Neo-osteogenesis using an intentionally exposed polypropylene membrane after tooth extraction versus guided bone regeneration technique: a single-blind randomized controlled trial / Neo-osteogénesis utilizando una membrana de polipropileno expuesta intencionalmente después de la extracción del diente versus técnica de regeneración ósea guiada: ensayo clínico aleatorizado ciego / Neo-osteogênese utilizando uma membrana de polipropileno exposta intencionalmente após extração dentária versus técnica de regeneração óssea guiada: ensaio clínico randomizado e cego

Introduction: The intentionally exposed polypropylene (PP) membrane has been proposed for guided bone regeneration (GBR) of the alveo lar bone after extraction; however, there are biological limitations to this proposal. This study aimed to describe the effects of the PP membrane on neo-osteogenesis after tooth extraction, comparing to intentionally ex posed and primary soft tissue coverage techniques. Methodology: This clinical trial followed the TIDieR checklist and guide. Clinical and histo logical parameters of alveolar repair were compared between groups: 1 (control group), without regenerative procedure; 2, GBR; and 3, inten tionally exposed membrane. Results: Group 3 showed slight effect on the quality of new bone, compared to the control group. Although the GBR was underestimated by the early exposure of the membrane, alveo lar repair and newly formed bone were superior to the other groups. Poly propylene membrane intentionally exposed compromised the volume density of the immature and mineralized bone matrix, the osteoblast and osteocyte count, and stimulated the granulation tissue formation and local inflammatory infiltrate. Conclusions: Despite the exposure of the PP membrane in GBR, this technique improved the quality of new bone and alveolar repair compared to the surgical technique of intentional exposure and alveolus only sutured.

RESUMEN Introducción: La membrana de polipropileno (PP) intencionalmente expuesta ha sido propuesta para la regeneración ósea guiada (GBR) del hueso alveolar después de la extracción; sin embargo, existen limitaciones biológicas a esta propuesta. Este estudio tuvo como objetivo describir los efectos de la membrana de PP en la neo-osteogénesis después de la extracción del diente, en comparación con las técnicas de cobertura de tejido blando primarias y expuestas intencionalmente. Metodología: Este ensayo clínico siguió la lista de verificación y la guía TIDieR. Se compararon los parámetros clínicos e histológicos de la reparación alveolar entre los grupos: 1 (grupo control), sin procedimiento regenerativo; 2, GBR; y 3, membrana expuesta intencionalmente. Resultados: el grupo 3 mostró un ligero efecto sobre la calidad del hueso nuevo, en comparación con el grupo de control. Aunque la GBR fue subestimada por la exposición temprana de la membrana, la reparación alveolar y el hueso neoformado fueron superiores a los otros grupos. La membrana de polipropileno expuesta intencionalmente comprometió la densidad de volumen de la matriz ósea inmadura y mineralizada, el recuento de osteoblastos y osteocitos, y estimuló la formación de tejido de granulación y el infiltrado inflamatorio local. Conclusiones: A pesar de la exposición de la membrana de PP en GBR, esta técnica mejoró la calidad del hueso nuevo y la reparación alveolar en comparación con la técnica quirúrgica de exposición intencional y alvéolo solo suturado.

Introdução: A membrana de polipropileno (PP) intencionalmente exposta tem sido proposta para regeneração óssea guiada (ROG) do osso alveolar após exodontia; no entanto, existem limitações biológicas a esta proposta. Este estudo teve como objetivo descrever os efeitos da membrana de PP na neo-osteogênese após a extração dentária, comparando com as técnicas de exposição intencional e cobertura primária de tecidos moles. Metodologia: Este ensaio clínico seguiu a lista de verificação e o guia TIDieR. Parâmetros clínicos e histológicos do reparo alveolar foram comparados entre os grupos: 1 (grupo controle), sem procedimento regenerativo; 2, GBR; e 3, membrana intencionalmente exposta. Resultados: O Grupo 3 apresentou leve efeito na qualidade do novo osso, em comparação com o grupo controle. Embora o GBR tenha sido subestimado pela exposição precoce da membrana, o reparo alveolar e o osso neoformado foram superiores aos outros grupos. A exposição intencional da membrana de polipropileno comprometeu a densidade volumétrica da matriz óssea imatura e mineralizada, a contagem de osteoblastos e osteócitos e estimulou a formação de tecido de granulação e infiltrado inflamatório local. Conclusões: Apesar da exposição da membrana PP na ROG, esta técnica melhorou a qualidade do novo osso e da reparação alveolar em comparação com a técnica cirúrgica de exposição intencional e alvéolo apenas suturado.

Histopathological evaluation of the effect of Salvadoria persica and Nigella sativa on the healing of tooth extraction socket in animal

To assess the effects of Salvadoria persica and Nigella sativa combination in tooth socket healing after extraction that can be a novel remedy for tooth extraction socket. Methods: Forty rabbits were included in this study, divided into two groups (control and experimental) with 20 rabbits. Upper right central incisors were extracted for all animals, the tooth sockets of the experimental group were dressed using an admix of Salvadoria persica and Nigella sativa immediately after irrigation with normal saline. In contrast, the extraction sockets of the control group were left without dressing. Biopsies were taken after euthanizing the animals at 1, 3, 7, and 14 days after treatment, histological examination was done for the samples at the given periods respectively. Results: On day 1 post-treatment, histological examination of the experimental group sections showed less acute inflammatory reaction than the control group. This continued to be reduced until the seventh day. The amount of granulation tissue formation was more in the experimental group along the different periods of the study, while new bone formation was observed after 1 week as woven bone, increased after 2 weeks and appeared as woven and lamellar bone in both experimental and control groups. Conclusions: A mixture of Salvadoria persica and Nigella sativa has an anti-inflammatory effect and accelerate bone healing by stimulating bone formation in the tooth extraction socket

The effect of scaffold hydroxyapatite derived from portunus pelagicus shell on the expression of fibroblast growth factor-2 (fgf-2) and bone morphogenetic proteins-2 (bmp -2) in the extraction sockets of cavia cobaya / El efecto del scaffold de hidroxiapatita derivada de portunus pelagicus sobre la expresión del factor de crecimiento de fibroblastos-2 (FGF-2) y las proteínas morfogenéticas óseas-2 (BMP-2) en los alvéolos dentarios de cavia cobaya

Objetive: To determine the expression of Fibroblast Growth Factor (FGF)-2 and Bone Morphogenetic Protein (BMP)-2 after application of scaffold hydroxyapatite from Rajungan crab shell (Portunus pelagicus) in the tooth extraction socket of Cavia cobaya. Material and Methods: This study used a post-test only control group design with 28 Cavia cobaya separated into two groups, control and treatment group. The left mandibular incisor was extracted, and socket preservation was conducted. A hydroxyapatite graft derived from crab shells was mixed with gelatin and eventually turned into a scaffold, which was afterward put into the extraction socket. After 7 days and 14 days, each group was terminated and examined using immunohistochemical staining to observe the expression of FGF-2 and BMP-2. One-Way Anova and Tukey HSD were used to examine the research data. Results: FGF-2 and BMP-2 expressions were observed higher in the group that received hydroxyapatite scaffold at the post-extraction socket than those in the group that did not receive hydroxyapatite scaffold. Conclusion: The application of a hydroxyapatite scaffold from Rajungan crab shell (Portunus pelagicus) to the tooth extraction socket can increase FGF-2 and BMP-2 expression.

