos internos estandarizados de 1,3 mm de diámetro. Los conductos radiculares fueron gentilmente lavados con hipoclorito de sodio al 5,25% y EDTA al 17%. La estructura dental apical de 3 mm y la coronal restante se seccionó para obtener raíces de 10 mm de longitud. Las raíces se asignaron aleatoriamente a 3 grupos diferentes de la siguiente manera: GRUPO A: MTA (n = 10), GRUPO B: Biodentine™ (n = 10) y Grupo C: Control (n = 1 positivo, n = 3 negativos). El MTA y Biodentine™ se prepararon de acuerdo con las indicaciones de los fabricantes, y se colocaron pasivamente los tapones apicales de 4 mm en los dientes correspondientes. Todas las muestras se almacenaron en solución salina durante 7 días a 37ºC antes de la evaluación. Las muestras se montaron en porta-muestras cilíndricos utilizando resina epóxica. La microfiltración se evaluó con un detector de permeabilidad automática que calcula la difusión de nitrógeno entre la interfase material-raíz. Después de la evaluación de microfiltración, las muestras fueron recuperadas y analizadas por microscopía electrónica de barrido (SEM). Los resultados de microfiltración se analizaron utilizando una prueba estadística de Chi-cuadrado y la adaptación se evaluó con un análisis descriptivo. Resultados: Ninguno de los materiales evaluados evitó completamente la microfiltración de nitrógeno (fuga positiva de 10% y 20% de muestras para MTA y Biodentine™, respectivamente); sin diferencias estadísticamente significativas entre los grupos (p = 0,527). Todos los tapones apicales mostraron una buena adaptación bajo SEM, a 30x, 200x, 1000x y 2500x; con morfologías similares a las previamente reportadas. Conclusiones: ambas biocerámicas se comportan de forma similar cuando se usan como barreras apicales para evitar la permeabilidad de gas, con adaptación marginal aceptable. Se necesitan más estudios in vivo para validar estos resultados.

Prevalence of Treponemaspp. in endodontic retreatment-resistant periapical lesions

This study investigated the presence of the Treponema species in longstanding endodontic retreatment-resistant lesions of teeth with apical periodontitis, the association of this species with clinical/radiographic features, and the association among the different target species. Microbial samples of apical lesions were collected from twenty-five adult patients referred to endodontic surgery after unsuccessful root canal retreatment. Nested-PCR and conventional PCR were used for Treponema detection. Twenty-three periradicular tissue samples showed detectable levels of bacterial DNA. Treponema species were detected in 28% (7/25) of the cases. The most frequently detected species were T. socranskii (6/25), followed by T. maltophilum (3/25), T. amylovorum (3/25), T. lecithinolyticum(3/25), T. denticola (3/25), T. pectinovorum (2/25) and T. medium(2/25). T. vicentii was not detected in any sample. Positive statistical association was found between T. socranskiiand T. denticola,and between T. maltophilumand T. lecithinolyticum. No association was detected between the presence of any target microorganism and the clinical or radiographic features. Treponemaspp.are present, in a low percentage, in longstanding apical lesions from teeth with endodontic retreatment failure.

Effect of MTA-based sealer on the healing of periapical lesions

Some manufacturers have recently added specific components to improve the ease of handling and insertion material properties of MTA in order to create MTA-based sealers. Objective The aim of this study was to evaluate the healing of periapical lesions in canine teeth after a single session of endodontic treatment with MTA Fillapex® compared with Sealapex® or Endo-CPM-Sealer®. Material and Methods Sixty-two root canals were performed on two 1-year-old male dogs. After coronal access and pulp extirpation, the canals were exposed to the oral cavity for 6 months in order to induce periapical lesions. The root canals were prepared, irrigated with a solution of 2.5% sodium hypochlorite and filled with gutta-percha and different sealers, according to the following groups: 1) Sealapex®; 2) Endo-CPM-Sealer®; and 3) MTA Fillapex®. Some teeth with periapical lesions were left untreated for use as positive controls. Healthy teeth were used as negative controls. After 6 months, the animals were sacrificed and serial sections from the roots were prepared for histomorphologic analysis and stained with hematoxylin and eosin and the Brown and Brenn technique. The lesions were scored according to pre-established histomorphologic parameters and the scores statistically analyzed using the Kruskal-Wallis test. Results All 3 materials produced similar patterns of healing (p>0.05); in particular, persistent inflammation and absence of complete periapical tissue healing were consistently noted. Conclusions Preparation of the infected root canals followed by filling with the materials studied was insufficient to provide complete healing of the periapical tissues. .

