Antimicrobial Use in Implant Therapy: Is It Necessary?

Edentulism is a multifaceted condition that has become increasingly prominent. The major cause of tooth loss is periodontitis, and its mild to severe forms affect nearly 46% of the population in the United States.^1,2 Other possible etiologies include but are not limited to disease, trauma, genetic disorders, and other developmental defects.¹ Dental implants, comprised of titanium or alloplastic, inert materials, have become a popular treatment modality over the past five decades and are considered an optimal substitute for missing teeth. Implants are surgically placed and become embedded within the maxilla and/or mandible to replace missing or affected teeth.³

The use of dental implants dates back to ancient Egypt where carved stones or shells were fabricated and placed in the jaws to facilitate the replacement of missing teeth.⁴ Since then, implantology has evolved, through early civilizations, the Middle Ages, and now to more modern times. A hallmark of implant history occurred when Swedish orthopedic surgeon Dr. Per-Ingvar Brånemark was studying the concept of bone healing and regeneration. He discovered that bone had the capacity to grow in the proximity of titanium and adhere to the metal without rejection.⁴ He coined this phenomenon "osseointegration" and would continue his work and studies on animals and eventually humans, before placing the first titanium dental implant into a 34-year-old man.⁴ After years of further study and investigation by researchers and dental physicians, the US Food and Drug Administration eventually approved the use of titanium dental implants.

In clinical dentistry, four main types of implants are used: the subperiosteal form, blade form, ramus frame, and, the most used type, endosseous implants. As with any type of surgical procedure, there is risk involved in implant placement, including a wide array of postoperative complications. The most prevalent complications in implant dentistry that may eventually lead to implant failure include biomechanical overload, infection, and inflammation.⁵ About 3 million people are estimated to have dental implants, and this number is believed to increase by 500,000 each year.⁵ With infection/inflammation being a common cause of implant complications, the incidence of peri-implant mucositis has been found to comprise more than 50% of these complications and peri-implantitis more than 12%.⁵

Antibiotics have been used in implant therapy as a means of reducing the risk of implant failure. The use of antibiotics in implant dentistry, particularly prophylactic antibiotics, has been a somewhat controversial topic. Some research suggests that penicillin administered preoperatively may reduce implant failures.³ Additionally, various new technologies involving antibiotics are being developed solely for the prevention of biofilm formation on implant surfaces.⁵ Further research, however, is needed to confirm the findings of the efficacy of prophylactic antibiotic use in implant therapy, as well as to determine the most optimal way to treat the irreversible infection peri-implantitis.⁵

This article investigates the relationship of antimicrobial use and implant therapy. This includes the use of antimicrobials both prophylactically, for the prevention of complications such as implant failure, and for treatment of peri-implantitis.

Evolution of Dental Implants

In ancient times, in addition to using seashells or stones, someone looking to replace missing teeth might have received implants from the teeth of animals or carved ivory that would be secured using ligature wires often made of gold, which would help stabilize and hold the implants in place.⁶ The use of gold and/or ivory was very expensive and only available to the wealthy and likely only served the purpose of esthetics rather than function. Also, it is speculated that dental implants were often inserted post-mortem for religious reasons or esthetic purposes.⁷ Most of these early attempts at tooth replacement resulted in failure due to lack of osseointegration and the inability of the primitive dental implants to withstand high occlusal forces.⁷

In the early 20th century it was concluded that although gold was a good tooth replacement material because of its low complication rates, it was too expensive for practical use and could not properly maintain its shape.⁷ Silver was also considered because it was less expensive than gold and was able to be easily shaped and manipulated; its oxidation, however, led to the discoloration of skin, which made it undesirable as a tooth replacement alternative.⁷

In the 1930s, two brothers named Alvin and Moses Stock studied a material known as vitallium, which was typically used for hip bone implants. With a cobalt-chromium-molybdenum alloy, this was the very first biocompatible dental implant-an endosteal implant that was placed successfully in the jawbone.⁷ The first subperiosteal implant was placed in 1940 by Dr. Gustav Dahl, who implemented flat abutments and screws.⁷