Objetivo: Determinar la expresión del factor de crecimiento de fibroblastos (FGF)-2 y la proteína morfogenética ósea (BMP)-2 después de la aplicación de hidroxiapatita de andamio de caparazón de cangrejo Rajungan (Portunus pelagicus) en el alvéolo de extracción dental de Cavia cobaya. Material y Métodos: Este estudio utilizó un diseño de grupo de control solo posterior a la prueba con 28 Cavia cobaya separados en dos grupos, grupo de control y grupo de tratamiento. Se extrajo el incisivo mandibular izquierdo y se realizó la preservación del alvéolo. Un injerto de hidroxiapatita derivado de caparazones de cangrejo se mezcló con gelatina y se convirtió en un andamio, que luego se colocó en el alvéolo de extracción. Después de 7 días y 14 días, se terminó cada grupo y se examinó mediante tinción inmunohistoquímica para observar la expresión de FGF-2 y BMP-2. Se utilizaron One-Way Anova y Tukey HSD para examinar los datos de la investigación. Resultados: Las expresiones de FGF-2 y BMP-2 se observaron más altas en el grupo que recibió la estructura de hidroxiapatita en el alvéolo posterior a la extracción que en el grupo que no recibió la estructura de hidroxiapatita. Conclusión: La aplicación de un andamio de hidroxiapatita de caparazón de cangrejo Rajungan (Portunus pelagicus) al alvéolo de extracción dental puede aumentar la expresión de FGF-2 y BMP-2.

Regeneração óssea guiada de alveolos de extração dentária - uma revisão / Guided bone regeneration of alveoli tooth extraction - a review

O osso é um tecido conjuntivo especializado, vascularizado e dinâmico que se modifica ao longo do organismo. Quando lesado, possui uma capacidade única de regeneração e reparação sem a presença de cicatrizes, mas em algumas situações devido tamanho do defeito ósseo não se regenera por completo. Assim, se faz necessária a realização de procedimentos de regeneração óssea guiada. Para isso, o implantodontista deve conhecer as bases biológicas da regeneração óssea guiada alveolar e suas indicações. Nesta revisão foram abordadas indicações, vantagens e tipos de biomateriais utilizados para preenchimento do alvéolo dentário imediatamente após a extração dentária sempre que o objetivo for à reabilitação através da instalação de implantes. Mesmo este, biomateriais, apresentando inúmeras qualidades, estudos ainda devem ser feitos a fim de obter a cada dia, um material sintético compatível com o tecido ósseo perdido em quantidades adequadas sem necessitar de cirurgias extra-bucais.

Bone is a specialized vascularized connective tissue that dynamic changes throughout the body. When injured, it has a unique ability to regenerate and repair without the presence of scars, but in some situations due to size of the bone defect does not regenerate completely. Thus, it is necessary to perform guided bone regeneration procedures. For this, the implant dentistry must know the biological bases of alveolar guided bone regeneration and its indications. In this review were addressed indications, advantages and types of biomaterials used for filling the tooth socket immediately after the tooth extraction whenever the goal is rehabilitation through implants installation. Even this, biomaterials, having several qualities, further studies must be done to obtain each day, a synthetic material compatible with the bone tissue lost in proper amounts without the need of extra-oral surgery.

Autotrasplante Digital: Reporte de Caso Clínico / Digital Autotransplantation: Clinical Case Report

El trasplante dentario autólogo se define como el po-sicionamiento de una pieza dentaria autóloga en un alvéolo post extracción o en un lecho formado qui-rúrgicamente. Actualmente, siguiendo los criterios de selección adecuados y una técnica quirúrgica mi-nuciosa, resulta una alternativa terapéutica ideal en ciertos pacientes. La gran variabilidad de implantes dentales y alternativas de injertos óseos han resuelto el problema de sustituir una pieza dentaria perdida. En los pacientes en crecimiento o con potencial de crecimiento residual del proceso alveolar, se pone en evidencia el inconveniente que puede representar la colocación de implantes, lo que hace necesario ree-valuar la conservación de dientes y la utilización de técnicas quirúrgicas clásicas. Las tasas de éxito de los autotrasplantes autólogos han aumentado con el tiempo, alcanzando cifras mayores al 90%. En el pre-sente artículo se reporta un caso clínico de autotras-plante dentario con planificación digital y una réplica tridimensional de la pieza a trasplantar (AU)

Autologous tooth transplantation is defined as the positioning of an autologous tooth in a post-extraction socket or in a surgically formed bed. Currently, following the appropriate selection criteria and a meticulous surgical technique, it is an ideal therapeutic alternative in certain patients. The great variability of dental implants and bone graft alternatives have solved the problem of replacing a lost tooth. In growing patients or with potential for residual growth of the alveolar process, the inconvenience that implant placement can represent is evident, which makes it necessary to reevaluate tooth conservation and the use of classic surgical techniques. The success rates of autologous autologous transplants have increased over time, reaching figures greater than 90%. This article reports a clinical case of dental autotransplantation with digital planning and a three-dimensional replica of the piece to be transplanted (AU)

Cone-beam computed tomographic evaluation of dimensional hard tissue changes following alveolar ridge preservation with leucocyte and platelet-rich fibrin techniques: a pilot study / Avaliação tomográfica computadorizada de feixe cônico das alterações dimensionais de tecido duro após preservação de crista alveolar com técnicas de fibrina rica em leucócitos e plaquetas: um estudo piloto

Objective: This study evaluated the effect of leucocyte and platelet-rich fibrin (L-PRF) techniques used in alveolar ridge preservation on dimensional hard tissue changes of the alveolar ridge assessed using cone-beam computed tomography (CBCT) scans. Material and Methods: Elective alveolar ridge preservation surgeries were performed on seven systemically healthy patients who underwent single posterior tooth extraction. Patients were randomly treated with PRF mixed with a commercial bone xenograft (n = 3) or PRF plug (n = 4). CBCT scans were taken immediately after tooth extraction and then four months later, just before implant surgery. Dimensional alterations in socket height (SH), socket area (SA) and socket volume (SV) were evaluated on CBCT scans by percentage differences before and after treatments. Results: Sockets treated with PRF plus bone xenograft had a tendency to maintain alveolar bone dimensions over time (SH= 11.22% to 82.74%, SA= 1.84% to 48.91% and SV= 9.11% to 203.62%), while sockets treated only with PRF plug technique presented only a modest increase in height (SH= 1.47% to 11.11%) but greater alveolar ridge resorption confirmed by a decrease in socket area and volume dimensions (SA= 0.21% to -24.09% SV= 8.53% to -54.12%). Conclusion: Within the limitations of this study, the maintenance of alveolar socket dimensions was observed when PRF was associated with a xenograft. However, the loss of alveolar ridge dimensions was not entirely prevented by PRF treatment alone.(AU)

