Abstract The present study aimed to investigate the use of platelet-rich plasma (PRP) on tooth extraction sites in rats treated with bisphosphonates. Thirty Albinus Wistar male rats were administered 0.035 mg/kg zoledronic acid intravenously for 8 weeks, divided into four administrations with a 2-week interval between each application, after which their upper right central incisors were extracted to induce the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ). The samples were divided into the following two groups: Group 1 (G1) underwent marginal resection of BRONJ followed by the use of PRP, while Group 2 (G2) underwent resection of BRONJ but without the use of PRP. The treatment groups were evaluated after 14, 28, and 42 days. Clinical, microtomographic, microscopic, and immunohistochemical (IHC) evaluations were performed. Microtomography results revealed no significant difference between the groups (p <0.05) in any time period. Histomorphometric analysis showed increased bone formation over time for both groups (p < 0.001). G1 demonstrated a greater amount of new bone formation than G2 at 28 and 42 days (p < 0.001), with G1 presenting greater vascularization and a slightly higher VEGF expression. For both groups, RANKL/OPG expression levels were sufficient as a parameter for indicating the rate of bone remodeling in a previously treated area of osteonecrosis groups. Taken together, our findings indicated that the use of PRP improves the resolution process of BRONJ.

Abstract It is necessary to preserve height and thickness of the alveolar bone to facilitate rehabilitation with osteointegratable implants or simply to maintain bone integrity after extraction. Biomaterials associated with resorbable or non-resorbable membranes, when placed in the region of the socket, may contribute to avoid this unwanted reabsorption. Objective The objective of this study was to evaluate the distance of the crest of alveolar ridge to the cementoenamel junction (CEJ) of the lower second molars and the bone density of the third molar socket filled with Gen-Tech®, 5 years after an exodontia using cone beam computed tomography (CBCT) to visualize the central region of the sockets, without overlapping of the buccal and lingual cortical bones. Material and Methods A total of 12 individuals from an initial group of 39 patients submitted to extraction of the unruptured lower third molars and grafting of an association of inorganic bovine bone matrix, organic bovine bone matrix, collagen and bone morphogenetic proteins (BMP) (Gen-Tech®) on one side and the contralateral sockets filled only by clot, returned to control after 5 years, and were submitted to CBCT. The distance from the crest of alveolar bone to the CEJ and the bone density (BD) were measured using the i-CAT Vision Software. Results The results showed that the distance from the crest of alveolar bone to the CEJ in the control group was similar to that observed before the exodontia; in the experimental group, this distance was smaller. Considering the BD measurement, a significantly higher density was observed in the experimental group (p<0.05). Conclusion Part of the biomaterial was not absorbed and allowed the stability of the evaluated parameters after 5 years, being able to be used as a bone substitute in the socket.

The procedure of maxillary sinus lifting using autogenous bone was considered the reference standard choice for oral rehabilitation in cases of severe atrophic maxilla. However, it is not always a viable option, due to the limitations or morbidity caused by grafting techniques. This has led to the development of bone substitutes, which have been elaborated and improved. Choosing the best biomaterial becomes difficult due to the wide variety of bone substitutes. The aim of this article is to present some of these materials that are reported in the current scientific literature for maxillary sinus lifting.

El procedimiento de elevación del seno maxilar utilizando hueso autógeno se consideraba la opción estándar de oro para la rehabilitación oral en casos de maxilar atrófico grave. Sin embargo, no siempre es una opción viable, debido a las limitaciones o a la morbilidad causada por técnicas de injerto, lo que justifica la existencia de sustitutos óseos que han sido elaborados y mejorados. En cuanto a la amplia variedad de sustitutos óseos, se hace difícil la mejor elección de biomaterial. El objetivo de este informe es presentar una variedad de sustitutos óseos respetados en la literatura científica actual, usados en la elevación del seno maxilar.

