The long-term success of dental implant restorations is dependent on customised and focussed follow-up protocols taking into consideration the risk predictors that may influence the outcome using a team approach. A risk predictor is any factor that may influence and increase the chances of the disease occurring. The proposed maintenance regime should be considered when the implant treatment is planned and should take into consideration the risk factors that are established during the generic and site-specific planning phases. The patients’ journey through this planned pathway will help to establish the risk predictors that will need to be taken into account when planning the maintenance regime. This early consideration will foster a preventive approach with careful case selection, preoperative patient education and risk assessment to manage and control the identified risk factors and predictors implicated in the increased risk of both biological and technical implant-related complications covered in previous chapters. The approach will help identify patients at risk of these complications especially peri-implant disease at the outset and the patient engaged into the discussion prior to any intervention being started. Concerns with patient compliance should be taken into consideration before any implant treatment is executed until the patient understands and accepts responsibility for the aftercare following completion of the treatment. The need for stringent maintenance protocols for the ‘at risk’ patient is even more important and is driven by the differences between implants and teeth where the latter are more resistant to disease progression unlike implants where disease progression is often rapid due to the lack of the periodontal ligament and variation in the vascularity.
Maintenance care, also known as supportive therapy, is defined as the continuous care initiated after the completion of active treatment at regular intervals aimed at ensuring that the health of the tissues is monitored and maintained, and deviation from health identified early so that timely intervention can be implemented to minimise the risk of the problem worsening (Figure 7.1). The problems around implants will fall into two categories, those related to technical issues and those related to biological issues, both of which have been previously discussed (see Chapter 6). The key aims of a maintenance visit are to:
- Monitor the tissues around the implants (visual and clinical assessment)
- Identify problems early and intervene as necessary
The visit is crucial to carry out timely intervention which helps minimise the risk of disease progression as failure to implement treatment is likely to result in progressive and rapid bone loss with ultimate implant loss. Patients should be monitored at customised time intervals based on their risk profile and ideally each visit should include an assessment of:
- The patients plaque control
- The peri-implant tissues and their status
- The implant-retained prosthesis
The key principles of a maintenance visit are checking the above and executing treatment to maintain and/or manage issues that have been identified. The monitoring should be more stringent during the first year and should be undertaken at least once every 3–4 months, and if the situation remains stable, this can be tailored to longer intervals depending on patient compliance, risk profile and manual dexterity. The assessment undertaken during maintenance should be evaluated against the baseline information recorded following the fit of the prosthesis which is crucial in helping explain future change. It is important to remember that the care provided should be continuous, individualised and undertaken systematically. In order to monitor the disease, an understanding of the signs of disease, the type of implant system and treatment undertaken along with the type of prosthesis and materials used at the soft tissue interface is important. An awareness of the implant soft tissue interface will assist with ensuring confidence when undertaking the maintenance visits. The patient should, ideally, have been given ‘an end of treatment passport’ which contains the following information:
- The teeth being replaced
- The implant system (one piece or two piece)
- The details of implant surgery (date, type, timing, augmentation)
- The details of the prosthesis (date of fit, type – screw retained or cement, type of abutments used, one piece or two piece, the loading protocol used)
- The type of cement used (if cement retained) and if screw retained, the type of driver
- The baseline probing chart and radiograph following the fit of the prosthesis including date recorded
- The risk profile of the patient and specific concerns
- The recommended maintenance regime
- Any other issues of note
Healthy peri-implant tissues should show no redness or inflammation (Figure 7.2a, b), and if bleeding is noted, then this is a sign of early disease. The clinical assessment is multifaceted and includes the patient-related assessment and the clinical assessment. Insufficient clinical skills related to the assessment, planning and judging the design of the prosthesis and ability to recognise key patient-related factors such as parafunction (bruxism), smoking, uncontrolled diabetes and periodontal disease are significant contributory factors towards implant failure. The latter conditions predispose the patient to a greater risk of complications and failure and thus early identification will help mitigate this risk.
Components of Maintenance Care
A typical maintenance care visit should include the following:
- Presenting complaint
The patient’s awareness of any issues should be established. Patients are astute and very aware of what is going on in their mouth and will usually be able to describe changes they have noticed early. It is important that these concerns are heard and relevant measures taken to address them. Specific questions related to the patients awareness of bleeding, looseness or movement of the prosthesis should be asked. Patients may present within the first six months of their prosthesis being fitted complaining of loose crowns. This is usually related to occlusal loading driven by the lack of proprioception around implants which enables the patient to place loads of up to 100 Newtons around implants without realising this. This differential loading can lead to loosening of the crown, and if cemented, the crown will come off and if screw retained, then the screw will come loose. This can also be seen as a late complication in patients with old implant restorations that have been in place for more than five years and as the wear of the natural teeth occurs over time, the implant-retained prosthesis is left in occlusal overload leading to the looseness.