Objetivo: Este estudo avaliou o efeito das técnicas de fibrina rica em leucócitos e plaquetas (L-PRF) usadas na preservação da crista alveolar em alterações dimensionais de tecido duro da crista alveolar avaliadas por tomografia computadorizada de feixe cônico (CBCT). Material e Métodos: Foram realizadas cirurgias eletivas de preservação da crista alveolar em sete pacientes sistemicamente saudáveis que foram submetidos a uma única extração dentária posterior. Os doentes foram tratados aleatoriamente com PRF misturado com um xenoenxerto ósseo comercial (n = 3) ou com PRF plug (n = 4). CBCT foi realizada imediatamente após a extração dentária e quatro meses depois, imediatamente antes da cirurgia de implante. Alterações dimensionais na altura do alvéolo (SH), área do alvéolo (SA) e volume do alvéolo (SV) foram avaliadas em exames CBCT por diferenças percentuais antes e depois dos tratamentos. Resultados: Os alvéolos tratados com PRF mais xenoenxerto ósseo apresentaram tendência a manter as dimensões ósseas alveolares ao longo do tempo (SH= 11.22% a 82.74%, SA= 1.84% a 48.91% e SV= 9.11% a 203.62%), enquanto alvéolos tratados apenas com a técnica de PRF plug apresentaram apenas um aumento modesto na altura (SH= 1.47% a 11.11%), mas uma maior reabsorção alveolar confirmada pela redução das dimensões de área e volume do alvéolo (SA= 0.21% a -24.09% SV= 8.53% a -54.12%). Conclusão: Dentro das limitações deste estudo, a manutenção das dimensões alveolares foi observada quando o PRF foi associado ao xenoenxerto. No entanto, a perda das dimensões alveolares não foi totalmente evitada pelo tratamento apenas com PRF. (AU)

Immediate autogenous extracted tooth as a grafting material for fresh socket preservation: a systematic review / Diente autógeno de extracción inmediata como material de injerto para la conservación de alvéolos frescos: una revisión sistemática

Objectives: To evaluate the use of extracted autogenous teeth for socket preservation after tooth extraction. Material and Methods: Cochrane, Scopus, and PubMed databases search was conducted to identify human clinical studies reporting the clinical, radiographic and/or histological outcomes of socket preservation techniques with autogenous extracted tooth Only studies published in English language in the last 10 years were included in the study. Results: In total, 82 articles were identified. Five articles were included in the review. They included 58 teeth that were prepared as a graft for socket preservation. The grafts derived from autogenous teeth were presented in three forms: particles, blocks and powder. The mean bone loss ranged from 0.28 mm to 0.41mm in height and 0.15 mm in width. Conclusion: Immediate autogenous extracted tooth as a grafting material for fresh socket preservation is promising for future daily clinical practice. More clinical comparative studies are needed.

Objetivo: Evaluar el uso de dientes extraídos autógenos para la preservación del alveolo tras la extracción dental.Material y Métodos: Se realizó una búsqueda en las bases de datos Cochrane, Scopus y PubMed para identificar estudios clínicos en humanos que informaban los resultados clínicos, radiográficos y / o histológicos de las técnicas de preservación de alveolos con dientes extraídos autógenos. Solo se incluyeron estudios publicados en inglés en los últimos 10 años. Resultados: En total se identificaron 82 artículos. Se incluyeron cinco artículos en la revisión. Incluyeron 58 dientes que se prepararon como injerto para la preservación del alveolo. Los injertos derivados de dientes autógenos se presentaron en tres formas: partículas, bloques y polvo. La pérdida ósea media osciló entre 0,28 mm y 0,41 mm de altura y 0,15 mm de ancho. Conclusión: El diente autógeno extraído de forma inmediata utilizado como material de injerto para la conservación del alveolo fresco es prometedor para la práctica clínica diaria futura. Se necesitan más estudios clínicos comparativos.

Ensaio clínico controlado, randomizado e cego, para avaliar a preservação alveolar, utilizando biomaterial de colágeno: resultados preliminares / Controlled, randomized and blind clinical trial to evaluate alveolar preservation using collagen biomaterial: preliminary results

Foi proposito desse trabalho analisar a eficiência na manutenção óssea alveolar após extração dentária pelo biomateral xenógeno (Hemospon®) por meio de imagens tomográficas pré e pósoperatórias de 1 mês e 18 meses de acompanhamento. Trata-se de um estudo clínico controlado, randomizado e cego, onde foram realizadas 18 exodontias, e os alvéolos dentários tratados foram selecionados de forma randomizada e divididos em dois grupos. O grupo 1, grupo teste (G1) foi inserido esponja de colágeno xenógena (porco) e o grupo controle (G2), foi mantido apenas o coágulo sanguíneo local. Os alvéolos foram analisados nos sentidos horizontais e verticais e os resultados foram avaliados através dos testes de Wilcoxon e Mann-Whitney, assumindo uma significância estatística de p<0,05. Além das análises tomográficas os pacientes foram acompanhados diariamente na primeira semana para verificar se os tecidos locais apresentavam possíveis complicações, como a presença de infecção, fistulas e dor persistente. Os resultados iniciais (1 mês) constataram que numa análise em conjunto avaliando altura (p<,0,863), comprimento total (p<1,000) e espessura total do alvéolo (p<0,222), não foram observadas diferenças significativas entre os grupos teste e controle, respectivamente. Na análise de 18 meses, observa-se diferença estatística (p < 0,05) em relação a espessura total do alvéolo, porém em relação ao comprimento total do alvéolo e a altura alveolar não foram observados diferenças estatisticamente significativas (p = 0,36; p = 0,674 ­ respectivamente). Quando de compara-se o G1 em momentos diferentes 1 mês e 18 meses em relação as variáveis observa-se diferenças estatísticas significativas no comprimento total do alvéolo e na espessura (p<0,05), porém não houve signicancia em relação à altura do alvéolo (p=0,575). Analisando em separado cada variável em relação aos grupos G1 e G2 não houve diferença estatística numa análise após 18 meses (p = 0,773 ­ altura alveolar e espessura alveolar; p = 1 ­ comprimento total do alvéolo). Durante o acompanhamento clínico em ambos os grupos não houve diferença no padrão do processo de reparo tecidual, sendo possível reabilitação oral dos pacientes. Mediante os dados preliminares apresentados, a pesquisa demonstrou que os alvéolos tratados com esponja de colágeno porcina (Hemospon®) tiveram perdas ósseas menores, principalmente em relação a espessura, podendo-se inferir que há indícios de uma manutenção alveolar com o uso do biomaterial, podendo ser um biomaterial em potencial e de baixo custo para preservação alveolar, sem aumentar os índices de complicações, porém sugere-se uma análise de uma amostra maior para uma melhor análise estatística (AU).

