Effect of different implant placement depths on crestal bone levels and soft tissue behavior: A 5‐year randomized clinical trial

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.

Dimensiones de la cresta ósea vestibular en incisivos maxilares con indicación de implantes inmediatos. Un estudio transversal y sus implicaciones en el plan de tratamiento.

“…En la actualidad, la utilización de implantes con cambios de plataforma y las conexiones cónicas han sido consideradas como las más indicadas para el tratamiento de los sectores estéticos. Por ello se ha sugerido dejar el implante 1 a 2 mm subcrestal con la finalidad de prevenir la pérdida del hueso (13,18) . Los resultados obtenidos, podrían sugerir que la longitud de implante más acertado a utilizar para tratar esta zona de forma inmediata a la extracción sería el de 13 mm de longitud, y este serviría tanto para el incisivo central como para el lateral, sin distingo entre edad o género, ya que no se aprecian diferencias significativas al comparar los grupos.…”

“…Estudios recientes han determinado una menor pérdida de hueso marginal crestal al implante cuando la profundidad del implante se ubica a 1 o 2 mm subcrestal, lo que sería determinante para obtener un resultado estético predecible (13,18) . Esto nos indicaría la necesidad de conocer la anatomía del hueso alveolar previamente a la extracción dentaria, con la finalidad de poder realizar una correcta planificación de la posición final del implante, permitiendo ofrecer rehabilitaciones estéticas predecibles y duraderas.…”

Biological Oriented Immediate Loading: A New Mathematical Implant Vertical Insertion Protocol, Five-Year Follow-Up Study

“…Implant stability was evaluated with Osstel Device System (Integration Diagnostic, Gothenburg, Sweden). Implants with an implant stability quotient (ISQ) < 60, were excluded from this study, following the scientific literature which suggested that, to achieve a good implant primary stability, an ISQ value of more than 60 should be chosen as the minimum value for immediate loading [ 10 , 33 ].…”

“…Implants failure is usually related to the development of peri-implantitis associated with bone loss around the implant [ 7 ]. A current major challenge is to minimize the marginal bone loss (MBL) around implants, since it has been proven to be important for soft tissue stability and long-term success, as the resorption can trigger bacterial colonization of the coronary part of the implant [ 8 , 9 , 10 ]. Studies in literature suggested that MBL is influenced by the implant location with respect to the bone crest, the amount of keratinized mucosa and the soft tissue thickness [ 11 , 12 , 13 , 14 ].…”

“…The subcrestal placement of dental implants may avoid exposure of implant threads after initial physiologic bone remodeling and allow an adequate aesthetic emergence profile for the prosthetic restoration, with a positive impact on the papillae formation [ 10 , 12 ].…”