IADR Abstract Archives
A Comparison of Bone-level and Tissue-level Implants
Objectives: Currently there is no clear indication on use of on bone-level (BL) and tissue-level (TL) implants. The ideal outcome of this review would create the framework of clinical implant protocols for BL and TL implants, allowing for a more evidence-based driven decision process.
Methods: Scientific literature was reviewed to create parameters for clinical indication of one system over the other. A total of 30 articles including systematic reviews and meta-analysis were used.
Results: Current literature reveals 50% less marginal bone loss surrounding BL implants as compared to TL implants. Microbiological and immunological studies revealed differences between the environment surrounding healthy implants and teeth. Of significance, numerous species common to subgingival plaque are found in the sulcus adjacent to otherwise healthy implants. There is evidence indicating increased levels of pro-inflammatory mediators (TNF-alpha and IL-beta), as well as anaerobic bacterial populations around implant sites as compared to natural tooth sites. Furthermore, the literature reveals lower levels of marginal bone loss and lower incidences of peri-implantitis in patients that adhered to 6 month implant hygiene protocols. In a randomized control trial, TL possessed 1.1mm more keratinized tissue than BL on average.
Conclusions: Within the limitations of the current literature, BL implants preserve more marginal bone compared to TL implants. The implant-abutment junction for BL implants is closer to the crest of alveolar bone and consequently favors pathogenic anaerobic bacteria that cause the upregulation of host inflammatory cells following the final restoration. However, TL implants present with transgingival access for periodontal pathogens to elicit release of host's pro-inflammatory cytokines that disrupt osseointegration during implant healing periods. It has been shown that TL have more keratinized tissue than BL surrounding the implant. Presence of keratinized tissue has been associated with improved peri-implant hygiene.
Methods: Scientific literature was reviewed to create parameters for clinical indication of one system over the other. A total of 30 articles including systematic reviews and meta-analysis were used.
Results: Current literature reveals 50% less marginal bone loss surrounding BL implants as compared to TL implants. Microbiological and immunological studies revealed differences between the environment surrounding healthy implants and teeth. Of significance, numerous species common to subgingival plaque are found in the sulcus adjacent to otherwise healthy implants. There is evidence indicating increased levels of pro-inflammatory mediators (TNF-alpha and IL-beta), as well as anaerobic bacterial populations around implant sites as compared to natural tooth sites. Furthermore, the literature reveals lower levels of marginal bone loss and lower incidences of peri-implantitis in patients that adhered to 6 month implant hygiene protocols. In a randomized control trial, TL possessed 1.1mm more keratinized tissue than BL on average.
Conclusions: Within the limitations of the current literature, BL implants preserve more marginal bone compared to TL implants. The implant-abutment junction for BL implants is closer to the crest of alveolar bone and consequently favors pathogenic anaerobic bacteria that cause the upregulation of host inflammatory cells following the final restoration. However, TL implants present with transgingival access for periodontal pathogens to elicit release of host's pro-inflammatory cytokines that disrupt osseointegration during implant healing periods. It has been shown that TL have more keratinized tissue than BL surrounding the implant. Presence of keratinized tissue has been associated with improved peri-implant hygiene.