The purpose of this work was to analyze the efficiency of alveolar bone maintenance after tooth extraction by xenogenous biomaterial (Hemospon®) by means of pre and postoperative tomographic images of 1 month and 18 months of follow-up. This is a controlled, randomized, blinded, clinical study, in which 18 extractions were performed, and the treated dental alveolo were randomly select and devided into two groups. Group 1 test group (G1) a xenogen collagen sponge (pig) was inserted and the control grouop (G2), only the local blood clot was maintained. The alveoli were analyzed in the horizontal and vertical directions and the results were evaluated using the Wilcoxon and Mann ­ Whitney tests assumig a statistical significance of p<0,05. In addition to tomographic analyzes, patients were followed up daily in the first week to check whether local tissues had possible complications such as the presence of infection fistulas and persistent pain. The initial results (1 month) found that in a joint analysis evaluanting height (p<0,863) total length (p<1,00) and total thickness of the socket (p<0,222), no significant differences were observed between the test groups and control respectively. When G1 is compared at different times 1 month and 18 months in relation to the variables there are statistically significant differences in the total length of the alveolus and in the thickness (p<0,05) but there was no significance in relation to the height of the alveolus (p = 0,575). Analyzing each variable separately in relation to groups G1 and G2 there was no statistical difference in an analysis after 18 months (p=0,773 ­ alveolar height and alveolar thickness; p = 1 ­ total alveolar length). During clinical follow-up in both groups there was no difference in the pattern of the tissue repair process with patients oral rehabilitation being possible. Through the preliminary data presented the research demonstrated that the alveoli treated with porcine collagen sponge (Hemospon®) had smaller bone losses mainly in relation to thickness and it can be inferred that there are signs of alveolar maintenance with the use of biomaterial it can be a potential and low-cost biomaterial for alveolar preservation without increasing the complication rates however an analysis of a larger sample is suggested for a better statistical analysis (AU).

Biocompatibility and effect on bone formation of a native acellular porcine pericardium: Results of in vitro and in vivo / 北京大学学报(医学版)

OBJECTIVE@#To examine the morphology and biocompatibility of a native acellular porcine pericardium (APP) in vitro and to evaluate its barrier function and effects on osteogenesis when used in guided bone regeneration (GBR) in vivo.@*METHODS@#First, the morphology of APP (BonanGenⓇ) was detected using a scanning electron microscope (SEM). Next, for biocompatibility test, proliferation of human bone marrow mesenchymal stem cells (hBMSCs) were determined using cell counting kit-8 (CCK-8) after being seeded 1, 3 and 7 days. Meanwhile, the cells stained with phalloidine and 4, 6-diamidino-2-phenylindole (DAPI) were observed using a confocal laser scanning microscopy (CLSM) to view the morphology of cell adhesion and pattern of cell proliferation on day 5. A 3-Beagle dog model with 18 teeth extraction sockets was used for the further research in vivo. These sites were randomly treated by 3 patterns below: filled with Bio-OssⓇand coverd by APP membrane (APP group), filled with Bio-OssⓇand covered by Bio-GideⓇmembrane (BG group) and natural healing (blank group). Micro-CT and hematoxylin-eosin (HE) were performed after 4 and 12 weeks.@*RESULTS@#A bilayer and three-dimensional porous ultrastructure was identified for APP through SEM. In vitro, APP facilitated proliferation and adhesion of hBMSCs, especially after 7 days (P < 0.05). In vivo, for the analysis of the whole socket healing, no distinct difference of new bone ratio was found between all the three groups after 4 weeks (P>0.05), however significantly more new bone regeneration was detected in APP group and BG group in comparison to blank group after 12 weeks (P < 0.05). The radio of bone formation below the membrane was significantly higher in APP group and BG group than blank group after 4 and 12 weeks (P < 0.05), however, the difference between APP group and BG group was merely significant in 12 weeks (P < 0.05). Besides, less resorption of buccal crest after 4 weeks and 12 weeks was observed in APP group of a significant difference compared in blank group (P < 0.05). The resorption in BG group was slightly lower than blank group (P>0.05).@*CONCLUSION@#APP showed considerable biocompatibility and three-dimentional structure. Performing well as a barrier membrane in the dog alveolar ridge preservation model, APP significantly promoted bone regeneration below it and reduced buccal crest resorption. On the basis of this study, APP is a potential osteoconductive and osteoinductive biomaterial.

Efficacy of two barrier membranes and deproteinized bovine bone mineral on bone regeneration in extraction sockets: A microcomputed tomographic study in dogs / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effect of two barrier membranes [multilaminated small intestinal submucosa (mSIS) and bioresorable collagen membrane (Bio-Gide)] combined with deproteinized bovine bone mineral Bio-Oss on guided bone regeneration through a canine extraction sockets model.@*METHODS@#The distal roots of 18 premolars of the Beagle' s bilateral maxillary and mandibular were removed, and 18 extraction sockets were obtained. They were randomly divided into 3 groups, and the following procedures were performed on the sockets: (1) filled with Bio-Oss and covered by mSIS (mSIS group), (2) filled with Bio-Oss and covered by Bio-Gide (BG group), (3) natural healing (blank control group). Micro-computed tomograph (Micro-CT) was performed 4 and 12 weeks after surgery to eva-luate the new bone regeneration in the sockets of each group.@*RESULTS@#The postoperative healing was uneventful in all the animals, and no complications were observed through the whole study period. Micro-CT analysis showed that the new bone fraction in the mSIS group and the BG group was significantly higher than that in the blank control group at the end of 4 weeks and 12 weeks (P < 0.05), and more new bone fraction was observed in the mSIS group than in the BG group, but the difference was not statistically significant (P>0.05). The new bone fraction of coronal third part of the socket in the mSIS group and BG group at the end of 4 weeks were significantly higher than that of the middle and apical third part of each group (P < 0.05). The values of bone mineral density were similar at 4 weeks in all the groups (P>0.05), but were significantly higher than that in the control group at the end of 12 weeks (P < 0.05). The bone morphometric analysis showed that the trabecular number and trabecular spacing were significantly better in the mSIS group and the BG group than in the control group at the end of 4 weeks and 12 weeks (P < 0.05), while the value in the mSIS group was slightly higher than in the BG group, but the difference was not statistically significant (P>0.05). The difference in trabecular thickness between all the groups was not statistically significant (P>0.05).@*CONCLUSION@#mSIS membrane as a barrier membrane combined with deproteinized bovine bone mineral can enhance new bone formation in canine extraction sockets, similar to Bio-Gide collagen membrane.

