Why problems that can arise after an implant (peri-implantitis, screw loosening and prosthesis fracture, altered nerve sensation, maxillary sinus problems, early failure) occur, and what we check on CT before treatment.
Director Jeong Jinwoo · Published 2026.10.08
Summary. Implants are not a treatment free of side effects. The most common problem is inflammation of the gums and bone (peri-implant mucositis and peri-implantitis), followed by mechanical problems such as a loosened screw or a broken prosthesis. Altered nerve sensation in the lower jaw and maxillary sinus problems in the upper jaw are rare, but they are the kind that should be avoided by checking distances on 3D CT before surgery. The proportion still in the mouth after 10 years is reported as about 96%, but “still there” and “never had a problem” are different things. This guide shows you that difference first.
Implant side effects fall into inflammatory (biological) problems, mechanical problems, and problems related to the surgery itself. The table below is organized by the signs a patient notices.
| Problem | When it occurs | How common | Signs the patient feels | What the director checks |
|---|---|---|---|---|
| Peri-implant mucositis | Months to years after fitting | About 43% of people with implants[1] | Red gums, bleeding when brushing | Bleeding on gum probing, no bone loss[6] |
| Peri-implantitis | Years after fitting | About 22% (1–47% across studies)[1] | Swollen gums, pus, unpleasant odor; looseness if late | Increased probing depth + bone loss on X-ray[6] |
| Screw loosening | Any time after fitting | A common type of mechanical problem[8] | The prosthesis moves slightly or food gets caught | Screw tightness, bite |
| Prosthesis fracture or chipping | Years after fitting | Varies by material and position[8] | A sharp feeling when chewing, a piece breaks off | Extent of fracture, whether there is tooth grinding |
| Altered nerve sensation (lower jaw) | Right after surgery | Rare, but reported[9] | Lasting tingling or numbness of the lip or chin | Distance to the nerve canal (CT), course of recovery |
| Maxillary sinus problems (upper jaw) | During or right after surgery | Rare | Pressure toward the nose, blood in nasal discharge, sinusitis symptoms | Distance to the sinus floor (CT), whether the membrane was damaged |
| Early osseointegration failure | Weeks to months after placement | Low overall, but higher depending on smoking and general health[3][4] | The implant is loose or pain does not settle | X-ray, mobility test |
The figures in the table are averages pooled from studies in many countries, and risk differs from person to person. They are not absolute values but a reference for seeing “which problems you should know about before starting.”
Peri-implantitis is the implant counterpart of periodontitis around natural teeth, and the cause is the same: plaque building up around the neck of the implant. Unlike a tooth, an implant is attached directly to the bone and has no fibrous tissue surrounding it, so once inflammation develops it can deepen faster than around a tooth. The first stage, in which only the gum is swollen, is peri-implant mucositis (Korean); once bone starts to be lost, it is called peri-implantitis (Korean).[6]
There are three signs you can notice: bleeding from that area when brushing, gums that look red or swollen, and pus or odor. Pain is actually uncommon, so it is easy to dismiss it as “it doesn’t hurt, so it’s fine.” That is why the European Federation of Periodontology clinical guideline recommends regular checks with gum probing and X-rays even without symptoms.[7]
Known factors that raise the risk include a history of gum disease, smoking, uncontrolled diabetes, a prosthesis shape that is hard to clean, and a lack of regular maintenance. In a meta-analysis of more than 80,000 implants, the failure rate in smokers was about 6.4%, twice that of non-smokers (about 3.2%).[3] Conversely, peri-implant disease was less common in people who received regular maintenance, and checkups at least every 5–6 months, adjusted to risk, are suggested.[5]
An implant is a structure of three parts (body, connecting post and prosthesis) assembled with a screw, so repeated chewing force can loosen the screw or break the prosthesis. Unlike inflammation, this is closer to a “breakdown,” and it can usually be fixed without removing the implant itself. A systematic review comparing screw-retained and cement-retained prostheses (Korean) also reported mechanical complications at a certain rate with both methods, and it was hard to say that either was better in every respect.[8]
When a screw loosens, the prosthesis moves slightly and food starts to get caught in the gap. Using it this way for a long time can break the screw or damage the post, so it is best to have it checked as soon as you feel movement. Prosthesis fractures occur more often in people with tooth grinding (Korean) or clenching, at sites that take a lot of force such as the molars, and where the bite is concentrated on one point. The characteristics of each material are summarized in Types of implant crowns (Korean).
