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Authors
Abstract(s)
Introdução:
Após a extração dentária tem início o processo de remodelação dos tecidos ósseos e tecidos moles, provocando alterações morfológicas nos mesmos. A colocação de implantes dentários imediatos com a aplicação de substitutos ósseos e matrizes de colagénio reabsorvíveis tende a minimizar a reabsorção que tem lugar nos tecidos peri-implantares. Apesar desta vantagem, é difícil prever com precisão o que acontece após esta sequência de tratamento, uma vez que são envolvidos tanto tecidos ósseos como tecidos moles da região peri-implantar.
Objetivos:
Analisar as alterações volumétricas que ocorrem nos tecidos ósseos e tecidos moles peri-implantares, assim como verificar quais as características ósseas iniciais que desempenham um papel preponderante nas alterações que os tecidos peri-implantares sofrem após a colocação de implantes imediatos na zona estética maxilar durante o primeiro ano de tratamento.
Materiais e Métodos:
Vinte e seis pacientes tratados com implantes dentários unitários após extração dentária foram incluídos neste estudo. Uma tomografia computorizada por feixe cónico (CBCT) efetuada previamente à extração dentária confirmou a integridade da cortical óssea vestibular. O espaço existente entre o implante e a parede óssea alveolar vestibular foi medido para futura análise (BID) e posteriormente preenchido por um substituto ósseo. Impressões digitais foram efetuadas antes da extração dentária (T0) e a um (T1), quatro (T2) e doze meses (T3) após colocação do implante dentário. Os ficheiros de estereolitografia (STL) obtidos foram sobrepostos através de um programa informático, permitindo realizar uma análise volumétrica tridimensional dos tecidos peri-implantares, calculando diferentes variáveis como a espessura, área e volume, que expressaram as alterações entre T0 e os seguintes controlos pós-operatórios. A análise da imagem de CBCT permitiu obter diferentes parâmetros pré (T0) e pós-operatórios (T3) como a espessura da cortical alveolar vestibular (BT), a altura da cortical vestibular (BH), a altura da cortical palatina (PH) e a distância entre as mesmas (BPD).
Resultados:
Através da análise linear observou-se uma variação total de espessura em T1, T2 e T3 de -0,45±0,51mm, -0,46±0,39 e -0,52±0,38, respetivamente. A variação volumétrica da face vestibular em T1, T2 e T3 foi de -7,20±6,62%, -7,82±6,86% e -9,52±7,44%, respetivamente. Verificou-se também uma alteração do parâmetro BPD em T3 de -1,50±1,09mm e, após um ano de observação, indivíduos com BT ≤1mm exibiram maior variação de espessura vestibular (-0,48±0,28mm), comparativamente aos pacientes com BT>1mm (-0,17± 0,11mm) (p=0,049). Uma regressão linear múltipla determinou os parâmetros BT e BPDT0 como determinantes na evolução das variáveis de espessura e volume ao fim de quatro meses, não sendo encontrada significância estatística no que concerne à influência de BID. Uma correlação linear positiva foi observada entre as variações de BPD (T0-T3) e as alterações totais de espessura e volume verificadas em T1, T2 e T3.
Conclusão:
A colocação de implantes imediatos após a extração dentária é um tratamento previsível com uma taxa de sucesso comparável ás técnicas convencionais de colocação de implantes em zonas alveolares cicatrizadas, apesar de não impedir na totalidade o processo reabsortivo do osso alveolar associado à extração do dente.
A espessura da cortical vestibular influencia significativamente as alterações de espessura e volume que ocorrem nos tecidos peri-implantares em tratamentos com implantes imediatos pós-extracionais do sector anterior maxilar.