In situ endoscopic analysis of bone microstructure and vascularization in post-extraction sites immediately after a minimally invasive vertical tooth extraction in teeth with different periodontal status / Análisis endoscópico in situ de la microestructura ósea y vascularización en alvéolos post-extracción inmediatamente después de una extracción dental mínimamente invasiva en dientes con diferente estado periodontal

SUMMARY: The aim of this study was to perform an in situ endoscopic analysis of the vascularization of post-extraction sites immediately after a non-traumatic extraction in terms of the number of blood vessels per field (NBV), relative area of blood vessels (RABV) and relative area of unmineralized bone (RAUB) in teeth with different periodontal status (PS). This assessment was performed using short distance support immersion endoscopy (SD-SIE). Ten patients (4 men/ 6 women, aged between 25 and 44) were selected. From them, 10 teeth were extracted due to periodontal reasons or other motives. These teeth were then categorized into 2 groups according to their PS, either as periodontally compromised (PC) (clinical attachment loss (CAL) > 7 mm and probing depth (PD) > 5 mm) or periodontally healthy (PH) (CAL < 7 mm and PD < 5 mm, without bleeding or suppuration during periodontal probing), and mobile (M) (> 1 mm horizontally) or immobile (I) (< 1 mm horizontally). The minimally invasive vertical tooth extractions were performed using the Benex ® extractor. Immediately after extraction, a rigid immersion endoscope with a diameter of 2.7 mm was introduced, and a video-alveoloscopy was carried out. This video was analyzed by ImageJ software for the quantification of NBV, RABV and RAUB per field of the post-extraction sites with different PS (PC, PH, M, I) were quantified. In the PC group, significantly greater values for RAUB were observed (33.45 %) compared to those from the PH group (19.65 %). Compared with the M group, the I group did not show significant differences in terms of RAUB or RABV. There were also no differences in NBV in both groups (Means: 33.8 vs. 30.5, respectively).

RESUMEN: El objetivo de este estudio fue realizar un análisis endoscópico in situ de la vascularización de los alvéolos post-extracción inmediatamente después de una extracción atraumática en términos de número de vasos sanguíneos por campo de observación (NBV), área relativa de vasos sanguíneos (RABV) y el área relativa de espacios no mineralizados (RAUB) en dientes con diferente estado periodontal (PS). Esta evaluación se realizó mediante endoscopía de inmersión de corta distancia (SD-SIE). Se seleccionaron diez pacientes (4 hombres / 6 mujeres, con edades comprendidas entre 25 y 44). De ellos, se extrajeron 10 dientes debido a razones periodontales u otros motivos. Estos dientes se clasificaron en 2 grupos según su PS, ya sea como periodontalmente comprometidos (PC), los que presentaban un nivel de inserción clínica (CAL) ≥ 7 mm y una profundidad de sondaje (PD) ≥ 5 mm; o periodontalmente sanos (PH) (CAL <7 mm y PD <5 mm, sin sangramiento o supuración durante el sondaje periodontal). También se categorizaron según su movilidad como móvil (M) (≥ 1 mm horizontalmente) o inmóvil (I) (<1 mm horizontalmente). Las extracciones verticales mínimamente invasivas se realizaron con el extractor Benex ®. Inmediatamente después de la extracción, se introdujo un endoscopio rígido de inmersión con un diámetro de 2.7 mm, con el cual se realizó una video-alveoloscopía. Este video fue analizado por el software ImageJ para la cuantificación de NBV, RABV y RAUB por campo, de los alvéolos post-extracción con diferente estado periodontal. En el grupo de dientes PC, se observaron valores significativamente mayores para RAUB (33.45%) en comparación con los del grupo PH (19.65 %). En comparación con el grupo M, el grupo I no mostró diferencias significativas en términos de RAUB o RABV. Tampoco hubo diferencias en el NBV en ambos grupos (Media: 33.8 frente a 30.5, respectivamente).

Systemic lithium chloride administration improves tooth extraction wound healing in estrogen-deficient rats

Abstract The purpose of this investigation was to evaluate the effects of lithium chloride (LiCl) on the socket healing of estrogen-deficient rats. Seventy-two rats were allocated into one of the following groups: Control, Ovariectomy and LiCl (150 mg/kg/2 every other day orally) + Ovariectomy. Animals received LiCl or water from the 14th day post-ovariectomy, until the completion of the experiment. On the 21st day after ovariectomy, the first molars were extracted. Rats were euthanized on the 10th, 20th and 30th days following extractions. Bone healing (BH), TRAP positive cells and immunohistochemical staining for OPG, RANKL, BSP, OPN and OCN were evaluated. The Ovariectomy group presented decreased BH compared to the LiCl group at 10 days, and the lowest BH at 20 days (p<0.05). At 30 days, the Ovariectomy and LiCl-groups presented lower BH than that of the Control (p<0.05). The number of TRAP-stained cells was the lowest in the LiCl group at 20 days and the highest in the Ovariectomy group at 30 days (p<0.05). At 10 days of healing, the LiCl group demonstrated stronger staining for all bone markers when compared to the other groups, while the Ovariectomy group presented higher RANKL expression than that of the Control (p<0.05). LiCl enhanced bone healing in rats with estrogen deficiency, particularly in the initial healing phases. However, as data on the effects of lithium chloride on bone tissue are still preliminary, more studies related to its toxicity and protocol of administration are necessary before its application in clinical practice.

Resumo O objetivo deste estudo foi avaliar os efeitos do Cloreto de Lítio (ClLi) na cicatrização de alvéolos de ratas deficientes em estrogênio. Setenta e duas ratas foram alocadas em um dos seguintes grupos: Controle, Ovariectomia e Cloreto de Lítio (150mg/kg/ oralmente a cada 2 dias) + ovarectomia. Os animais receberam ClLi ou água a partir do 14º dia pós-ovariectomia, até a conclusão do experimento. No 21º dia após a ovariectomia, os primeiros molares foram extraídos. As ratas foram sacrificadas nos dias 10, 20 e 30 após extrações. Foram avaliadas a cicatrização óssea (BH), células positivas para TRAP e coloração imuno-histoquímica para OPG, RANKL, BSP, OPN e OCN. O grupo Ovariectomia apresentou BH diminuída em comparação ao grupo LiCl aos 10 dias e a menor BH aos 20 dias (p<0,05). Aos 30 dias, os grupos Ovariectomia e LiCl apresentaram menor BH do que o Controle (p<0,05). O número de células positivas para TRAP foi menor no grupo ClLi em 20 dias e o maior no grupo Ovariectomia em 30 dias (p<0,05). Aos 10 dias de cicatrização, o grupo ClLi demonstrou imunomarcação mais intensa em todos os marcadores testados quando comparado aos outros grupos, enquanto o grupo Ovariectomia apresentou maior expressão de RANKL do que a do controle (p<0,05). O ClLi melhorou a cicatrização óssea em ratos com deficiência de estrogênio, particularmente nas fases iniciais do reparo. No entanto, como os dados sobre os efeitos do cloreto de lítio no tecido ósseo ainda são preliminares, mais estudos relacionados à sua toxicidade e protocolo de administração são necessários antes de sua aplicação na prática clínica.

