Prospective randomized clinical trial evaluating the effects of two different implant collar designs on peri‐implant healing and functional osseointegration after 25 years

Abstract

Objectives Evaluate the effects of two different machined‐collar lengths and designs on peri‐implant healing. Material and Methods An implant with a microtextured surface and 3.6mm‐long internal‐connection machined collar was compared to two implants that had an identical 1.2mm‐long external‐connection machined collar, but one had the microtextured surface while the other's was machined. Participants received the three implants, with microgap at the crest, alternately at five sites between mental foramen, and a full‐arch prosthesis. Peri‐implant bone levels were measured after 23 to 26 years of function. Keratinized tissue height, plaque, probing depth, bleeding, and purulence were also evaluated. Descriptive and mixed models for repeated\measures analyses were used, with Bonferroni correction for pairwise comparisons. Results Twenty‐two participants (110 implants) were evaluated at the 25‐year examination. Microtextured implants with the longer machined collar had significantly greater mean marginal bone loss (−1.77mm ± 0.18, mean ± SE) than machined (−0.85mm ± 0.18, p < .001) and microtextured (−1.00 ± 0.18mm, p < .001) implants with the shorter machined collar. Keratinized tissue height was greater for internal‐connection (0.74mm ± 0.10) versus external‐connection (0.51 ± 0.08, p = 0.01) microtextured implants. No differences were observed for plaque (p = 0.78), probing depth (p = 0.42), bleeding (p = 0.07), and purulence (p = 1.00). Implant survival rate was 99%. Conclusions Implants with the 1.2mm machined collar limited bone loss to 1mm, while those with the longer machined collar showed > 1.5mm loss after 25 years of function with microgap at the crest. Internal‐connection design and fixture surface microtexturing did not result in greater bone preservation. ClinicalTrials.gov Identifier: NCT03862482.

Dental implant macrodesign features in the past 10 years: A systematic review

“…used implants with a diameter of 3.75 mm and compared implants with smooth collar to the microtextured collar. [ 28 ]…”

“…and Camarda et al , the use of a machined collar showed better results in maintaining marginal bone height than microthreaded or microtextured implant collar. [ 21 , 28 ] Apart from the results of measuring the marginal bone height, Camarda et al . found that the PD and bleeding index in the machined collar group had slightly better results than the microtextured collar group.…”

“…found that the PD and bleeding index in the machined collar group had slightly better results than the microtextured collar group. [ 28 ]…”

Indirect repair of saliva‐contaminated materials using veneering ceramics

“…This is the first study to evaluate the efficacy of the applied surface conditioning liquid for the repair of chipping fractures. Ceramic chipping is the most prevalent technical complication (followed by framework fractures) among fixed dental restorations 1–3,18 . In single‐implant crowns, the 5‐year incidence data reported in the literature shows veneering ceramic chipping rates of 2.9% for metal‐ceramic and 2.8% for zirconia‐ceramic restorations 9 .…”

“…cal success for partially and fully edentulous patients over the last three decades. 1,2 Dental ceramics are widely used in these types of restorations for veneers on metal or ceramic frameworks, and even in monolithic restorations, due to their good esthetics, natural appearance, and favorable optical properties. [3][4][5] Although designs and manufacturing techniques have evolved remarkably, chipping of the veneering ceramic or framework fracture, still occur independent of the material.…”