Eventually, Dr. Brånemark made his accidental observation while experimenting on rabbits involving the placement of implant chambers in their femurs.⁸ He noticed that he was unable to remove the titanium from the animals because the metal was completely embedded and had integrated into the bone. In the 1960s, he designed titanium screws that he implanted into the jawbones of dogs; his findings were that the screws completely integrated into the bone.⁷ Finally, his first human experiment was performed on a volunteer with congenitally missing teeth and a skeletal malformation of the chin. In 1965, the patient received four titanium dental implants, and after a period of 6 months the implants had undergone osseointegration into the jawbone. The implants successfully remained even some 40 years later until the recipient's death.⁷

Following Dr. Brånemark's discovery and the concept of osseointegration, new types of implants and implant designs began to emerge, such as implants with a hydroxyapatite coating and those with a titanium surface spray to better optimize osseointegration, and many more.⁷ Today, after much scientific and medical progress, dental implantology is one of the primary treatment modalities for the replacement of missing teeth.

Surgical Placement of Dental Implants

The surgical placement of a dental implant is generally performed in two stages using local anaesthesia.¹ In the first stage, the gingiva and periosteum are reflected and the site undergoing the osteotomy is drilled in a predetermined location in preparation for the implant placement. A fixture made of titanium, ie, the implant, is screwed/torqued into the desired osteotomy within the jaw.¹ Implant designs vary in size, shape, surface treatment, and surface roughness. Depending on the specific case, the implant is placed and a healing abutment is screwed onto it or a cover screw is placed for the healing/osseointegration period.^1,9 When using a cover screw, the soft tissue is sutured over it and reopened after a 3- to 6-month healing period, allowing for primary closure. Conversely, with healing abutments, healing is achieved by secondary intention, and the abutment remains visible in the oral cavity extending above the mucosal surface.¹

When healing is complete and the implant has undergone osseointegration, which may take between 6 weeks and 6 months depending on the clinical scenario, the second stage of implant surgery can be undertaken. This entails removal of the healing abutment and either placement of a final stock abutment or utilization of impression abutments for fabrication of a custom abutment or other prosthetics by a laboratory.

The timing of implant placement post-tooth extraction varies and typically is broken down into four different types of classification. As shown in Figure 1, implant placement may be done immediately following extraction, 4 to 8 weeks after extraction, 12 to 16 weeks after extraction, or 6 or more months after extraction.¹⁰ These designations are classified as types I through IV, respectively, and each has different selection criteria and indications as to when they should be performed.

Type I, immediate placement, requires that there be intact facial bone wall with a thick wall phenotype, a thick soft-tissue biotype, no acute infection, and sufficient bone volume. Although a torque value of 35 Ncm is often cited as a safe threshold, the minimum insertion torque for immediate type I implant placement is still debated. For example, a recent systematic review by Hamilton et al concluded from various studies that some protocols recommend the minimum torque to be 35 Ncm or more, while a systematic review by Darriba et al displayed findings that low insertion torques of values less than 35 Ncm did not significantly affect survival rates of immediate implant loading over a mean of 24 months.^11,12 Type II, placement 4 to 8 weeks post-extraction, may be performed if there is thin or damaged facial bone wall and sufficient bone volume apically. According to the International Team for Implantology, guidelines state that when immediate implant placement is not ideal, conventional loading protocols are recommended, which would include insertion torque from 25 Ncm to 40 Ncm.^12,13 Type III is placement 12 to 16 weeks after extraction and is recommended if a large periapical bone lesion exists; however, this implant placement requires bone augmentation and guided bone regeneration. With respect to mandibular versus maxillary bone, mandibular bone is typically characterized by higher density, while maxillary bone is less dense; therefore, due to differences in healing periods, implants may be loaded at 3 to 4 months and 6 to 8 months, respectively.¹⁴ Finally, type IV is late implant placement, occurring at least 6 months post-extraction and is used only when necessary. Selection criteria include adolescent patients too young for implant therapy (typically <20 years of age), extended bone lesions apical to the root, and an ankylosed root in apical position without bone volume apical to the root.¹⁰

Indications/Contraindications for Dental Implant Placement

Many different clinical scenarios present in which dental implant placement may be indicated, as edentulism could be due to a variety of conditions, including periodontitis, caries, trauma, or maxillofacial deformities. Being a surgical procedure, implant placement has risks. Patient selection, therefore, is a critical criterion to avoid potential complications after implant placement.