Prosthetically driven alveolar reconstructions: a retrospective study

Abstract This study aims to evaluate the post-extraction alveolar bone reconstruction amongst 12 patients exhibiting loss of buccal bone plate in a tooth of the anterior region of the maxilla using the prosthetically-driven alveolar reconstruction technique (PDAR). In PDAR, a partial fixed provisional prosthesis (PFPP [conventional or adhesive]) with a specially designed pontic maintains the clot in a mechanically stable position during alveolar regeneration. Moreover, the pontic design, in hourglass shape and located in the subgingival area, also prevents gingival margins from collapsing. Gingival recession was evaluated through the 6-month healing period. Cone beam computed tomography (CBCT) was performed 1 month before and 8 months after PDAR treatment. For the primary outcome, in the panoramic imaging, the central area of bone defect in each tooth was selected for linear measurements. Measurements of the vertical buccal bone gain and the gain in thickness in the alveolar bone crest were obtained 8 months after PDAR. Descriptive statistics and intraclass correlation coefficient analysis were conducted. After treatment, all patients showed bone formation (a mean vertical gain of 7.1±3.7 mm, associated with a horizontal mean gain of 4.5±1.4 mm in the alveolar bone crest). The intraclass correlation coefficient for the measurements performed using CBCT was 0.999. No gingival recession, greater than 1 mm, was observed. Lower-morbidity procedures without the use of biomaterials may be a useful in post-extraction alveolar ridge regeneration and/or preservation. PDAR promoted alveolar bone formation without flaps, grafts and membranes.

Resumo Este estudo teve como objetivo avaliar a reconstrução do osso alveolar após extração em 12 pacientes com perda da tábua óssea vestibular em dentes na região anterior da maxila usando a técnica da reconstrução alveolar proteticamente guiada (RAPG). Na RAPG, uma prótese parcial fixa provisória (PPFP [convencional ou adesiva]) com um pôntico com design específico mantém o coágulo numa posição mecanicamente estável. Além disso, o design do pôntico, com formato de ampulheta e localizado na área subgengival, também previne o colapso das margens gengivais. A recessão gengival foi avaliada durante o período de cicatrização de 6 meses. Tomografias computadorizadas cone beam (TCCB) foram feitas 1 mês antes e 8 meses após o tratamento com a RAPG. Para o desfecho primário, nas imagens panorâmicas, a área central do defeito ósseo em cada dente foi selecionada para as medições lineares. As medições do ganho vertical ósseo vestibular e do ganho em espessura na crista óssea alveolar foram realizadas. A análise estística descritiva e a análise do coeficiente de correlação intraclasse forma realizados. Após o tratamento, todos os pacientes apresentaram formação óssea (ganho vertical médio de 7,1±3,7 mm, associado a ganho horizontal médio de 4,5±1,4 mm na crista óssea alveolar). O coeficiente de correlação intraclasse foi de 0,999. Nenhuma retração gengival acima de 1 mm foi observada. Procedimentos com baixa morbidade sem o uso de biomateriais podem ser úteis na regeneração/preservação do rebordo após as extrações. A RAPG promove a formação do osso alveolar sem o uso de retalhos, enxertos e membranas.

Manejo bucomaxilofacial de tecidos moles e duros após queda de bicicleta: relato de caso / Bucomaxilofacial management handling of moles and hard tissues after bicycle fall: case report

Introdução: A face é a região do corpo humano mais projetada o qual propicia a lesões traumáticas com importantes sequelas. Esta, desempenha funções estéticas e funcionais como as expressões faciais. As reconstruções dos tecidos devem ser realizadas com a finalidade de restabelecer a funcionalidade, assimetria e o contorno da região. Devese dar importância as características dos tecidos moles lesionados, o qual deve ser reconstituído com a aparência mais próxima ao local da lesão. O presente trabalho tem como objetivo relatar a reconstrução do lábio superior e do alvéolo-dentário imediatamente após um acidente ciclístico. Relato de caso: Paciente do sexo masculino, 26 anos de idade, normossistêmico, compareceu ao serviço de emergência de Cirurgia e Traumatologia Buco-Maxilo-Facial devido a uma queda de bicicleta, a qual teria sido ocasionada pela quebra do garfo, o qual evoluiu com laceração em lábio superior e fratura dentro-alveolar. Foi realizado a reconstrução do lábio superior e alvéolos dentários. O paciente evoluiu 45 dias do pós-operatório com discreta cicatriz e função preservada. Considerações finais: Os traumas por bicicleta podem ter graves consequências orofaciais. Constata-se a indispensável avaliação profissional quanto as características dos tecidos moles e dento-alveolares, possibilitando ao paciente o retorno estético e funcional... (AU)

Introduction: The face is the region of the most projected human body which leads to traumatic injuries with important sequelae. It performs aesthetic and functional functions such as facial expressions. Tissue reconstructions should be performed with the purpose of restoring the functionality, asymmetry and contour of the region. The characteristics of lesioned soft tissues should be considered, which should be reconstituted with the appearance closest to the lesion site. The aim of the present study is to report the reconstruction of the upper lip and the dental alveolus immediately after a cycling accident. Case report: Male patient, 26 years of age, normossemic, attended the emergency service of Buco-Maxillo-Facial Surgery and Traumatology due to a bicycle fall, which would have been caused by the fork breaking, which evolved with laceration in the lip superiority and in-alveolar fracture. A reconstruction of the upper lip and dental alveoli was performed. The patient evolved 45 days postoperatively with discrete scar and preserved function. Final considerations: Bicycle traumas can have serious orofacial consequences. It is necessary to evaluate the professional characteristics of the soft and dentoalveolar tissues, allowing the patient to return aesthetic and functional... (AU)

Odontectomia parcial intecional: relato de caso clínico / Intentional partial odontectomy: a case report

