Minimum Abutment Height to Eliminate Bone Loss: Influence of Implant Neck Design and Platform Switching

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Objective Prosthetic abutment height and peri‐implant mucosal thickness are considered factors that influence marginal bone remodeling during biological width establishment around dental implants. However, no clinical studies have evaluated their simultaneous effect on marginal bone loss (MBL). This study analyzes the influence of abutment height on MBL around implants surrounded by both thin and thick mucosa up to 12 months after prosthetic loading. Material and methods Seventy platform‐switched implants with internal hex were placed equicrestally in two groups of patients with different vertical mucosal thickness: thin (≤2.0 mm) and thick mucosa (>2.0 mm). After three months of submerged healing, prosthetic abutments with a height of 1 mm (short) or 3 mm (long) were randomly assigned for single crown screwed restoration in both groups. MBL was evaluated on radiographs taken at implant placement (T0), restoration delivery (T1), and after 6 months (T2) and 12 months (T3) of loading. Results After 12 months of loading, 66 implants were functioning (two dropouts, two failures), resulting in a 97% survival rate. Compared with T0, mean MBL at T3 ranged between 0.59 and 0.80 mm in short abutment groups and between 0.28 and 0.37 mm in long abutment groups. Differences resulted statistically significant, irrespective of vertical peri‐implant mucosal thickness. The MBL pattern over time showed the greatest amount of bone resorption in the first 6 months after loading, particularly around implants with short abutments. Conclusions Platform‐switched implants restored with short abutments present greater marginal bone loss than identical implants with long abutments, without significant peri‐implant mucosal thickness effects.

Section: Introductionsupporting

confidence: 55%

Section: Introductionmentioning

confidence: 61%

Section: Discussionmentioning

confidence: 91%

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Biological width establishment around dental implants is influenced by abutment height irrespective of vertical mucosal thickness: A cluster randomized controlled trial

Spinato¹,

Stacchi

Lombardi³

et al. 2019

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“…Shorter abutments would be associated with greater peri‐implant marginal bone loss (Galindo‐Moreno et al, ). More recently, another retrospective study observed an inverse relationship between abutment height and peri‐implant marginal bone loss and estimated a height of 2.5 mm as adequate to neutralize the bone loss (Spinato, Galindo‐Moreno, Bernardello, & Zaffe, ). However, a prospective study failed to detect differences between 1 and 2 mm height abutments over a 1‐year follow‐up period (Borges, Leitao, Pereira, Carvalho, & Galindo‐Moreno, ).…”

Section: Discussionmentioning

confidence: 99%

Influence of abutment disconnection on peri‐implant marginal bone loss: A randomized clinical trial

Praça¹,

Teixeira

Rêgo³

2020

Objectives To evaluate the influence of abutment disconnections and reconnections on peri‐implant marginal bone loss. Material and methods Twenty‐four participants received single‐unit implants and were randomly assigned into one of the two groups: the definitive abutment group (DEF), in which the definitive abutments were connected at the same time as the implant was inserted; and as a control, the healing abutment group (HEA), in which the healing abutments were disconnected and reconnected three times, at 8, 10, and 12 weeks after surgery. Peri‐implant marginal bone level was measured through radiographic follow‐up performed immediately after the surgery (baseline), at 8 weeks and after 6, 12, and 24 months. Implant stability and peri‐implant health were assessed by resonance frequency analysis and peri‐implant probing, respectively. Results At the end of 2 years, the mean bone level was −0.18 ± 0.12 mm for the DEF group and −0.13 ± 0.13 mm for the HEA group, resulting in a cumulative bone loss of −0.61 ± 0.10 mm and −0.81 ± 0.15 mm, respectively, with no statistical difference between groups. Bone level changes showed statistically significant differences only between 0 and 2 months (DEF: −0.70 ± 0.12 mm; HEA: −0.36 ± 0.10 mm) and between 2 and 6 months (DEF: −0.11 ± 0.11 mm; HEA: −0.65 ± 0.14 mm). No differences were observed between the groups for implant stability, probing depth, and bleeding on probing. Conclusion Immediate connection of the prosthetic abutments did not reduce bone loss in comparison with three disconnections of the healing abutments.

“…Nevertheless, although the existing unanimity around the platform‐switching concept benefits in terms of MBL reduction, the vertical component of the prosthetic solution seems also to contribute for the MBL outcome. Recent studies report less MBL when abutment height is greater, leading to an increased vertical mismatching that, hypothetically results in more existing space for soft tissue establishment and remoteness of the inflammatory area from the crown/abutment connection, independently of screw‐retained (Galindo‐Moreno et al, ; Verveake et al, ) or cemented‐retained prosthesis (Spinato, Galindo‐Moreno, Bernardello, & Zaffe, ). Also, it is not clear what is the role of the timespan of biological width establishment around dental implants and MBL, as a number of studies correlate the technical features of the implant, the type of abutment, or the timing of provisional prosthesis restoration with the peri‐implant bone‐level changes, disregarding the influence of permanent abutment insertion in the peri‐implant tissue changes (Schwarz, Hegewald, & Becker, ; Suarez, Chan, Monje, Galindo‐Moreno, & Wang, ).…”

Section: Introductionmentioning

confidence: 99%

Influence of the abutment height and connection timing in early peri‐implant marginal bone changes: A prospective randomized clinical trial

Borges

Leitão

Pereira

et al. 2018

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Aim The aim of this study was to compare the influence of the abutment height and insertion timing on early marginal bone loss (MBL) in posterior mandibular partial implant‐supported restorations. Material and methods The study was planned as a prospective, randomized, controlled parallel group including subjects in need of at least two implants for the restoration of an edentulous posterior mandibular area. The patients were allocated into Groups A (implants immediately connected to 2‐mm height abutments), B (immediately connected 1‐mm height abutments), and C (2‐mm abutments were inserted in a second‐stage surgery). Each subject was placed in a 1‐year follow‐up program, including examination assessment of various soft tissue and bone‐level parameters. Results A total of thirty‐three patients, including sixty‐eight implants, were enrolled in this study. One implant was lost on group C after the first month of healing. A mean MBL change of 0.719 ± 0.361, 0.651 ± 0.379, and 0.754 ± 0.672 mm was computed for groups A, B, and C, respectively, with no significant differences found. The early MBL at T1 was an independent predictor variable for the marginal bone alterations that were assessed at T3 (p < 0.001). Conclusion The first‐month MBL variation is a predictor factor of the bone alterations that might occur after 1 year of treatment. The early connection of final prosthetic abutments with distinct heights does not seem to reduce the 1‐year MBL rate when compared with traditional treatment protocols.