ABSTRACT PURPOSE : To evaluate a modified experimental model for medication-related osteonecrosis of the jaw (MRONJ) through the upper right central incisor extraction followed by intravenous bisphosphonate administration. METHODS: Forty five rats underwent the upper right central incisor tooth extraction were divided in 2 groups: Group I - experimental group, 30 rats received an intravenous administration protocol of zoledronic acid 35μg/kg into the tail vein every two weeks, totalizing four administrations, during eight weeks of administration, previously the extraction, and Group II - control group, 15 rats didn't received any medication before extraction. The groups were subdivided in postoperative periods: 14/28/42 days. Clinical analysis and microtomography were performed to verify the presence of osteonecrosis. In addition, descritive histological analysis of hematoxylin-eosin stained sections was performed to evaluate the presence of osteonecrosis or necrotic foci. RESULTS: Twelve (40%) rats, from experimental group, showed clinical signs of MRONJ (p=0.005), however, all samples showed imaginologic findings like osteolysis and loss of integrity of the cellular walls (p≤0.001). Microscopic evaluation revealed osteonecrosis areas with microbial colonies and inflammatory infiltrate (p≤0.001). In the control group, all animals presented the chronology of a normal wound healing. CONCLUSIONS: The presence of medication-related osteonecrosis of the jaw after maxillary central incisor extraction in rats. This new experimental model may be considered an option for the study of MRONJ.

AbstractSurgically assisted rapid maxillary expansion (SARME) is the treatment of choice to adult patients even with severe transversal maxillary discrepancies. However, the adequate retention period to achieve the bone remodeling, thus assuring treatment stability, is controversial.Objective To evaluate the opening pattern and bone neoformation process at the midpalatal suture in patients submitted to surgically assisted (SARME) through cone beam computed tomography (CBCT).Material and Methods Fourteen patients were submitted to SARME through subtotal Le Fort I osteotomy. Both the opening pattern and the mean bone density at midpalatal suture area to evaluate bone formation were assessed pre- and post-operatively (15, 60 and 180 days) through CBCT.Results Type I opening pattern (from anterior to posterior nasal spine) occurred in 12 subjects while type II opening pattern (from anterior nasal spine to transverse palatine suture) occurred in 2 individuals. The 180-day postoperative mean (PO 180) of bone density value was 49.9% of the preoperative mean (Pre) value.Conclusions The opening pattern of midpalatal suture is more related to patients’ age (23.9 years in type I and 33.5 years in type II) and surgical technique. It was not possible to observe complete bone formation at midpalatal suture area at the ending of the retention period studied (180 days).

Fusão é a união de dois germes dentários em desenvolvimento, resultando numa única estrutura dentária, podendo ocorrer entre dois germes dentários normais ou entre o germe de um dente normal com um supranumerário. Dentes supranumerários são dentes adicionais à série normal e podem ocorrer em qualquer região da arcada dentária, entretanto, são mais comumente encontrados na maxila do que na mandíbula. O presente artigo ilustra um caso de fusão entre um terceiro molar mandibular e um dente supranumerário, onde foi realizada uma intervenção cirúrgica com o objetivo de remover os elementos dentários. Para complementar o diagnóstico, além da radiografia panorâmica, utilizou-se a técnica radiográfica de Donovan, mas, devido à proximidade do elemento dental com o ramo mandibular, não foi possível determinar um diagnóstico preciso de fusão. Sendo assim foi utilizada a Tomografia Computadorizada Volumétrica que fornece informações precisas e em três dimensões, possibilitando desta forma chegar ao diagnóstico de fusão e também auxiliando no planejamento cirúrgico.

Fusion is the union of two developing dental germs, resulting in a single large dental structure. It involve two normal dental germs or the germ of a normal tooth with a germ of a supernumerary one. Supernumerary teeth are additional teeth of the normal series which may occur in any region of the dental arch, althoug they are more common in the maxilla than in the mandible. This article presents a case of fusion between a third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan´s radiographic technique, but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography which provides precise three-dimensional information, was used to determinate the fusion diagnosis and also to help in the surgical planning.

OBJETIVO: Avaliar duas modalidades de tratamento da alveolite em ratos e discutir os primeiros achados de uma análise molecular neste modelo experimental. MÉTODOS: 84 ratos foram submetidos a uma extração dentária e foram divididos em quatro grupos: I- alvéolo não infectado (controle), II- alvéolo infectado sem tratamento, III- alvéolo infectado tratado com irrigação de iodeto de sódio a 2% e solução de peróxido de hidrogênio a 3%, IV- alvéolo infectado submetido à curetagem, irrigação com solução salina fisiológica e preenchimento com pasta a base de metronidazol. Os grupos foram subdivididos em períodos de sacrifício pós-operatório: 6/15/28 dias. Uma análise quantitativa e qualitativa microscópica foi realizada. Além disso, uma análise quantitativa foi realizada utilizando RealTimePCR para avaliar a expressão de genes no reparo alveolar: o colágeno tipo I / COL-I, o fator de crescimento endotelial vascular / VEGF, osteocalcina / OCN, fosfatase alcalina / ALP, fator de transcrição runt relacionados 2 / RUNX2 e fator de necrose tumoral alfa / TNF-α. RESULTADOS: O grupo I mostrou maior formação óssea, seguido pelos grupos IV, III, II, respectivamente. O grupo II apresentou maior infiltrado inflamatório e a cicatrização foi atrasada em comparação com outros grupos. Foi obtida uma correlação positiva entre a neoformação óssea e a expressão de OCN e RUNX2, infiltrado inflamatório com TNF-α e uma correlação negativa entre a neoformação óssea e TNF-α. CONCLUSÃO: Nenhuma diferença significativa foi encontrada entre os tratamentos.

