ABSTRACT
OBJECTIVES: This randomized clinical trial analyzed the long-term (5-year) crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the anterior mandibular region at different depths (equi- and subcrestal). MATERIALS AND METHODS: Eleven edentulous patients were randomly divided in a split-mouth design: 28 equicrestal implants (G1) and 27 subcrestal (1-3 mm) implants (G2). Five implants were placed per patient. All implants were immediately loaded. Standardized intraoral radiographs were used to evaluate crestal bone (CB) changes. Patients were assessed immediately, 4, 8, and 60 months after implant placement. The correlation between vertical mucosal thickness (VMT) and soft tissue recession was analyzed. Sub-group analysis was also performed to evaluate the correlation between VMT and CB loss. Rank-based ANOVA was used for comparison between groups (α = .05). RESULTS: Fifty-five implants (G1 = 28 and G2 = 27) were assessed. Implant and prosthetic survival rate were 100%. Subcrestal positioning resulted in less CB loss (-0.80 mm) when compared to equicrestal position (-0.99 mm), although the difference was not statistically significant (p > .05). Significant CB loss was found within the G1 and G2 groups at two different measurement times (T4 and T60) (p < .05). Implant placement depths and VMT had no effect on soft tissue recession (p > .05). CONCLUSIONS: There was no statistically significant difference in CB changes between subcrestal and equicrestal implant positioning; however, subcrestal position resulted in higher bone levels. Neither mucosal recession nor vertical mucosa thickness was influenced by different implant placement depths.
Subject(s)
Alveolar Bone Loss , Dental Implants , Mouth, Edentulous , Dental Implantation, Endosseous , HumansABSTRACT
OBJECTIVES: This randomized clinical trial analyzed crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the mandible anterior region at different depths (equicrestal and subcrestal). MATERIALS AND METHODS: Eleven edentulous patients (five implants per patient) were randomly divided in a split-mouth design: G1, 28 equicrestal implants; and G2, 27 subcrestal implants. All implants were immediately loaded. Correlation between keratinized tissue width (KTW) and vertical mucosa thickness (MT) with soft tissue recession was analyzed. Intraoral radiographs were used to evaluate crestal bone changes. Patients were assessed immediately, 4-, and 8-months after implant placement. Rank-based ANOVA-type statistical test was used for comparison between groups (α = 0.05). RESULTS: Fifty-five implants (G1 = 28 and G2 = 27) were assessed in 11 patients. Implant survival rate was 100% for both groups. Both tested implant placement depths presented similar crestal bone loss (P > 0.05). Significant crestal bone loss for each group was found in the different measurement times (T4 and T8) (P < 0.05). Implant placement depths, KTW, and vertical MT had no effect on soft tissue recession (P > 0.05). CONCLUSIONS: Different implant placement depths do not influence crestal bone changes. Soft tissue behavior is not influenced by different implant placement depths or by the amount of keratinized tissue.
Subject(s)
Alveolar Process/anatomy & histology , Bone-Implant Interface/physiology , Dental Implantation, Endosseous/methods , Gingiva/physiology , Aged , Humans , Middle AgedABSTRACT
Objetivo: este estudo foi idealizado com a finalidade de comparar as posições dos análogos em modelos de gesso, obtidos antes e após o procedimento cirúrgico de instalação dos implantes, em dez casos clínicos. Material e métodos: foram selecionados dez guias prototipados de maxilas edêntulas, que já haviam sido utilizados para a instalação guiada de implantes e que já estavam com as próteses instaladas. Cilindros posicionadores de análogos de minipilar foram adaptados para obtenção dos modelos de gesso pré-cirúrgicos (modelo 1). Também foram reunidos os modelos dos casos que haviam sido obtidos através da moldagem realizada em boca após a instalação dos intermediários (modelo 2). Todos foram submetidos a escaneamento a laser, e a comparação entre os modelos foi realizada virtualmente com um software específico. Os dados foram analisados estatisticamente utilizando o teste de Wilcoxon (p < 0,05). Resultados: foi encontrada uma média de desvio angular de 3,17o ± 1,78o (p=0,000). A média do desvio angular encontrada na comparação entre os dois modelos avaliados foi semelhante a desvios encontrados na literatura. Conclusão: técnicas como a da adaptação passiva devem ser utilizadas com o objetivo de compensar tais desvios e facilitar o procedimento técnico laboratorial, entregando a prótese final em menos tempo.
Objective: this study compared the positions of the analogs in plaster models obtained before and after implant placement in 10 clinical cases. Material and methods: ten CAD/CAM surgical guides for maxillary edentulous patients were selected and which had already been used for the guided implant placement and with the final prosthesis already fabricated. To generate the pre-surgical cast model (model 1), mini conical replicas were mounted on the guiding sleeves using cylinder positioners. The models obtained through an impression after the surgical procedures were also analyzed (model 2). Each plaster model was subjected to laser scanning and the comparison between models was performed in specialized software. The statistical analyses were performed using Wilcoxon test (p < 0.05). Results: a mean angular deviation of 3.17o ± 1.8o (p=0.000) was found. The average angular deviation found in the comparison between the two models evaluated was similar to deviations in the literature. Conclusion: techniques such as passive adaptation, must be used in order to compensate the deviations and improve laboratory procedures, speeding the final denture delivery in less time.