Introduction: After a single-tooth extraction, remodelling processes are initiated and morphological changes occur in the alveolar bone. Immediate implant placement associated with the use of bone substitutes and a collagen matrix seems to reduce the amount of resorption at peri-implant areas. Despite the advantages with the use of these techniques, it is difficult to predict with precision what is going to happen after immediate implant placement, since it involves hard and soft tissue volume changes. Aim: To evaluate the volumetric changes in hard and soft peri-implant tissues after flapless immediate implant placement in the aesthetic zone during the first year of treatment as well as determinate which initial alveolar bone features may play a crucial role on peri-implant tissues alterations. Materials and Methods: Twenty-six patients treated with single-tooth maxillary implants after flapless tooth extraction between 15 to 25, were included in this study. The horizontal implant/bone gap was measured for further analysis (BID) and filled with a xenograft bone substitute. Digital impressions were taken prior to extractions (T0), one month (T1), four months (T2) and 12 months (T3) after implant insertion. The obtained Standard Tessellation Language (STL) files were superimposed with a computer software allowing to create a colour map that quantitatively analysed the three-dimensional variations occurred in the intervened areas and adjacent tissues. Variables related to thickness, area and volume representing the changes between T0 and the different postoperative follow-ups were computed. A CBCT exam allowed to access pre (T0) and postoperative (T3) parameters such as buccal bone thickness (BT), buccal plate height (BH), palatal plate height (PH) and the distance between them (BPD). XIV Results: The linear measurements showed a total mean change in thickness at T1, T2 and T3 of -0,45±0,51mm, -0,46±0,39 and -0,52±0,38, respectively. Buccal volume variation at T1, T2 and T3 was -7,20±6,62%, -7,82±6,86% and -9,52±7,44%, respectively. A mean variation on BPD of -1,50±1,09mm was observed at T3 and after 1-year of treatment subjects with BT≤1mm exhibited a significantly increased buccal thickness variation (-0,48±0,28mm) than patients with BT>1mm (-0.17± 0,11mm) (p=0,049). A multi-variate regression analysis proved a statistical significant influence of BT and BPDT0 on thickness and volume variations after 4 months, whereas no statistical significance was found on BID effect. A positive linear correlation was detected between BPD variations (T0-T3) and total thickness and volume alterations at T1, T2 and T3. Conclusion: After the first year of treatment following flapless single immediate implant placement in maxilla, peri-implant tissues showed a continuous alterations resulting in a thickness change that occurred mainly in the first month and tended to be stable after the fourth month. Thickness and volume variations were significantly influenced by initial buccal bone thickness.
Introduction: After a single-tooth extraction, remodelling processes are initiated and morphological changes occur in the alveolar bone. Immediate implant placement associated with the use of bone substitutes and a collagen matrix seems to reduce the amount of resorption at peri-implant areas. Despite the advantages with the use of these techniques, it is difficult to predict with precision what is going to happen after immediate implant placement, since it involves hard and soft tissue volume changes. Aim: To evaluate the volumetric changes in hard and soft peri-implant tissues after flapless immediate implant placement in the aesthetic zone during the first year of treatment as well as determinate which initial alveolar bone features may play a crucial role on peri-implant tissues alterations. Materials and Methods: Twenty-six patients treated with single-tooth maxillary implants after flapless tooth extraction between 15 to 25, were included in this study. The horizontal implant/bone gap was measured for further analysis (BID) and filled with a xenograft bone substitute. Digital impressions were taken prior to extractions (T0), one month (T1), four months (T2) and 12 months (T3) after implant insertion. The obtained Standard Tessellation Language (STL) files were superimposed with a computer software allowing to create a colour map that quantitatively analysed the three-dimensional variations occurred in the intervened areas and adjacent tissues. Variables related to thickness, area and volume representing the changes between T0 and the different postoperative follow-ups were computed. A CBCT exam allowed to access pre (T0) and postoperative (T3) parameters such as buccal bone thickness (BT), buccal plate height (BH), palatal plate height (PH) and the distance between them (BPD). XIV Results: The linear measurements showed a total mean change in thickness at T1, T2 and T3 of -0,45±0,51mm, -0,46±0,39 and -0,52±0,38, respectively. Buccal volume variation at T1, T2 and T3 was -7,20±6,62%, -7,82±6,86% and -9,52±7,44%, respectively. A mean variation on BPD of -1,50±1,09mm was observed at T3 and after 1-year of treatment subjects with BT≤1mm exhibited a significantly increased buccal thickness variation (-0,48±0,28mm) than patients with BT>1mm (-0.17± 0,11mm) (p=0,049). A multi-variate regression analysis proved a statistical significant influence of BT and BPDT0 on thickness and volume variations after 4 months, whereas no statistical significance was found on BID effect. A positive linear correlation was detected between BPD variations (T0-T3) and total thickness and volume alterations at T1, T2 and T3. Conclusion: After the first year of treatment following flapless single immediate implant placement in maxilla, peri-implant tissues showed a continuous alterations resulting in a thickness change that occurred mainly in the first month and tended to be stable after the fourth month. Thickness and volume variations were significantly influenced by initial buccal bone thickness.
Description
Keywords
Implantes dentários Perda óssea alveolar Tomografia computorizada por feixe cónico Imagiologia tridimensional Scanner intraoral Tecidos peri-implantares Análise volumétrica Estudo retrospetivo Dental implants Alveolar ridge augmentation Alveolar bone loss Cone beam computerized tomography Wound healing Three-dimensional imaging Treatment outcome Maxilla Retrospective study