Introdução: A Odontectomia Parcial Intencional ou Coronectomia é uma abordagem cirúrgica que consiste na remoção da porção coronária de molares mandibulares impactados e a manutenção das suas raízes no alvéolo dentário. Esta técnica é indicada quando há íntima relação entre o dente e o canal mandibular e tem por principal objetivo evitar lesões ao nervo alveolar inferior. Relato de Caso: Paciente do sexo masculino, 24 anos, ASA I, compareceu a Clínica Escola de Cirurgia de uma universidade pública para exodontia de terceiro molar inferior impactado (48). Ao exame clínico o dente apresentava-se semi-incluso e ao exame radiográfico (panorâmica e tomografia computadorizada), observou-se íntima relação da raiz do dente com o canal mandibular. Diante disto, foi realizada Odontectomia Parcial Intencional, com o intuito de preservação de feixe vásculo-nervoso adjacente. Paciente evoluiu satisfatoriamente sem sinais de infecção ou alteração sensorial de nervo alveolar inferior. Considerações finais: A Odontectomia Parcial Intencional é uma técnica segura, eficaz e de previsibilidade significativa, sendo uma alternativa que pode ser empregada em exodontias de molares mandibulares inclusos próximos ao canal mandibular, minimizando os riscos de lesões nervosas para os pacientes... (AU)

Introduction: Intentional partial odontectomy or coronectomy is a surgical approach that consists of removing the coronary portion of impacted mandibular molars and maintaining their roots in the dental alveolus. This technique is indicated when there is an intimate relationship between the tooth and the mandibular canal and its main objective is prevent injuries to the lower alveolar nerve. Case Report: Male patient, 24 years old, ASA I, compared the Clinical School of Surgery of a public university for extraction of the impacted lower third molar (48). On clinical or dental examination, we present semi impacted wisdom tooth and on radiographic examination (panoramic + computed tomography), an intimate relationship between the root of the tooth and the mandibular canal was observed. Therefore, intentional partial odontectomy was performed in order to preserve the adjacent vascular-nervous bundle. The patient progressed satisfactorily without signs of infection or sensory alteration of lower alveolar nerve. Final considerations: Intentional partial odontectomy is a safe, effective and predictable technique, being an alternative that can be used in extractions of mandibular molars, including those close to the mandibular canal, minimizing the risk of nerve injuries to patients... (AU)

Preservação Tecidual Peri-Implantar em Implante Imediato Posterior com Cicatrizador Personalizado: Relato de Caso / PERI-IMPLANT TISSUE PRESERVATION IN IMMEDIATE POSTERIOR IMPLANT PLACEMENT WITH CUSTOMIZED HEALING ABUTMENT: CLINICAL CASE REPORT

The maintenance of natural dentition under optimal function, health and aesthetics conditions is the main objective of dental treatments, but when therapeutic possibilities are exhausted, dental extractions become necessary. Bone remodeling due to post-extraction alveolar healing may result in volume changes in the region. This topic is common in renowned dentistry scientific publications and several researchers recommend tissue regenerative procedures and seek solutions minimize volume reduction. Among these procedures, the immediate installation of implants in post- extraction sockets without flap elevation is an alternative that guarantees functional and aesthetic benefits in the final result of the rehabilitation. This paper presents a clinical case that shows a practical and viable alternative therapy for adequate alveolar healing. In this clinical case, the use of immediate implants and personalized healing abutments with flowable resin composite reduced alveolar healing remodeling and allowed the preservation of the gingival architecture and to obtain an ideal emergency profile for performing the permanent prosthesis supported by implant.

Consideraciones para el manejo de un implante inmediato en alvéolos infectados: una actualización / Considerations for the management of an immediate implant in infected sockets: an update

Introducción: La instalación inmediata del implante posterior a la extracción dental se está convirtiendo en un procedimiento de rutina debido a la reducción del tiempo de tratamiento y a la preservación de las estructuras anatómicas remanentes. Sin embargo, en muchos casos esta técnica involucra dientes afectados con procesos infecciosos. Hasta ahora, no se ha descrito a ciencia cierta el grado de éxito o fracaso del implante inmediato en alvéolos infectados, ni se ha establecido un protocolo para el manejo de este tipo de casos. Objetivo: Realizar una revisión bibliográfica actualizada, para determinar qué consideraciones se deben tener para instalar un implante inmediato en alvéolos con procesos infecciosos. Conclusión: Es posible obtener las ventajas de la instalación inmediata del implante en alvéolos infectados mediante la aplicación de un adecuado manejo clínico, donde se considere un adecuado tratamiento antibiótico, acompañado de un correcto curetaje alveolar, respetar la cadena de asepsia y antisepsia, posición subcrestal del implante y obtener siempre una buena estabilidad primaria del implante (AU)

Introduction: The immediate placement of the implant after dental extraction is a procedure that every time is becoming a routine procedure due to the reduction of the treatment time and the preservation of the remaining anatomical structures. However, in many cases, this technique involves affected teeth with infectious processes. Until now, the degree of success or failure of the immediate implant in infected alveoli has not been described for sure; nor has a protocol been established for the management of these types of cases. Objective: Carry out an updated bibliographic review, to determine what considerations must be taken to install an immediate implant in alveoli with infectious processes. Conclusion: Is possible obtain the advantages of the immediate installation of the implant in infected alveoli through the application of adequate clinical management, where appropriate antibiotic treatment is considered, accompanied by proper alveolar curettage, respect the aseptic and antiseptic chain, implant subcrestal position and always obtain a good primary stability of the implant (AU)

Efecto del ultrasonido de baja intensidad (USBI) sobre el movimiento dentario ortodóncico: estudio in vivo en ratas Sprague-Dawley / Effect of low intensity ultrasound (USBI) in the orthodontic dental movement: in vivo study in Sprague-Dawley rats

Este estudio se realizó con el propósito de analizar el efecto de la aplicación de ondas de USBI sobre la velocidad y distancia de movimiento dentario, y su efecto a nivel histológico en ratas Sprague-Dawley. Veintitrés ratas macho Sprague-Dawley fueron parte del experimento, las que fueron divididas aleatoriamente en tres grupos. Cinco ratas fueron utilizadas como control sin movimiento dentario ortodóncico (MDO), nueve ratas fueron sometidas a una aplicación de fuerza ortodóncica sin aplicación de USBI y nueve fueron sometidas a una aplicación de fuerza ortodóncica con USBI. Estas fuerzas ortodóncicas fueron realizadas entre el aspecto mesio vestibular del primer molar superior izquierdo y el incisivo central superior, traccionando el molar hacia mesial, aplicando una fuerza aproximada de 50 gramos durante 21 días, debido a problemas con la sedación estos dos últimos grupos quedaron compuestos de seis y ocho ratas respectivamente. En el grupo MDO sin USBI, se registró una reducción del espacio entre molares e incisivos de 2 mm. En el grupo MDO con USBI dicha reducción fue de 3.4 mm, siendo esta diferencia estadísticamente significativa. Histológicamente el grupo MDO c/USBI mostró un perímetro vascular y espacios medulares aumentados respecto de los otros grupos, no obstante, no se encontraron diferencias significativas en la cantidad de osteoclastos. Fue posible observar y demostrar cuantitativamente que el USBI es una forma de estimulación mecánica eficiente para la aceleración del MDO sobre un período experimental de 21 días, donde se observaron diferencias significativas entre el grupo control, el grupo MDO sin USBI y el grupo MDO con USBI en la magnitud del movimiento dentario. Se observó una mayor vascularidad en el grupo con USBI, expresando perímetros vasculares de mayor tamaño, esto pudo deberse al efecto estimulatorio del ultrasonido sobre la angiogénesis.