Tissue reaction to Endométhasone sealer in root canal fillings short of or beyond the apical foramen

OBJECTIVE: This study evaluated the response of periapical tissues to the endodontic sealer Endométhasone in root canal fillings short of or beyond the apical foramen. MATERIAL AND METHODS: Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to obtain a main apical foramen, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramen by the lateral condensation of gutta-percha and Endométhasone, originating 2 experimental groups: G1: Endométhasone/short of the apical foramen; G2: Endométhasone/beyond the apical foramen. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown & Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramen of the main root canal and apical opening of accessory canals, apical cementum resorption, intensity of the inflammatory infiltrate, presence of giant cells and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (p=0.05). RESULTS: Comparing the 2 groups, the best result (p<0.05) was obtained with root canal filling with Endométhasone short of the apical foramen but a chronic inflammatory infiltrate was present in all specimens. CONCLUSIONS: Limiting the filling material to the root canal space apically is important to determine the best treatment outcome when Endométhasone is used as sealer.

A comparative evaluation of healing with a computed tomography scan of bilateral periapical lesions treated with and without the use of platelet-rich plasma.

Periradicular surgery aims to achieve complete wound healing and regeneration of the periodontal unit. Platelet-rich plasma (PRP) is a platelet concentrate that is widely used to promote tissue healing, and bone induction through its various growth factors has been used in this study. This case report describes the use of PRP unilaterally in a bilateral periapical lesion in the same patient. The site treated with PRP showed better healing than the untreated site. This was confirmed with computed tomography (CT) scan readings. It was hypothesized that PRP could promote tissue regeneration and alveolar bone repair.

Inmunodetección de metaloproteinasas de matriz extracelular (MMPs)-2, -9, -13 y -14 en lesiones apicales asociadas con periodontitis apical asintomática / Immunodetection of matrix metalloproteinases (MMPs)-2, -9, -13 and -14 in periapical lesions associated with asymptomatic apical periodontitis

La periodontitis apical asintomática (PAa) es una patología infecciosa caracterizada por destrucción ósea perirradicular asociada a un proceso inflamatorio crónico y producción de mediadores inflamatorios, entre los cuales se encuentran las metaloproteinasas de matriz extracelular (MMPs). Entre éstas, las MMPs-13, -14, -2 y -9, son producidas por el tejido óseo y degradan sinérgicamente el colágeno tipo I, principal componente de los tejidos periodontales, y gelatina, producto de la degradación y desnaturación del colágeno. El objetivo de este estudio fue determinar el patrón de expresión de las MMPs-2, -9, -13 y -14 en granulomas periapicales (GPAs), quistes radiculares inflamatorios (QRIs) y ligamento periodontal sano (LS). Materiales y Métodos: Se seleccionaron 12 pacientes con diagnóstico clínico de PAa e indicación de exodoncia a partir de los cuales se obtuvieron biopsias de lesiones periapicales (LPAs). Como controles, se seleccionaron 7 individuos con indicación de exodoncia de premolares por ortodoncia, obteniéndose biopsias de LS. Se efectuó el diagnóstico anátomo-patológico de los especímenes y se caracterizó la expresión de las MMPs en estudio mediante inmunohistoquímica. Resultados: Las MMPs en estudio sólo se detectaron en GPAs y QRIs, y se inmunolocalizaron principalmente en el infiltrado inflamatorio de éstos. Adicionalmente, la MMP-2 se identificó en fibroblastos del tejido conectivo. Conclusiones: MMPs-2, -9, -13 y -14 se expresan predominantemente en el infiltrado inflamatorio de las LPAs y no en LS, y por tanto se sugiere la participación de estos mediadores en la patogénesis de la PAa.