PURPOSE: To evaluate two treatment modalities of dry socket in rats and to discuss the first findings of the molecular analysis in this experimental model. METHODS: 84 rats underwent a tooth extraction were divided in 4 groups: I-uninfected socket (control), II-infected socket without any treatment, III-infected socket treated with irrigation of 2% sodium iodide and 3% hydrogen peroxide solution, IV-infected socket submitted to curettage, irrigation with physiological saline solution and fulfilled with metronidazole paste as base. The groups were subdivided in postoperative sacrifice periods: 6/15/28 days. A quantitative and a qualitative microscopic analysis was performed. Also, a quantitative analysis was performed using a RealTimePCR to evaluate the genes expression in the wound healing: Collagen Type I/COL-I, vascular endothelial growth factor/VEGF, osteocalcin/OCN, alkaline phosphatase/ALP, runt-related transcription factor 2/RUNX2 and tumor necrosis factor alpha/TNF-α. RESULTS: The group I showed higher bone formation, followed by groups IV, III, II respectively. The group II presented higher inflammatory infiltrate and the wound healing was delayed compared with other groups. It was obtained a significant positive correlation between bone neoformation and the expression of OCN and RUNX2, inflammatory infiltrate with TNF-α and a negative correlation between bone neoformation and TNF-α. CONCLUSION: No significant difference was found between the treatments.

The pathogenesis of alveolitis is not well known and therefore experimental situations that mimic some features of this disease should be developed. OBJECTIVE: In this study, the evolution of the experimentally induced infection in rat sockets is characterized, which leads to clinical signs of suppurative alveolitis with remarkable wound healing disturbs. MATERIAL AND METHODS: Non-infected (Group I) and experimentally infected sockets in Rattus novergicus (Group II) were histometrically evaluated regarding the kinetics of alveolar healing. In addition, the characterization of the present bacteria in inoculation material and the serum levels of C-reactive protein (CRP) were performed. The detected species were Capnocytophaga ochracea, Fusobacterium nucleatum ss nucleatum, Prevotella melaninogenica, Streptococcus anginosus, Treponema socranskii and Streptococcus sanguis. RESULTS: All experimentally infected rats developed suppurative alveolitis, showing higher levels of CRP in comparison to those non-infected ones. Furthermore, infected rats presented a significant delayed wound healing as measured by the histometric analysis (higher persistent polymorphonuclear infiltrate and lower density of newly formed bone). CONCLUSION: These findings indicate that rat sockets with experimentally induced infection produced higher levels of serum CRP, showing the potential of disseminated infection and a disturb in the alveolar repair process in an interesting experimental model for alveolitis studies.

A falha primária de erupção é caracterizada pelo não irrompimento de um dente sem que haja impedimento mecânico ou que o dente esteja em posição anormal ou devido à causas sistêmicas. É um fenômeno raro e não foi associado com alterações do folículo dentário. Este relato descreve um caso de falha primária de erupção de um primeiro molar inferior direito permanente, localizado na base da mandíbula, que apresenta achados clínicos, radiográficos e microscópicos compatíveis com cisto folicular. O folículo pericoronário deste molar apresentou aspectos microscópicos de inflamação. Assim como os tecidos pericoronários dos dentes não irrompidos, a longo prazo, os folículos pericoronários dos dentes com falha primária de irrompimento têm o potencial para desenvolver cistos odontogênicos. Esta lesão provavelmente surgiu em associação com uma bolsa periodontal na mesial do segundo molar adjacente, caracterizando um cisto folicular inflamatório atípico. Este caso apresenta características etiológicas, radiográficas e microscópicas comuns nos cistos foliculares inflamatórios associados a dentes decíduos infectados, com exceção das infecções que alcançam o folículo. São discutidas ainda as controvérsias relativas à terminologia deste cisto.

