Peri-Implantitis at the Hygiene Visit

Most peri-implantitis is first visible to a hygienist, at a routine visit, in a patient who feels fine. Implants do not ache the way teeth do, the mucosal seal hides bone loss well, and by the time a patient notices something the case is usually harder than it needed to be. The habits below turn a maintenance visit into a screening visit.

Why the Numbers Mean Something Different

Around a tooth, connective tissue fibers insert into cementum perpendicular to the root, and a probe stops at that attachment. Around an implant there is no cementum and no inserting fibers. The collagen runs parallel to the fixture surface, the seal is hemidesmosomal and mechanically weaker, and a probe travels closer to bone at a given force. Add that implants are placed at varying depths in tissue of varying thickness, and a peri-implant probing depth is comparable neither to a periodontal one nor to the implant next to it.

What is comparable is an implant against itself, over time. That is the entire case for baseline records.

Practical technique: use a light force. The World Workshop case definitions specify gentle probing and deliberately put no figure in newtons on it, but Gerber and colleagues found that raising probing pressure from 0.15 N to 0.25 N produced 13.7 percent more bleeding readings at implant sites, and proposed 0.15 N as the threshold for avoiding false-positive bleeding around implants. Light is lighter than most operators think. Six sites per implant. A conventional probe is fine; the material matters far less than force and consistency. Record bleeding on that gentle probing and whether anything expresses. Note erythema, swelling, the width of keratinized mucosa, and whether the patient can physically reach the site. If the crown contour prevents the probe from seating, record that too, because it is a finding about the restoration.

Baseline Records at Delivery, and Why

The most useful thing a restoring office can do for the next decade of that implant is take a proper set of records the day the final crown is seated:

• A periapical radiograph taken with a paralleling technique, threads clearly resolved, which is the evidence the beam was perpendicular. This is the bone-level reference every future film is measured against.
• Circumferential probing depths at six sites, recorded as implant readings, not blended into the periodontal chart.
• Tissue thickness and the width of keratinized mucosa on the facial.
• A photograph, which settles later arguments about recession and contour.
• The system, platform, diameter, and length, kept where the next clinician can find them.

This is the workshop’s own recommendation, not a local preference: the consensus report asks clinicians to obtain baseline radiographic and probing measurements once the implant-supported prosthesis is complete, and a further radiograph after a period of loading to fix the bone level reference. Without those, the 2017 criteria fall back to absolute thresholds, which are conservative and catch disease later than a baseline would.

The 2017 World Workshop Case Definitions

The consensus report of workgroup 4 of the 2017 World Workshop, published jointly by the American Academy of Periodontology and the European Federation of Periodontology and collected with the rest of the proceedings at perio.org, defines three states. The thresholds are worth knowing exactly.

Peri-implant health. No erythema, no bleeding on gentle probing, no swelling, no suppuration. No increase in probing depth compared with previous examinations. No bone loss beyond the crestal change that follows initial bone remodeling. Health can exist with reduced bone support; the diagnosis is about the absence of inflammation, not about the bone level.

Peri-implant mucositis. Bleeding and/or suppuration on gentle probing, with or without an increase in probing depth, and no bone loss beyond the initial remodeling. The lesion is confined to the mucosa. It is plaque-driven and it is reversible.

Peri-implantitis. Bleeding and/or suppuration on gentle probing, plus increased probing depth compared with previous examinations, plus bone loss beyond the crestal change from initial remodeling.

When no previous records exist, which is the common situation, the workshop’s fallback definition is: bleeding and/or suppuration on gentle probing, probing depth of 6 mm or more, and bone level 3 mm or more apical to the most coronal portion of the intraosseous part of the implant.

Two things follow. Mucositis is defined by bleeding, not depth, so a 3 mm site that bleeds is a diagnosis. And peri-implantitis requires bone loss, so nothing is settled without a film.

Reading the Radiograph

Initial remodeling after loading is normally in the region of 0.5 to 1 mm in the first year and close to flat after that; the five-year meta-analysis by Laurell and Lundgren found pooled mean marginal bone level change from the time of prosthetic loading of 0.75 mm or less across the systems it could evaluate. The workshop consensus adds the caveat that the degree of physiological remodeling varies with implant design and protocol, which is why the reference film is the one taken after a period of loading rather than a universal number. Loss that continues beyond the first year is not remodeling.