Asymptomatic apical periodontitis (aAP) is an infectious disease characterized by perirradicular bone destruction associated with chronic inflammation and release of inflammatory mediators, such as matrix metalloproteinases (MMPs). MMPs-13, -14 and -2, -9 are bone-expressed enzymes that can synergistically degrade collagen I, the main component of periodontal extracellular matrix, and gelatin, the product of degradation and denaturation of collagen. The aim of this study was to characterize the expression pattern of MMPs-2, -9, -13, and -14 in periapical granulomas (PGs), radicular cysts (RCs) and healthy periodontal ligament (PDL). Materials and Methods: Individuals with clinical diagnosis of aAP and indication of extraction were selected (N=12), and biopsies of periapical lesions (PLs) were obtained. For controls, 7 subjects with indication of premolar extraction for orthodontic reasons were selected, and PDL biopsies were obtained. Samples were diagnosed by anatomopathological examination and immunohistochemical staining was carried out to characterize MMPs expression. Results: MMPs-2, -9, -13 and -14 detection was limited to PLs and were localized mainly to inflammatory infiltrate on both, PGs and RCs. Additionally, MMP-2 was immunolocalized to fibroblasts from the connective tissue. Conclusions: Whereas MMPs-2, -9, -13 and -14 were not detected in healthy periodontal ligament, they were highly expressed on inflammatory infiltrate from PGs and RCs, suggesting a role of these mediators in aAP pathogenesis.

Histopathological evaluation of root canal filling materials for primary teeth

This study aimed to assess the response of apical and periapical tissues of dogs' teeth after root canal filling with different materials. Forty roots from dogs' premolars were prepared biomechanically and assigned to 4 groups filled with: Group I: commercial calcium hydroxide and polyethylene glycol-based paste (Calen®) thickened with zinc oxide; Group II: paste composed of iodoform, Rifocort® and camphorated paramonochlorophenol; Group III: zinc oxide-eugenol cement; Group IV: sterile saline. After 30 days, the samples were subjected to histological processing. The histopathological findings revealed that in Groups I and IV the apical and periapical regions exhibited normal appearance, with large number of fibers and cells and no resorption of mineralized tissues. In Group II, mild inflammatory infiltrate and mild edema were observed, with discrete fibrogenesis and bone resorption. Group III showed altered periapical region and thickened periodontal ligament with presence of inflammatory cells and edema. It may be concluded that the Calen paste thickened with zinc oxide yielded the best tissue response, being the most indicated material for root canal filling of primary teeth with pulp vitality.

O objetivo deste estudo foi avaliar a resposta dos tecidos apicais e periapicais de dentes de cães, após obturação dos canais radiculares com diferentes materiais indicados para dentes decíduos. Foram utilizados pré-molares de cães, totalizando 40 raízes que, após pulpectomia e preparo biomecânico, foram divididas em 4 grupos, nos quais os canais radiculares foram obturados com os seguintes materiais: Grupo I - pasta comercial composta de hidróxido de cálcio e polietileno glicol 400 (Calen®) espessada com óxido de zinco; Grupo II - pasta composta de iodofórmio, Rifocort® e paramonoclorofenol canforado; Grupo III - cimento de óxido de zinco e eugenol; e Grupo IV - solução salina. Decorridos 30 dias, as peças foram submetidas ao processamento histológico. De acordo com os resultados da análise histopatológica observou-se que nos Grupos I e IV as regiões apical e periapical apresentaram aspecto de normalidade, com grande número de fibras e células e ausência de reabsorção dos tecidos mineralizados. No Grupo II observou-se infiltrado inflamatório e edema leves, com discreta fibrogênese e reabsorção óssea. O Grupo III apresentou alteração na região periapical e ligamento periodontal ampliado, com presença de células inflamatórias e edema. Os resultados obtidos permitiram concluir que a pasta Calen espessada com óxido de zinco apresentou a melhor resposta tecidual, sendo a mais indicada para a obturação de canais radiculares de dentes decíduos com vitalidade pulpar.

