Influence of Interimplant Distance on Papilla Formation and Bone Resorption: A Clinical-radiographic Study in Dogs

Abstract

Implant esthetics has been the focus of attention for the past decade, and one vital issue is the effect of interimplant distance on interimplant papilla formation and crestal bone loss. The aim of this study was to evaluate the effect of 1, 2, and 3 mm of interimplant distance on papilla formation and crestal resorption in submerged and nonsubmerged Ankylos implants after prosthetic restoration. Bilateral mandibular premolars of 7 dogs were extracted, and after 12 weeks each dog received 8 implants. Implants were placed so that 3 interimplant distances were created at 1 mm (group 1), 2 mm (group 2), and 3 mm (group 3). The sides and the position of the groups were randomly selected. Twelve weeks after placement, the implants received metallic prostheses that allowed 5 mm of space between the prosthetic contact point (CP) and the crestal bone (CB). After 8 weeks, the distance between the CP and the papilla (CP-P) and the gingival height at the distal proximal aspect of the prosthesis (CP-DE) was clinically measured. Radiographic images were obtained to measure the distance of the CP to the CB within the interimplant surfaces (CP-IP) and adjacent to the edentulous surfaces (CP-ED). The clinical measurement of CP-P for submerged and nonsubmerged implants was 3.57+/-1.17 mm and 3.10+/-0.82 mm for group 1, 3.57+/-0.78 mm and 3.16+/- 0.87 mm for group 2, and 3.35+/- 0.55 mm and 3.07+/-0.93 mm for group 3. The CP-DE was 3.25+/-0.77 mm for submerged and 2.78+/- 0.64 mm for nonsubmerged implants. The CP-IP for the submerged and nonsubmerged implants was 6.91+/-0.95 mm and 7.68+/-2.73 mm for group 1, 7.46+/-1.43 mm and 5.87+/-1.71 mm for group 2, and 7.72+/-0.81 mm and 7.59+/-1.33 mm for group 3. The CP-ED was 6.77+/-1.33 mm for submerged implants and 6.03+/-1.58 mm for nonsubmerged implants. There were no statistical significant differences for any of the measured parameters. We conclude that when the distance from the CP to the CB was 5 mm, interimplant distances of 1 to 3 mm did not affect papilla formation or crestal resorption of submerged or nonsubmerged implants in the dog model.

Influence of Interimplant Distances and Placement Depth on Papilla Formation and Crestal Resorption: A Clinical and Radiographic Study in Dogs

“…Tarnow et al 27 also found differences when the interimplant distances of 3 mm or less were compared with those greater than 3 mm, and this could possibly be because their study was based on radiographs from the anterior maxilla, where the alveolar ridge is often narrower than the dog posterior mandibles. On the other hand, the present results are in accordance with the work of Novaes et al 28 and Oliveira et al,7 who found that interimplant distances of 1 to 3 mm did not affect papilla formation or crestal resorption in dog models.…”

“…Studies have been conducted in recent years with the aim of establishing the ideal treatment plan for implants placed in the esthetic zones, with special attention to the position of the contact point in relation to the bone crest and the interimplant distance. According to the results of the present study, when the contact point of restored contiguous implants is placed 3 mm above the bone crest, the interdental papilla formation achieved better indexes when compared with previous studies using the same animal model 6,7 ; in reality, the embrasures were almost closed with soft tissue, and there is some possibility to get the total fill if longer healing periods had been used. Moreover, no significant differences between the interimplant distance of 2 and 3 mm were obtained in relation to papilla formation and crestal bone resorption with the nonsubmerged protocol with Morse cone connection implants with platform switching or shifting.…”

“…The establishment of a biological seal around implants is considered an important natural phenomenon, but it has also been theoretically linked to bone remodeling. 1,3,4 Recent studies in dogs [5][6][7] suggested that the distance between the contact point and crestal bone tip should be about 3 mm, to compensate for the crestal bone resorption that occurs around adjacent implants. However, other factors can contribute to the crestal bone resorption, such as the anatomy of the cervical region and surface treatment of the implants, the type of connection between implant and prosthetic component, the implant positioning in relation to the crestal bone, and the distance between contiguous implants, to name a few.…”

Influence of interimplant distances and placement depth on peri‐implant bone remodeling of adjacent and immediately loaded Morse cone connection implants: a histomorphometric study in dogs

“…Additionally, the implant positioning in relation to the crestal bone may affect the height of the alveolar crest between adjacent implants, especially considering two‐piece implant systems. This may be related to the establishment of the biologic seal through epithelial and connective tissue attachment around the cervical area of the implants (Oliveira et al 2006). Hämmerle et al (1996) studied the effect of the SCL placement of polished surfaces of non‐submerged implants on marginal soft and hard tissues in humans.…”

Prosthetic restoration of the canine

“…Unfortunately the buccal anatomy of the maxilla in the canine area when the tooth has been missing for any length of time is concave, often excessively above the area where the canine bulge ought to be. Because the quantity of bone palatally is always sufficient and they fear they will risk fenestration, if they place the implant too close to cortical buccal bone, oral surgeons are tempted to position their implants with the apex too far palatally, which often makes the pivot emerge too far buccally 6,7,9,14,26,47 (fig. 7).…”