Compare films of the same geometry. Threads should be crisp and countable on both; a film where the threads blur is angled and cannot be measured against one where they are sharp. Count threads rather than eyeballing, since thread pitch is a built-in ruler. A saucerized, crater-shaped radiolucency around the coronal threads with an intact apical portion is the classic peri-implantitis pattern, and it looks different from the diffuse loss of a failing integration. A periapical shows interproximal bone only; buccal loss, which is where much of it is, is invisible, which is one reason a cone-beam scan is sometimes taken here.

Instruments That Are Safe

On the implant and abutment surface: titanium curettes, PEEK or resin-tipped instruments, titanium-coated ultrasonic tips, a rubber cup with non-abrasive paste, and glycine or erythritol powder air polishing, which is effective subgingivally and gentle on titanium. Floss is fine, though shredded floss left in a sulcus is a known irritant, so it should be pulled through in a single pass rather than sawed. Coated-wire interdental brushes are the workhorse for home care.

Avoid on the implant surface: stainless steel curettes and uncoated ultrasonic tips, sodium bicarbonate air polishing directed into the sulcus, coarse prophy pastes, and acidulated phosphate fluoride, which etches titanium. Calculus on the crown well away from the tissue can be handled normally.

Maintenance Interval

Twice a year is the floor for an implant patient, not the target. Three to four months applies to any patient with a history of treated periodontitis, which the World Workshop review of peri-implantitis by Schwarz and colleagues groups with poor plaque control and absent maintenance care as the three factors carrying strong evidence of increased risk, and to smokers, poorly controlled diabetics, patients with less than roughly 2 mm of keratinized mucosa, anyone whose plaque control is inconsistent, and any implant that has already had mucositis. That same review rates the evidence on smoking and diabetes as inconclusive and the role of keratinized mucosa as undetermined, so the last of those sit here as prudence rather than as established risk. Intervals longer than about five to six months are associated in the literature with higher rates of peri-implantitis; the systematic review and meta-analysis by Monje and colleagues concluded that there is reason to claim a minimum recall interval of five to six months. Where implants were placed here, maintenance alternates between the two offices.

What Mucositis Responds to in the General Practice

Mucositis is a general-practice diagnosis with a general-practice treatment, and it is worth treating seriously, because the workshop consensus takes peri-implant mucositis to precede peri-implantitis, while noting that what tips one into the other has not been identified and that progression is more likely in the absence of regular maintenance.

Debride the site with appropriate instruments, remove every trace of excess cement, polish, and then spend the real time on the two things that decide the outcome: a home-care method the patient can physically perform on that specific implant, demonstrated in the mirror with the interdental brush in their hand, and an honest look at whether the restoration is the problem. An overcontoured crown, a submerged margin the patient cannot reach, a bridge with no cleansable embrasure, or residual cement will defeat any amount of brushing, and those are fixed by the restoring dentist, not by more prophy visits. Re-evaluate at four to six weeks. Antiseptic rinses are an adjunct at best; the evidence does not support them as the treatment. If bleeding persists despite genuinely good plaque control, take a film.

What Warrants a Referral

Send the case when any of these appears:

• Suppuration. Any amount, at any depth. This one does not wait.
• Probing depth of 6 mm or more with bleeding, or any depth that has increased from the patient’s baseline.
• Bone loss of 3 mm or more from the most coronal intraosseous portion of the implant, or any progressive change compared with a prior film.
• Exposed threads, visible or detectable with a probe.
• Mucositis that has not resolved after debridement, corrected home care, and a re-evaluation.
• Mobility of the fixture, which indicates a failed implant rather than peri-implantitis and should be sent promptly. Mobility of the crown or abutment alone is a restorative problem, though it is worth ruling out the other.
• Recession or a gray shadow in the esthetic zone, or a thin or absent band of keratinized mucosa.
• Residual cement that cannot be fully removed in the general practice.
• Pain, swelling, or a sinus tract at any time.

The referral thresholds for teeth and implants together are on referral criteria, and what treatment looks like is described on implant problems. Patients with concurrent periodontitis on the natural dentition usually need both addressed; see gum disease treatment.

What Happens After the Referral

Referred patients are contacted the same business day and offered a consultation within the week. Dr. Verrett, a Diplomate of the American Board of Periodontology and formerly Chief of Periodontics at Elmendorf Air Force Base, evaluates the implant clinically and radiographically, with a cone-beam scan where the buccal plate is in question. A written report goes to the referring office after every visit with the diagnosis, the plan, and the maintenance interval, and the patient returns for restorative care and alternating maintenance. Implants placed here are Nobel Biocare, NobelActive and NobelReplace Conical Connection, but peri-implant disease is treated on any system.

How to refer · For dentists · Lunch and learn — peri-implantitis at the hygiene visit is one of the talks Dr. Verrett brings to referring offices.