Response of the periapical tissue of dogs' teeth to the action of citric acid and EDTA

The purpose of this study was to analyze the inflammatory response of dog's periapical tissues to 17 percent trisodium EDTA salt (pH 8.0) and 1 percent citric acid (pH 2.0). Saline was used as a control. Six adult dogs were used as the biological model of the study. The experimental units comprised 56 roots of mandibular molars (first and second) and premolars (first, second and third). After coronal opening, pulpectomy and root canal instrumentation were performed using the above-mentioned irrigating solutions. After 24 and 48 hours, the animals were euthanized and the teeth and their supporting tissues were removed and histologically processed. The sections were stained with hematoxylin and eosin and analyzed histopathologically with a light microscope at x100 magnification. The histological analysis focused on the occurrence of acute inflammatory response. The presence of swelling, vasodilatation and inflammatory cells were evaluated and the degree of inflammation was determined for each case. Data were analyzed by Fisher's exact test using the SPSS software with a confidence interval of 95 percent (p<0.05). 17 percent EDTA and 1 percent citric acid caused inflammatory responses in dog's periapical tissues with no significant differences to each other or to saline (control) at either the 24-hour (p=0.482) or 48-hour (p=0.377) periods. It may be concluded that the inflammatory response was of mild intensity for the tested substances.

Influência da espessura dos tecidos moles no diagnóstico de lesões ósseas produzidas / Influence of the soft tissue thickness in the diagnosis of produced bone lesions

O objetivo deste trabalho foi avaliar a influência da espessura dos tecidos moles na capacidade de diagnóstico de lesões ósseas periapicais. Para isso, foram utilizados segmentos posteriores de mandíbulas de suínos que foram dissecadas em três planos teciduais (osso, músculo e pele). Foram confeccionados cavidades ósseas na região periapical por meio de brocas esféricas. Essas cavidades foram aumentadas gradativamente e, em seguida, radiografadas com os tecidos posicionados. As imagens foram avaliadas por cinco avaliadores, e, após a análise estatística, pôde-se observar que a espessura dos tecidos não influenciou o diagnóstico das lesões porém este foi melhor para as lesões com, no mínimo, 1,5 mm de diâmetro.

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).

Comparative study of MTA and other materials in retrofilling of pulpless dogs' teeth

O presente estudo in vivo comparou os efeitos do agregado de trióxido mineral (MTA), IRM, Super EBA e OZE na consistência de massa de vidraceiro, usados como material para obturação retrógrada, no processo de reparo dos tecidos periapicais de dentes despulpados de cães submetidos à técnica de retrobturação convencional. Vinte e quatro pré-molares obtidos de três cães foram usados. Na primeira intervenção, os animais foram anestesiados, e a abertura coronária e a pulpectomia foram realizadas. Os canais radiculares foram mantidos abertos ao meio oral por 180 dias para induzir a formação de lesão periapical. Após a remoção cirúrgica das lesões com curetas, 2 mm apicais da raiz foram seccionados perpendicularmente ao longo eixo do dente e uma cavidade apical foi preparada com broca esférica em baixa-rotação. As cavidades ósseas foram irrigadas e secas, e as cavidades apicais obturadas com MTA, IRM, Super EBA e OZE na consistência de massa de vidraceiro. As cavidades ósseas foram passivamente preenchidas com sangue e os retalhos suturados. As aberturas coronárias foram limpas e seladas duplamente com OZE e amálgama. Após 180 dias, os animais foram sacrificados por super-dosagem de anestésico, a maxila e a mandíbula foram removidas e as peças processadas para análise histomorfológica. Os dados foram avaliados cegamente com base nos vários eventos histomorfológicos e os escores obtidos foram analisados estatisticamente usando o teste Kruskal Wallis. Nenhuma diferença estatisticamente significante foi observada entre MTA, Super EBA e IRM (p>0,005). Entretanto, o OZE teve influência negativa significantemente maior no reparo apical (p<0,005). Estes resultados indicam que MTA, Super EBA e IRM tiveram efeitos histopatológicos similares entre eles e melhor performance que o OZE utilizado na consistência de massa de vidraceiro. Além disso, somente o MTA estimulou a deposição de tecido duro em contato direto com o material retrobturador, mesmo quando inserido sob condições críticas.