In the lower jaw there is a nerve canal responsible for sensation in the lip and chin, and above the upper molars there is an empty space called the maxillary sinus. If an implant touches or invades these structures, problems such as altered sensation or sinusitis can arise. Both are problems to be “avoided by measuring distances before surgery,” not problems to be “fixed after they occur.”
Nerve damage (Korean) in the lower jaw is rare, but once it occurs recovery can take time or some of it may remain, and case reports continue to appear.[9] The American Academy of Oral and Maxillofacial Radiology recommends cross-sectional imaging (CBCT) of the placement site when planning implants. A panoramic X-ray compresses three dimensions onto a flat image, so even if the implant site appears to overlap the nerve canal, the actual distance may be different.[10]
In the upper jaw, when bone height is insufficient, a sinus lift (Korean), which raises the floor of the maxillary sinus (Korean), may be needed as well. If the sinus membrane tears during this procedure, sinusitis or displacement of the implant into the sinus can occur, so we look at the membrane thickness and sinus condition on CT in advance.
Pooling studies that followed recent implant systems for 10 years or more, the 10-year survival rate is about 96% (95% confidence interval 95–98%).[2] However, this figure means “still in the mouth,” not “used without any problem,” and in the same study survival was somewhat lower in those aged 65 or older. Even if bone has been lost to peri-implantitis or the screw has been retightened several times, the implant counts as “surviving” as long as it remains.
That is why what determines lifespan is the care that follows more than the implant product. The finding that peri-implant disease was less common in groups receiving regular maintenance supports this.[5] More detail is in the Implant longevity (Korean) entry.
Before you decide on an implant, Joy Dental Clinic Bongcheon reviews your 3D CT together with you and checks the items below. At this stage, risk factors are identified in advance and reflected in the plan.
| Item checked | Why we look | What changes depending on the result |
|---|---|---|
| Distance to the nerve canal (lower jaw) | To avoid altered sensation | Implant length and position, choice of a short implant |
| Bone height to the sinus floor (upper jaw) | To avoid maxillary sinus problems | Whether a sinus lift is needed, and which approach |
| Bone width and density | Whether initial stability can be achieved | Whether a bone graft (Korean) is needed, healing period |
| Gum thickness | Whether the gum can resist peri-implantitis | Considering a gum graft |
| Condition of opposing and neighboring teeth | Whether force will be concentrated in one place | Prosthesis shape, bite design |
| Smoking, diabetes, medications | Failure rate and healing speed | Advice to quit smoking, blood sugar check, discussing medication adjustments |
Having diabetes does not mean you cannot have an implant. An analysis pooling 14 studies found no significant difference in failure rate between people with and without diabetes, but uncontrolled blood sugar is a separate matter, and surrounding bone loss may be greater.[4] This is why we ask about your recent HbA1c level before surgery.
One to two weeks after the prosthesis is connected, we check the bite and screw condition once more, and after that, every 3–6 months, we look at the gums, bone, screw loosening and changes in the bite. At each checkup we look at three things: whether the gum bleeds when lightly probed (the first sign of mucositis), whether bone height on the X-ray is the same as last time (a sign of peri-implantitis), and whether the prosthesis has become loose or food has started to get caught somewhere (a sign of screw or bite problems).[7]
If we see a problem, we tell you first. If it is found at the mucositis stage, it can be reversed with professional cleaning and correcting your brushing; once bone loss has begun, treatment becomes more complicated. A loose screw just needs retightening, but if it keeps happening, the cause must be found. At home, the most important thing is cleaning the neck of the implant with an interdental brush; for details, see Peri-implantitis (Korean) and Eating after treatment (Korean).
Health insurance implants require being 65 or older, partially edentulous (cases with no teeth at all are excluded), two per lifetime, and a 30% co-payment.[11] Even for a covered implant, retightening screws, repairing the prosthesis or remaking it after the prosthesis is fitted are non-covered, and the cost is explained at the consultation.
The cost of repair or retreatment for a non-covered implant depends on the type of problem (screw replacement, remaking the prosthesis, peri-implantitis treatment, re-placement) and its extent, and is explained at the consultation after diagnosis. For implants done at Joy Dental Clinic Bongcheon, checks and simple adjustments are carried out as part of regular checkups. This varies individually and is explained after a detailed diagnosis and consultation.
In the following cases, we postpone the implant or consider other approaches first.
There are also cases where treatment is not needed. If a single last molar is missing and there is no opposing tooth, or you have no difficulty chewing, it does not necessarily have to be filled. The criteria for this judgment are in our Overtreatment and undertreatment guide.
