The moment when implants are put into function is marked by the connection of the implant prosthesis. The choice of the most suitable loading protocol is an important step in the process of treatment planning. When selecting the moment of implant rehabilitation, you are faced with an important clinical decision. This module presents the different criteria for choosing the loading protocols.

An implant loading protocol is defined as the time elapsed between implant placement and the attachment of the prosthesis. After implant placement, the clinician will decide when is the best moment to load the implants. Dental implants are often put into function by means of a provisional prosthesis that will stay in place until the final rehabilitation is delivered.

Early loading of dental implants is defined as the attachment of the prosthesis onto the implant between 1 week and 2 months subsequent to implant placement. In an early loading protocol, the implants are put into function during the later stages of bone healing. The soft tissues are healing in this period and by 2 months, have almost healed completely. This results in reduced treatment time between implant placement and loading.

Conventional or early loading with a provisional prosthesis is often used to: reshape the morphology of the peri-implant soft tissue in line with esthetic considerations, modify the occlusal scheme, evaluate the morphology and function of the planned implant prosthesis. In these cases, implants can be loaded with a conventional or early loading protocol, and the treatment is completed at a later stage with the delivery of the final prosthesis.

Conventional or early loading can also be achieved by attaching the definitive prosthesis. This clinical situation is ideal for cases with low esthetic risk, such as single implants or small fixed dental prostheses in posterior areas with stable occlusion. This approach can significantly reduce the treatment time as there is no need for a provisional phase.

Immediate loading of dental implants is defined as the attachment of the prosthesis onto the implant within one week of implant placement, including the day of surgery. Immediate loading reduces the time of edentulism by the immediate delivery of a provisional prosthesis. In this case, peri-implant bone and soft tissue healing occurs under functional loading.

The use of a provisional rehabilitation is recommended in an immediate loading protocol. The attachment of a provisional implant prosthesis is generally performed immediately after implant placement, or in the following days. These provisionalization techniques are often complex procedures. After using an immediate loading approach, it is recommended to allow the peri-implant bone and soft tissue to heal completely before beginning the final rehabilitation.

Next, we will look at treatment modifiers. Treatment modifiers are clinical factors determined during the diagnostic, planning, surgical, prosthodontic and maintenance phases of treatment that have an influence on the choice of loading protocol. These factors determine specific indications for loading protocols. They are: Patient medical condition and local risk factors: Once the indication of implants has been confirmed, patients with a medical condition such as diabetes, osteoporosis, history of radiotherapy, or risk factors such as smoking, periodontitis, and bruxism, should receive a conventional loading protocol because they are at risk of impaired wound healing. Delaying loading for 2 or more months after implant placement ensures sufficient time for the bone and soft tissues to heal.

Implant primary stability and insertion torque are treatment regulators related to the surgical technique. These two modifiers are determined at the time of implant placement. In optimal conditions, an implant should obtain primary stability at insertion. If an immediate loading protocol is selected, the initial stability should range from 20 to 50 Ncm depending upon the implant system. Resonance frequency analysis or RFA is also a method of measuring these modifiers. RFA with values greater than 55 ISQ would be required before considering immediate loading of an implant.

The following animations illustrate how treatment modifiers are applied in the selection of the appropriate loading protocol. If the patient has a medical condition or a risk factor is present, if implant stability was not achieved or a low insertion torque was measured, if substantial grafting is needed at the time of placement or bone volume allows only for reduced diameter implants to be placed, conventional loading is the selected protocol. Conventional implant loading is predictable in all clinical situations and is particularly recommended in the presence of one or more treatment modifiers.

If the patient is healthy and no risk factors are present, if implant stability was achieved or a high insertion torque was measured, if no or minimal grafting is needed at the time of placement or the bone volume allows for placement of standard diameter implants early or immediate loading can be selected. All these treatment-modifier characteristics should be present to select early or immediate loading. Additionally, there are specific guidelines for loading protocols according to different clinical situations.

Clinical recommendations for selecting the appropriate implant loading protocol are described in the next section according to different clinical situations, as outlined in the results of the 5th ITI Consensus meeting. Specific recommendations are presented for single implant crowns, extended edentulous sites, edentulous jaws to be reconstructed with full-arch fixed dental prostheses or FDPs, and edentulous jaws to be reconstructed with full-arch removable dental prostheses or RDPs.

First, we will look at single implants. The recommendations for the three loading protocols in the different jaw regions will be listed in the table. Conventional implant loading is predictable in all regions of the maxilla and the mandible. For the anterior and premolar regions, early loading of single-implant crowns is a predictable procedure in terms of implant survival and stability of the marginal bone. However, data regarding soft-tissue aspects are not conclusive enough to recommend early loading of single implant crowns in esthetically demanding sites as a routine procedure. Early loading in such sites should be approached with caution and only by experienced clinicians. For the mandibular molar region, early loading is a predictable procedure and can be generally recommended in cases where clinical benefits are identified. The small amount of data available on early loading of single-implant crowns in the maxillary molar region does not allow for a general recommendation of this loading procedure. In these sites, conventional loading should be the procedure of choice. Immediate loading in anterior and premolar regions is predictable in terms of implant survival and marginal bone stability. However, data regarding soft-tissue aspects are not conclusive enough to recommend immediate loading in esthetically demanding sites as a routine procedure. Immediate loading in such sites should be approached with caution and only by experienced clinicians. According to the ITI SAC Classification immediate loading is considered an advanced to complex treatment. For the mandibular molar region, immediate loading is a predictable procedure and can be generally recommended in cases where clinical benefits have been identified. There is only little data on immediate loading of single-implant crowns in the maxillary molar region. Therefore this loading procedure cannot be generally recommended. In these sites, conventional loading should be the procedure of choice.

Now let’s look at loading protocols in extended edentulous sites. Conventional implant loading is predictable in every part of the maxilla and the mandible. In the absence of modifying factors, early loading of solid-screw type implants with a microtextured surface after four to eight weeks is a predictable treatment approach. Immediate loading of implants placed into healed, extended edentulous sites in the posterior regions seems to be predictable. However, in such cases immediate implant loading is of limited clinical benefit. Immediate loading of implants in anterior sites should be approached with caution and only by experienced clinicians, as insufficient evidence exists to support such treatment.

The treatment of edentulism with FDPs is classified as complex, according to the ITI SAC criteria. Therefore, careful case selection and treatment planning, as well as adequate knowledge, skill, and experience on the part of clinicians performing the procedures are key. Immediate, early, and conventional loading with one-piece fixed interim prostheses have demonstrated high implant-and-prosthesis survival rates and can be recommended for the mandible and maxilla. The patient-centered benefits of immediate loading include the immediate fixed restoration of function, reduction of postoperative discomfort caused by a removable interim prosthesis, as well as reduction of the overall treatment time. The number, size, and distribution of implants for a full-arch fixed prosthesis need to be based on the implant prosthodontic plan, arch form, and bone volume, regardless of the loading protocol.

When managing the edentulous jaw using implants to support or retain a full arch RDP conventional and early loading represent a satisfactory treatment modality and can be recommended as routine in the absence of modifying factors. Immediate loading protocols appear predictable in the mandible. The evidence for immediate implant loading in the maxilla is less compelling.

Module "Loading Protocols", Summary: Loading protocols may influence treatment outcomes. Conventional loading is predictable in all clinical situations. The presence of a single suboptimal treatment modifier calls for conventional loading. Early and immediate loading are indicated when all treatment modifiers are optimal. Selection of a loading protocol must be based on the specific clinical situation.