A retrospective case series evaluating the outcome of implants with low primary stability

Abstract

Objectives There is a need of more studies on whether low primary implant stability would negatively influence the success of implant therapy. Therefore, this retrospective study analyses outcomes of implants placed with low primary stability and factors that may be related to implant failures. Material and methods This retrospective study included 156 patients, restored with 169 implants that presented manual rotation within an observed follow‐up time of a minimum of 34 days and a maximum of 9.28 years. Descriptive statistics, survival analyses (life tables and Kaplan–Meier estimates) and radiographic assessment based on marginal bone level measurements were performed. This original study was adherent to STROBE guidelines. Results Seven implants failed in seven patients, rendering cumulative survival rates of 94.74% (95% CI: 89.11–97.50) and 94.33% (95% CI: 88.30–97.30) at implant and patient levels, respectively. Kaplan–Meier estimates showed implant loss was found only in advanced surgery group (7 implant loss in 82 implants) when compared with simple surgery group (no implant loss in 87 implants; p = 0.005). Conclusions Within the limitations of this retrospective study, implant placement with low primary stability might not negatively affect either the survival rates or marginal bone level changes of implants provided that a protected and unloaded healing is guaranteed.

Immediate loading of fixed partial prostheses reconstructed using either tapered or straight implants in the posterior area: A randomized clinical trial

“…Though several previous preclinical and clinical studies have found successful osseointegration even in loosely placed implants that completely lack initial mechanical stability, 3,15,17 clinicians still focus Two SI group implants which showed insertion torque lower than 30 Ncm were regarded as immediate loading failure and excluded. These implants were submerged for 3 months, and delayed loading protocol was applied.…”

“…3,15,16 Furthermore, a recent retrospective clinical study found the long-term success of loosely placed implants when they were left undisturbed for several months before loading. 17 However, since it is not possible to leave implants undisturbed in the immediate-loading protocol, it is still important to achieve sufficient initial stability. Successful outcomes of immediate loading have mainly been reported in cases of full-mouth rehabilitation with overdentures, since the cross-arch stabilization achieved by splinting was thought to minimize micromotion of the implants.…”

The Effectiveness of Osseodensification Drilling Protocol for Implant Site Osteotomy: A Systematic Review of the Literature and Meta-Analysis

“…The evolution of the techniques and materials adopted has allowed more doctors and patients to use this type of therapy, making possible the placement of implant elements in very hard situations where only a few years ago the professional would have chosen a different therapeutic choice [ 36 ]. One of the main principles for successful therapy is the achievement of suitable primary stability during the implant placement [ 37 ] in respect to the biology of the host [ 38 ] and factors depending on the invasiveness of the operation; the more the preparation of the implant site will be performed in an atraumatic way by avoiding the overheating, and so the necrosis of the site, the more we will be able to respect tissues of the host by avoiding intra- and post-operation complications (bleeding, swelling, local infection, invasion of the noble structures adjacent to the surgery, implant early loss, inadequate healing of hard and soft tissues involved during the operation, presence and/or formation of pus immediately after the operation, pain, alteration of the sensitivity of the area) [ 39 , 40 , 41 ].…”

“…After the surgery, we may assess the primary stability of the placed implants, a value that indicates the contact of the implant surface with the surrounding bone [ 42 ]; after this, the secondary stability will follow, which is reached after the processes of remodeling and healing of the bone [ 43 ]; usually, the achievement of good primary stability will be followed by correct secondary stability [ 44 ]. In this way, the dynamic functional response of the bone tissue is determined by the bone-to-implant contact percentage (BIC), which is constantly interested in remodeling processes under the functional loading [ 25 , 26 , 40 , 41 , 42 , 43 , 45 , 46 , 47 , 48 ]. In order to assess the implant stability, we may use an index called the implant stability quotient (ISQ), a unit of measurement, which allows us to assess the degree of integration of the placed implants [ 49 ]; the clinical range of the ISQ is ranged between 55 and 80, and if the value is higher than 65, it is commonly accepted as a favorable situation for implant stability; on the contrary, values under 45 are considered as insufficient implant stability [ 42 ].…”

Secondary stability achieved in dental implants with a calcium‐coated sandblasted, large‐grit, acid‐etched (SLA) surface and a chemically modified SLA surface placed without mechanical engagement: A preclinical study

“…In the same vein, delayed loading might be safer given that a mature bone structure lining the fixture surface was observed histologically and high ISQ and IST values were observed at 4 and 8 weeks, which is consistent with the findings of previous preclinical experiments (Jung et al, 2012, 2014). The safety of delayed loading was also verified by a recent retrospective clinical study, which found favourable osseointegration and survival rates for implants with a SLA surface that exhibited rotational movements when they were first placed (Lee et al, 2019).…”