Impact of crestal and subcrestal implant placement in peri-implant bone: A prospective comparative study

Abstract

BackgroundTo assess the influence of the crestal or subcrestal placement of implants upon peri-implant bone loss over 12 months of follow-up.Material and MethodsTwenty-six patients with a single hopeless tooth were recruited in the Oral Surgery Unit (Valencia University, Valencia, Spain). The patients were randomized into two treatment groups: group A (implants placed at crestal level) or group B (implants placed at subcrestal level). Control visits were conducted by a trained clinician at the time of implant placement and 12 months after loading. A previously established standard protocol was used to compile general data on all patients (sex and age, implant length and diameter, and brushing frequency). Implant success rate, peri-implant bone loss and the treatment of the exposed implant surface were studied. The level of statistical significance was defined as 5% (α=0.05).ResultsTwenty-three patients (8 males and 15 females, mean age 49.8±11.6 years, range 28-75 years) were included in the final data analyses, while three were excluded. All the included subjects were nonsmokers with a brushing frequency of up to twice a day in 85.7% of the cases. The 23 implants comprised 10 crestal implants and 13 subcrestal implants. After implant placement, the mean bone position with respect to the implant platform in group A was 0.0 mm versus 2.16±0.88 mm in group B. After 12 months of follow-up, the mean bone positions were -0.06±1.11 mm and 0.95±1.50 mm, respectively - this representing a bone loss of 0.06±1.11 mm in the case of the crestal implants and of 1.22±1.06 mm in the case of the subcrestal implants (p=0.014). Four crestal implants and 5 subcrestal implants presented peri-implant bone levels below the platform, leaving a mean exposed treated surface of 1.13 mm and 0.57 mm, respectively. The implant osseointegration success rate at 12 months was 100% in both groups.ConclusionsWithin the limitations of this study, bone loss was found to be greater in the case of the subcrestal implants, though from the clinical perspective these implants presented bone levels above the implant platform after 12 months of follow-up. Key words:Immediate implants, tooth extraction, dental implants, single-tooth, crestal bone, placement level.

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

“…This is in agreement with previous studies that demonstrated no statistically significant difference between the two placement depths tested (Al Amri et al, ; Koh et al, ; Koutouzis et al, ; Palaska et al, ). Although the placement of subcrestal implants was suggested to minimize bone resorption (Barros, Novaes, Muglia, Iezzi, & Piattelli, ; Fetner et al, ; Novaes et al, ; Pontes et al, ; Saleh et al, ; Vervaeke et al, ; Weng, Nagata, Leite, de Melo, & Bosco, ), a study conducted by Pellicer and coworkers found greater bone loss for subcrestal implants (Pellicer‐Chover et al, ).…”

Influence of Apico‐Coronal Implant Placement on Post‐Surgical Crestal Bone Loss in Humans

“…According to a recent 12‐month study, 35 the baseline peri‐implant bone level caused implants placed at the crest of bone to present a greater exposed implant surface (mean 1.13 mm) than implants placed at a subcrestal level (mean 0.57 mm), even though CBL was found to be significantly less in implants placed equicrestally compared with those placed subcrestally. Given that exposed rough implant surfaces could potentially lead to complications in peri‐implant health, 36 the authors suggested subcrestal placement of the implants would be preferable.…”

Soft tissue changes and crestal bone loss around platform‐switched implants placed at crestal and subcrestal levels: 36‐month results from a prospective split‐mouth clinical trial

“…In the present study, CBL was measured on digital radiographs according to the technique presented in a recent study (Pellicer‐Chover et al. ). In the subcrestal group, the level of alveolar bone stayed at a coronal position in relation to the IAJ at 36 months of follow‐up.…”

“…However, contradictory results have also been reported (Pellicer‐Chover et al. ). In a recent experimental study on dogs with ligature‐induced peri‐implant inflammation, Huang et al.…”

“…An explanation in this regard is that subcrestal placement of the implant-abutment interface helps in maintaining the texture and tonality of the soft tissues and also favors the reestablishment of favorable marginal tissue architecture than crestally placed implants (Novaes et al 2009). However, contradictory results have also been reported (Pellicer-Chover et al 2016). In a recent experimental study on dogs with ligature-induced periimplant inflammation, Huang et al (Huang et al 2015) investigated the effect of placement depth on peri-implant CBL.…”