If peri-implantitis develops, does the implant have to come out? No. In the early stage with little bone loss, progression can be stopped with cleaning, disinfection and correcting your brushing. If a lot of bone has been lost and the implant is loose, or the inflammation keeps returning, removal followed by re-placement is considered.[7]
My gum bleeds but it doesn’t hurt. Is that okay? It may not be. Painless bleeding is the most common first sign of peri-implant mucositis. If it is caught at this stage it can be reversed, so do not put it off; have it checked.
What happens if a screw loosens? The prosthesis is opened and the screw is retightened to the specified torque. It usually takes just one visit, but if the same screw keeps loosening, we look again at the bite and the fit of the post.
My implant prosthesis broke. Does it have to be remade? It depends on the extent of the break. If only a little of the outer porcelain has chipped off, it is smoothed or repaired; if the metal or zirconia body itself is broken, the prosthesis is remade. In most cases the implant body itself continues to be used.
My lower lip keeps feeling numb. Will it come back? Numbness for a few hours right after surgery may be due to the anesthesia. However, if altered sensation of the lower lip or chin remains after the anesthesia should have worn off, do not wait; contact the clinic that performed the surgery right away. It is reported that the sooner nerve damage is assessed, the better the chance of recovery, and we do not recommend watching it for several days.[9]
After an upper-jaw implant, I have nasal discharge mixed with blood. This can be common for a few days after a sinus lift. If it continues for more than a week, or there is facial pressure or a foul smell, it may be sinus inflammation and needs to be examined. During that time, do not blow your nose hard.
My implant is loose. Does that mean it has failed? A loose prosthesis only (screw loosening) and a loose implant body (osseointegration failure) are different. They can look the same, so they must be distinguished in the clinic. If the body is loose, it needs to be removed.
I smoke. Can I get an implant? You can, but you should decide knowing that the failure rate is about twice that of non-smokers.[3] We recommend quitting for at least a few weeks around the time of surgery.
Is it not possible if I have diabetes? An analysis found no significant difference in failure rate when blood sugar is controlled.[4] If it is not controlled, healing is slower and the risk of peri-implantitis is higher, so getting blood sugar under control comes first.
I’m getting osteoporosis injections. Depending on the type of medication and how long you have used it, there is a risk of jawbone necrosis, so it needs to be discussed with the clinic that prescribed it. Please tell us the names of the medications you take at the consultation.
Can implants catch gum disease too? If your remaining natural teeth have gum disease, the same bacteria can spread to the area around the implant. That is why gum disease is treated first.
How often should I have checkups? Peri-implant disease was less common in groups receiving regular maintenance, and an interval of at least every 5–6 months, adjusted to risk, is suggested.[5] If you have a history of gum disease or smoke, we set it shorter.
I was told the bone around my implant has been lost. Can the implant be saved? It depends on the extent of the loss. Regenerative treatment, which cleans the surface and adds a bone graft, can be attempted, but the outcome cannot be guaranteed, and depending on the condition, removal may be the better choice.
Is re-placement harder than the first time? The bone at the site where the implant was removed shrinks, so a bone graft may be needed and the healing period may be longer. We first find the cause of the first implant’s failure so the same thing does not happen again.
Is food getting caught around an implant also a side effect? There are several causes, such as the prosthesis shape, movement of neighboring teeth and screw loosening. The problem is not so much the food getting caught as inflammation developing at that site, so we find the cause and adjust. More details are in Food getting caught around implants (Korean).
Will an implant last a lifetime? There is a figure of about 96% 10-year survival, but no data promises a lifetime.[2] It is accurate to understand that it depends on care.
This guide was written and reviewed by Director Jeong Jinwoo of Joy Dental Clinic Bongcheon (board-certified prosthodontist and specialist in integrated dentistry) based on standard dental knowledge. At Joy Dental Clinic Bongcheon, the director personally handles everything from diagnosis and treatment to regular maintenance afterward. We are right next to Exit 1 of Bongcheon Station on Line 2, and directions from Seoul Nat’l Univ., Sillim, Nakseongdae and Sadang Stations are in Directions.
This article is for general information and does not replace a diagnosis or treatment plan for your individual condition. The risks of side effects and how they are handled differ individually and are explained after a detailed diagnosis and consultation.
RESERVATION
This article provides general information. An accurate diagnosis and treatment plan are given through consultation.
33 m from Exit 1, Bongcheon Station (Line 2) · Directions from Bongcheon Station →
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