Primary failure of eruption represents a cessation of tooth eruption before emergence not due to a physical barrier or abnormal position and has no systemic cause. This failure of tooth eruption is rare phenomenon and it has not been associated with alterations of dental follicle. This case report describes a permanent right first molar with primary failure of eruption at the inferior border of the mandible presenting microscopic, clinical and radiographic findings compatible with follicular cystic lesion. The follicular tissues of this molar showed microscopic aspects of inflammation. Thus, pericoronal tissues surrounding long-term unerupted teeth with primary failure of eruption has potential to develop into odontogenic cysts. The lesion presented herein probably arose in association with a periodontal pocket mesial to the adjacent second molar, representing an atypical inflammatory follicular cyst. This case shares etiological, radiological and microscopic features with the usual form of the inflammatory follicular cyst associated with infected primary teeth, except for the infection pathways reaching the tooth follicle. The controversies regarding the terminology for this cyst are discussed.

OBJETIVOS: avaliar a confiabilidade na identificação de marcadores observados em radiografias PA. METODOLOGIA: em 3 crânios humanos secos procedeu-se à instalação de aparelhos expansores do tipo Hyrax, nos quais adaptaram-se marcadores nos acessórios ortodônticos. RESULTADOS: a comparação estatística dos 27 cefalogramas confeccionados revelou para as medidas angulares valores dos erros com pequenas variações, entretanto os menores erros foram encontrados para as medidas lineares entre os marcadores. Deste modo, conclui-se que a pouca variabilidade na identificação dos marcadores demonstrou sua confiabilidade para o uso em estudo com telerradiografias PA.Os erros para as medias angulares atribui-se às dificuldades na determinação de estruturas anatômicas. CONCLUSÃO: os marcadores avaliados neste estudo parecem prestarem-se como estruturas confiáveis em telerradiografias PA utilizadas em pesquisas longitudinais.

AIM: to evaluate the reliability in the identification of the markers observed in frontal Cephalometric x-rays. METHODS: in 3 dry humans skull were adapted expansor appliances, in which markers were attached at orthodontics brackets and tubes. RESULTS: the statistical comparison of the 27 postero-anterior cephalograms revealed that the angular measures showed small variations; however the smallest error were for the lineal measures among the markers. CONCLUSION: the markers demonstrated its reliability for the use in longitudinal researches with frontal cephalometric x-rays.

A erupção ectópica e a impacção de caninos superiores são problemas bastante comuns na população. A excelência do tratamento ortodôntico traduz-se na correção da oclusão, harmonia do sorriso, saúde periodontal e estabilidade pós-tratamento. Para obtermos tais condições, a manutenção dos caninos é fundamental. Portanto, o objetivo deste estudo foi avaliar radiograficamente a localização de caninos superiores não irrompidos utilizando-se radiografias panorâmicas. Foram selecionadas setenta radiografias panorâmicas de pacientes com impacção uni ou bilateral de caninos, candidatos a tratamento cirúrgico. Para determinação da posição espacial dos caninos superiores não irrompidos foram selecionados métodos descritos na literatura e uma avaliação proposta neste trabalho. A localização de caninos não irrompidos é fundamental para estabelecer o plano de tratamento, auxiliando no acesso cirúrgico e na direção das forças ortodônticas a serem aplicadas no dente impactado. Os pacientes que tiveram suas radiografias utilizadas neste estudo serão tratados pelas disciplinas de Ortodontia e Cirurgia, com exodontia do canino ou exposição cirúrgica para colagem do dispositivo de tracionamento associada ao tratamento ortodôntico corretivo.

Ectopic eruption and the impaction of upper canines are problems quite commonly presented by the population. An excellent orthodontic treatment encompasses occlusal correction, smile harmony, periodontal health and posttreatment stability. Such conditions can be obtained upon the due maintenance of the canines, therefore, the aim of this study is to assess the radiographic localization of non-erupted upper canines using panoramic radiographs. In this study, seventy panoramic radiographs of patients presented with uni or bilateral canine impaction, applying for surgical treatment, were selected. Methods described in the literature and an evaluation proposed in this work were chosen to determine the spatial position for non-erupted upper canines. The localization of non-erupted canines is fundamental to establish the treatment plan, aiding in the surgical access and in the direction of orthodontic forces to be applied on the impacted tooth. The patients whose radiographs were utilized in this study will be treated at the Orthodontics and Surgery Departments, by means of surgeries for canine exodontics or surgical exposure for the bonding of a wire traction device, associated with corrective orthodontic treatment.