- Update of the medical history and social history
The medical history may change during the course of the follow-up period and should be updated at each visit. Conditions such as late onset diabetes could change within a short period of time, which if uncontrolled, could affect the outcome of the implant treatment, and reduced salivary flow either due to aging or medications can also affect the bacterial biofilms and healing of the mucosal tissues. Other conditions such as oral mucosal disorders which cause soreness of the gingival tissues may affect the patients ability to brush around the area and autoimmune conditions such as rheumatoid arthritis which can affect manual dexterity compromising the daily cleaning can also have a detrimental effect on the health of the tissues around implants. The hormonal changes due to pregnancy have been shown to influence the situation in the mouth and can affect peri-implant tissues. The prevalence of conditions such as dementia is on the rise, and it is important to remember that patients with early and undiagnosed dementia may present during this phase and the need for early recognition is important. The patients’ smoking and vaping history should also be checked.
- Soft tissues:
A visual assessment should be undertaken of the tissues and signs of inflammation (redness, swelling, loss of stippling and sinus tracts) noted. The tissues around implants should be assessed. Any signs of redness will indicate a possible inflammatory lesion (Figure 7.3). Sites with lack of keratinised tissue and mobile mucosal tissue will need to be assessed carefully as these areas will have a tendency to harbour bacteria. These sites are usually associated with bone loss and increased plaque accumulation with recession and inflammation and a higher frequency of bleeding due to the lack of the supracrestal hemidesmosomal attachment (Figure 7.4). The gingival tissue biotype should also be noted especially around the implants with thin biotype usually being associated with lack of keratinised tissue and increased risk of recession. Keratinised gingival tissue provides improved long-term stability and is more resistant to abrasion and enables ease of cleaning.
- Plaque and bleeding indices
This should be assessed at individual sites and also across the whole mouth. The plaque index should be recorded and the indices recommended for use around implants are shown in Table 7.1. Plaque in the site is detected by gently running the probe over the margins around the implant tissue interface and also on the implant and the prosthetic surface. Despite early belief stating that rough surface implants harbour subgingival bacteria and colonisation is influenced by the implant thus contributing to a higher risk of peri-implant disease, there is no evidence to support this belief. Bleeding on probing is a better indicator of the presence of inflammation however, around implants, the nature of bleeding should be considered carefully due to the differences in the soft tissue interface between implants vs teeth with delayed bleeding indicating the possibility of trauma to the delicate soft tissue interface (Figure 7.5). Due to the orientation of the soft tissue, false positives can be elicited when probing around implants, and pressures of 0.15 N have been advocated. Thus, if the bleeding around an implant is a single dot then it is more likely to be related to tissue trauma; however, a continuous line of immediate bleeding is indicative of inflammation. Nevertheless, no bleeding on probing has a high negative predictive value indicating tissue stability. Bleeding around implants should be used in conjunction with other parameters such as the probing depth measurements. Suppuration may be detected around the sites, and although this is not a specific marker of peri-implant disease, its presence should be noted and monitored.
Table 7.1 Plaque Indices Used for Plaque Assessment around Peri-Implant Tissues.
Group Indicated for Scoring Comments O’Leary et al. Mainly teeth but can be used around implants % score Calculated using number of tooth surfaced with plaque divided by the number of tooth surfaces present × 100 Lindquist et al. Mainly for implants 0, 1, 2
0 = no visible plaque
1 = local plaque accumulation
2 = general plaque accumulation > 25%
Mombelli et al. Mainly for implants 0, 1, 2, 3
0 = no visible plaque
1 = plaque recognised by running probe over smooth margin of implant
2 = visible plaque
3 = abundance of soft matter
- Probing depths
The use of probes around dental implants was controversial with challenges associated with the type of probe to use with plastic probes specifically designed for use around implants being advocated. However, it is now accepted that metal probes such as the UNC15, if used correctly, will not damage the implant surface or the soft tissue interface. Probing is now accepted as an important and reliable diagnostic tool in the longitudinal monitoring of the peri-implant tissues. The measurements should be recorded from the mesiobuccal running to the distobuccal and then from the mesiopalatal to the distopalatal using a reference point from which to measure the depth and a six point chart being recorded. The probing measurement should use a fixed reference point against which all future depths assessed. The access to the site for probing will also be dependent on the design and shape of the prosthesis and any challenges should be documented (Figure 7.6). The baseline probing depths should be recorded once the prosthesis is fitted and future recordings measured against this. Unlike teeth, there is no standard probing depth around implants due to the parallel nature of the long junctional epithelium resulting in the probing being down to bone as well as the different depths to which implants are placed. The depth of penetration of the probe will be dependent on the pressure used as well as the shape of the prosthesis and the connection to the implant (internal or external), the design of the system (one piece or two
- Plaque and bleeding indices