Stefanie Raes

Immediate loading in partially and completely edentulous jaws: a review of the literature with clinical guidelines

The introduction of immediate loading was a paradigm shift in implant dentistry as it was previously believed that an unloaded period was essential for bone healing in order to promote osseointegration. However, this belief could not be confirmed by clinical studies or by human histology. Hitherto, numerous reports have been published on immediate loading in various indications. An important factor for success is primary implant stability. The latter can be improved by adapting drilling protocols to enhance lateral compression of the bone and by using tapered implant designs with apical thread fixation. To some extent, the use of implants with a microrough surface and rigid splinting may compensate for suboptimal stability. It is important to avoid fracture of the provisional restoration at all times as this may result in local overloading and implant failure. Also, unevenly distributed occlusal contacts may contribute to failure and therefore occlusion ought to be evaluated at every occasion, especially during the early phase of healing. Taking these aspects into account, immediate loading in the fully edentulous mandible by means of an overdenture has been shown to be predictable in terms of implant survival (94.4-100%). However, the procedure may result in additional costs as a result of the need for repeated relining. In addition, the scientific basis for this treatment concept in the maxilla is very scarce. Immediate loading in the fully edentulous jaw by means of a fixed prosthesis is a well-documented treatment concept. In the mandible, three implants have been shown to be insufficient, given the failure rate of up to 10%. With at least four implants a failure rate of 0-3.3% may be expected. In the maxilla, four to six implants could be too limited, given the failure rate up to 7.2%. Increasing the number of implants may reduce implant failure to 3.3%. Provisional fixed prostheses are particularly prone to fracture in the maxilla and hence reinforcement is warranted. Immediately loaded single implants have lower survival rates, of 85.7-100%, with no clear impact of occlusal contact. In fact, a meta-analysis demonstrated a five times higher risk of failure for immediately loaded single implants when compared with delayed loading. No study showed superior soft-tissue preservation or esthetics following immediate loading of single implants compared with other loading protocols. However, this finding may not imply that a provisional implant crown becomes redundant when soft-tissue conditioning is deemed necessary. Taking into account earlier factors for success, immediate loading in the partially edentulous jaw by means of a fixed prosthesis seems predictable in terms of implant survival (95.5-100%). However, there are no studies with data on soft-tissue parameters, esthetic aspects or patient-centered outcomes, and the available studies mainly relate to the load-carrying part of the dentition. Clinical studies focusing on these aspects of treatment outcome are clearly needed. High patient satisfaction is the most important advantage of immediate loading, especially during the early healing phase. In this context, one should also realize that studies have revealed comparable patient satisfaction in patients following delayed loading once their prosthesis is in place. In the decision-making process, this aspect should be properly discussed with the patient along with other advantages and disadvantages of immediate loading.

Clinical outcome after 8 to 10 years of immediately restored single implants placed in extraction sockets and healed ridges

Recent systematic reviews point to the scarcity of single implants followed up longer than 5 years, and the incidence of biologic/technical complications is underreported. This prospective follow-up study documents 8- to 10-year clinical outcomes of immediately restored single implants in extraction sockets (immediate implant treatment [IIT]) and healed bone (conventional implant treatment [CIT]). Patients received a single, chemically modified, moderately rough titanium implant and a provisional crown on the day of surgery in the anterior maxilla (second premolar to second premolar). Provisional crowns were replaced by permanent crowns after 10 weeks. Implant survival, complications, crestal bone changes, plaque score, probing depth, and bleeding on probing were regularly recorded up to 10 years of follow-up. Of 16 patients who underwent IIT, 11 could be evaluated after 8 years. Of the 23 patients who received an implant in healed bone, 18 were finally evaluated. One implant failed in the IIT group at 12 weeks; all implants survived in the CIT group; 38% of the patients experienced at least one complication; 10% had one or more biologic complications, whereas 31% experienced one or more technical complications. There were no significant changes in crestal bone level from 1 to ≥ 8 years of follow-up for either group or between IIT and CIT at any time point (P ≥ .129). Only 6.9% (2 of 29) implants demonstrated progressive bone loss > 2 mm combined with pockets ≥ 6 mm. Immediately restored single implants in extraction sockets and healed ridges demonstrate good long-term outcomes in terms of implant survival, crestal bone loss, and peri-implant health. However, biologic and especially technical complications are common.

A long-term prospective cohort study on immediately restored single tooth implants inserted in extraction sockets and healed ridges : CBCT analyses, soft tissue alterations, aesthetic ratings, and patient-reported outcomes

BACKGROUND Although many studies have been published on single implants, long-term data remain scarce. PURPOSE To evaluate immediately restored single implants after at least 8 years of follow-up in terms of buccal bone, soft tissue alterations, aesthetic ratings, and patient-reported outcomes. MATERIALS AND METHODS This prospective cohort study included patients who were consecutively treated with an immediately restored single implant installed in an extraction socket (IIT) or a healed ridge (CIT) in the anterior maxilla. Biomaterials were never used. CBCTs were taken at study termination, soft tissue alterations, and Pink Esthetic Score were evaluated between 1 year and study termination using standardized clinical images. Patient satisfaction was also registered. RESULTS About 11/16 initially treated patients in the IIT cohort (10 men, 6 women; mean age 45) and 18/23 initially treated patients in the CIT cohort (12 men, 11 women; mean age 40) could be evaluated after more than 8 years. A buccal bone wall less than 2 mm was found at all implant sites. A thin buccal bone wall less than 1 mm was found at 42% of the implant sites. In the CIT cohort, 8 patients had a missing buccal bone in the crestal area, although bone was present at the time of surgery. Alveolar process deficiency significantly deteriorated (P ≤ .046), whereas vertical soft tissue levels and PES remained stable over time in both cohorts. Patients expressed high overall satisfaction. CONCLUSIONS Substantial dimensional changes may be expected at the buccal aspect of single implants inserted in the premaxilla. As a result, contour augmentation procedures at the time of implant placement should be considered to counteract these bone alterations, even when implants are fully embedded in bone upon insertion.