Análise histológica da reparaçäo apical e periapical pós-tratamento endodôntico de dentes de cäes com reaçäo periapical crônica induzida, em funçäo do curativo de demora com Calen/PMCC ou Calasept, e da obturaçäo do canal radicular com Sealapex ou AH Plus / Histological analysis of endodontic post-treatment periapical and apical reparation of dog's teeth with induced periapical periodontitis, in function of temporary dressing with Calen/PMCC or Calasept, and of root canal filling with Sealapex or AH Plu

Foram utilizados 78 canais radiculares de dentes de 6 cäes, sem vitalidade pulpar e com reaçäo periapical crônica induzida. Após o preparo biomecânico utilizando o hipoclorito de sódio a 5,25 por cento como soluçäo irrigadora, os canais radiculares receberam as pasta à base de hidróxido de cálcio Calen com PMCC ou Calasept como curativo de demora por 30 dias. Decorrido este período, os canais radiculares foram obturados com guta-percha e o cimento endodôntico Sealapex ou guta-percha e AH Plus empregando-se a técnica de condensaçäo lateral da guta-percha e tiveram suas aberturas coronárias seladas com amálgama. Após o período de 360 dias, os animais foram sacrificados por sobredose anestésica e as peças submetidas ao processamento histológico. Os cortes histológicos com 6 µm de espessura foram corados pela Hematoxilina e Eosina, sendo submetidos à microscopia óptica para a avaliaçäo do reparo apical e periapical. Os resultados demonstraram que o grupo Calasept AH Plus apresentou os piores resultados histopatológicos, com significância estatística quanto ao infiltrado inflamatório, selamento apical biológico, reabsorçäo óssea e espessura do ligamento periodontal. O cimento Sealapex mostrou melhores resultados histopatológicos do que o AH Plus. A pasta Calen/PMCC comportou-se ecleticamente bem com ambos os cimentos obturadores, e a pasta Calasept mostrou sugestivamente sinergismo com o Sealapex e antagonismo com o AH Plus

Comportamento dos tecidos periapicais após o tratamento endodôntico em uma ou em duas sessöes: influência do cimento obturador / Behavior of the periapical tissue after endodontical treatment in one or two sessions: influence of the sealing cement

Dentes de cäes foram submetidos à pulpectomia em uma e em duas sessöes e obturados com o cimento de óxido de zinco e eugenol, em diferentes proporçöes pó-líquido. A avaliaçäo histológica mostrou näo haver diferenças significantes entre os tratamentos em uma ou em duas sessöes na grande maioria dos espécimes e que o cimento obturador, mesmo em diferentes proporçöes pó-líquido, näo impediu o reparo. As obturaçöes realizadas a aproximadamente 1 mm do forame permitiram, quase sempre, o selamento parcial do forame por significativa deposiçäo de cemento

Estudo histológico da regiäo periapical de molares de ratos / Histological study of periapical region of molars of rats

O presente estudo teve o própósito de verificar histologicamente a reaçäo inflamatória pós-pulpectomia em dentes de ratos, quando säo aplicados diferentes corticosteróides isoladamente e em iguais concentraçöes. As seguintes drogas foram testadas: hidrocortisona, prednisolona e dexametasona a 2% em soro fisiológico. os resultados evidenciaram que a utilizaçäo da substância corticosteróide näo acompanhada de um anti-microbiano, levou a necrose pulpar com formaçäo de abcesso periapical e evoluçäo para quadros de osteomielite, sendo possível verificar a presença de colônias bacterianas na regiäo periapical

La oligodoncia: estudio de 500 historias clínicas / Oligodontia: study of 500 clinical histories

Se estudiaron 500 historias clínicas de pacientes tratados en el Departamento de Ortodoncia de la Facultad de Estomatología, a las mismas se les revisó el estudio periapical para detectar los dientes ausentes congénitamente. Se encontró que el 5,8 de los casos estudiados presentaba oligodoncia y que el orden de frecuencia de la misma es distinto al planteado por los autores extranjeros consultados. Se halló que la oligodoncia es más frecuente en la mandibula y que no existe predominio en ningún sexo