The objective of this study was to analyze the effect of USBI wave application on the speed and distance of dental movement, and its effect at histological level in SpragueDawley rats. In this study twenty-three male Sprague-Dawley rats were randomly divided into three groups. Five rats were used as control without orthodontic tooth movement (MDO), nine rats were subjected to an orthodontic force application without USBI application, and nine were subjected to an orthodontic force application with USBI. The orthodontic forces were performed between the vestibular mesio aspect of the first upper left molar and upper central incisor, pulling the molar mesially, applying an approximate force of 50 grams for 21 days. In light of sedation problems these last two groups were composed of six and eight rats respectively. In the MDO group without USBI, there was a reduction in the space between molars and incisors of 2 mm. In the MDO group with USBI this reduction was 3.4mm, this difference being statistically significant. Histologically, the MDO c / USBI group showed a vascular perimeter and enlarged spinal spaces with respect to the other groups, however, no significant differences were found in the amount of osteoclasts. It was possible to quantitatively demonstrate that USBI is a form of efficient mechanical stimulation for MDO acceleration over an experimental 21-day period, where significant differences were observed in tooth movement between the control group, the group without USBI and the group with USBI. A greater vascularity was observed in the group with USBI, expressing larger vascular perimeters, which could be due to the stimulatory effect of ultrasound on angiogenesis.

The effects of intro-oral parathyroid hormone on the healing of tooth extraction socket: an experimental study on hyperglycemic rats

Abstract Objective To investigate the effects of intro-oral injection of parathyroid hormone (PTH) on tooth extraction wound healing in hyperglycemic rats. Methodology 60 male Sprague-Dawley rats were randomly divided into the normal group (n=30) and DM group (n=30). Type 1 diabetes mellitus (DM) was induced by streptozotocin. After extracting the left first molar of all rats, each group was further divided into 3 subgroups (n=10 per subgroup), receiving the administration of intermittent PTH, continuous PTH and saline (control), respectively. The intermittent-PTH group received intra-oral injection of PTH three times per week for two weeks. A thermosensitive controlled-release hydrogel was synthesized for continuous-PTH administration. The serum chemistry was determined to evaluate the systemic condition. All animals were sacrificed after 14 days. Micro-computed tomography (Micro-CT) and histological analyses were used to evaluate the healing of extraction sockets. Results The level of serum glucose in the DM groups was significantly higher than that in the non-DM groups (p<0.05); the level of serum calcium was similar in all groups (p>0.05). Micro-CT analysis showed that the DM group had a significantly lower alveolar bone trabecular number (Tb.N) and higher trabecular separation (Tb.Sp) than the normal group (p<0.05). The histological analyses showed that no significant difference in the amount of new bone (hard tissue) formation was found between the PTH and non-PTH groups (p>0.05). Conclusions Bone formation in the extraction socket of the type 1 diabetic rats was reduced. PTH did not improve the healing of hard and soft tissues. The different PTH administration regimes (continuous vs. intermittent) had similar effect on tissue healing. These results demonstrated that the metabolic characteristics of the hyperglycemic rats produced a condition that was unable to respond to PTH treatment.

Avaliação da alteração óssea dimensional pós-exodontia e planejamento virtual 3D em dentes anteriores superiores através da técnica de tomografia computadorizada de feixe cônico (TCFC) / Evaluation of alveolar ridge dimensional changes after tooth extraction and 3D virtual planning in anterior maxilla by cone beam computerized tomography (CBCT) technique

A perda dental na região anterior da maxila resulta em alterações dimensionais ósseas, que podem estar associadas a gênero, idade e certos tipos dentários. Em alguns casos, procedimentos de aumento alveolar prévios à instalação de implantes podem ser necessários. O planejamento virtual 3D pode ajudar o clínico nessa tomada de decisão, assim como na seleção do diâmetro dos implantes. Utilizando a técnica de TCFC a proposta deste estudo foi: a) avaliar lados dentado e edêntulo quanto a dimensões alveolares e de rebordo; b) verificar dentre os alvéolos pós-extração a porcentagem de casos que permitiram a instalação virtual de implantes de diâmetro convencional e diâmetro reduzido, assim como casos em que não foi possível a instalação de implante sem reconstrução de rebordo alveolar prévio; c) avaliar fatores associados com os itens anteriores; d) verificar a frequência e localização de fenestrações e deiscências ósseas após a instalação virtual dos implantes, assim como os fatores associados com a presença desses defeitos. As imagens de TCFC foram adquiridas por tomógrafo iCAT e as mensurações, assim como o planejamento virtual 3D, foram realizados com o programa Xelis Dental®. Os lados dentado e edêntulo foram comparados em relação à área, altura e largura. Todas as mensurações foram realizadas em intervalos de 3 mm de apical à coronal, iniciando a partir do plano palatino. O planejamento virtual de implantes foi realizado apenas em rebordos alveolares com 4,0 mm ou mais de largura no topo do rebordo. A seleção do diâmetro do implante (convencional ou reduzido) baseou-se no posicionamento virtual do implante a 1 mm apicalmente ao topo do rebordo. Dentre 2.574 TCFC analisadas, 81 imagens apresentaram ausência de incisivos centrais, incisivos laterais e caninos e seus dentes contralaterais correspondentes. Diferenças significantes foram observadas entre os lados dentado e edêntulo em relação à área total e largura a 6, 9, 12, 15, 18 mm e crista-crista, quando a média total e diferentes tipos dentários foram considerados (p<0,05). Foi observado que caninos apresentaram a maior porcentagem de redução em largura do rebordo alveolar. Houve diferença significativa entre homens e mulheres em relação às variáveis (p<0,05). No planejamento virtual 3D, 39 casos necessitaram de reconstrução de rebordo alveolar prévio, 23 permitiram a instalação de implantes de diâmetro reduzido apenas e 19 permitiram a instalação de implantes de diâmetro convencional. Apenas 8% de incisivos laterais permitiram a instalação de implantes de diâmetro convencional comparado a 30,4% de incisivos centrais e caninos (p=0,02). Para os incisivos laterais, 44% permitiram a instalação de implantes de diâmetro reduzido comparado a 21,4% de incisivos centrais e caninos (p=0,03). Dentre os 43 rebordos alveolares que permitiram o planejamento virtual de implantes, foram observadas deiscências ou fenestrações na instalação de 25 (58,1%) implantes de diâmetro reduzido e 34 (79,1%) implantes de diâmetro convencional. Concluiu-se que houve uma significativa redução em área e largura do processo alveolar após a extração dentária, especialmente em caninos. Além disso, houve uma associação entre tipo dentário e planejamento virtual 3D.