Contraindications for dental implants due to systemic conditions and treatment can be categorized as relative and absolute. Recommended relative contraindications for dental implant placement include but are not limited to: children and adolescents; epileptic patients; patients with severe bleeding tendencies; patients with endocarditis risk, osteoradionecrosis risk, and myocardial infarction risk; smoking; osteoporosis; and human immunodeficiency virus (HIV).¹⁵ Suggested absolute contraindications include recent myocardial infarction/cerebrovascular accident, severe bleeding issues, active treatment of malignancy, psychiatric illness, and bisphosphonate use, although minimal evidence supports these claims.¹⁵

Patients must ensure optimal maintenance therapy, and oral hygiene must be more than adequate to facilitate longevity of the implant and minimize risk. With the clinician carefully performing a cost-benefit analysis of implant therapy with proper informed consent, and by the patient reducing risk factors such as engaging in smoking and drinking alcohol, patients can experience good quality of life reaping the functional and esthetic benefits of dental implants.

Dental Implant Complications

As the demand for dental implants increases, as it has in recent decades, the amount of complications similarly is likely to rise. Complications can occur before, during, and/or after implant treatment. Implants may be subject to either mechanical or biological complications and then described as failing or failed. A failing implant demonstrates supporting bone loss but remains immobile clinically, whereas a failed implant is clinically mobile and removal is highly recommended.³

Mechanical Complications

Mechanical complications of implants typically occur because of adverse occlusal forces functionally or parafunctionally.¹⁶ Screw loosening and related complications have been shown to have a high incidence of occurrence primarily because of factors involving the stability of the screw-joint.¹⁶ Such factors include adequate preload, the fit of mating implant components, and anti-rotational characteristics of the implant-to-abutment interface.¹⁶ Aimed at preventing implant-abutment separation, the preload is the force that resists functional occlusal forces on the screw retaining the prosthesis to the implant at its connector. However, with poor anti-rotational features, when occlusal forces exceed the preload, the screws may eventually loosen. With loosening of screws, the metal may become fatigued and eventually lead to fracture of the screws, with the abutment screws of two-stage systems failing more frequently relative to the prosthetic retaining screw and abutment screw.¹⁶

In addition to screw loosening, implant fractures are common due to biomechanical overloading.¹⁷ When the supporting bone is lost and bone resorption has occurred, excessive stress is placed on the implant, which contributes to it fracturing. Clinically, it is difficult to identify if a fracture has occurred, which is why cone-beam computed tomography or other forms of radiography are used to identify a radiolucent fracture line through the implant.¹⁷

Biological Complications

The oral cavity is rich in bacteria, housing up to 700 different species of bacteria and forming an environment known as the oral microbiome.¹⁸ Biofilms within the oral cavity form on all hard and non-shedding surfaces and, therefore, colonize sites such as teeth and other artificial surfaces after pellicle formation.¹⁹ Infection is a leading cause contributing to implant failure; currently, no single causative organism is associated with implants, rather Gram-negative, motile, and anaerobic bacteria have a high association with implant failure.^3,20 If the accumulation of these microorganisms within the peri-implant sulcus persists for long periods of time, then peri-implant mucositis, peri-implantitis, and eventually implant failure may occur.³

As the groups of pathogenic microorganisms accumulate, biological complications arise and worsen, leading to inflammation of the soft tissue and bone that surrounds the implant. Peri-implant mucositis and peri-implantitis are the most common conditions that arise from biological complications.²¹ The American Academy of Periodontology has defined peri-implant mucositis as a "disease that includes inflammation of the soft tissues surrounding a dental implant without additional bone loss after the initial bone remodeling that may occur during healing following the surgical placement of the implant."²² While different clinical and diagnostic criteria for peri-implant mucositis exist in the literature, case definitions for its diagnosis must involve the following: visual inspection demonstrating the presence of peri-implant signs of inflammation, presence of bleeding and/or suppuration on probing, an increase in probing depths compared to baseline, and absence of bone loss beyond crestal bone level changes resulting from the initial remodeling.²² Similar to gingivitis, peri-implant mucositis does not cause permanent damage and may be reversed if the bacterial biofilm around the implant is reduced.

Peri-implantitis is defined as inflammation of the mucosa and tissue surrounding the dental implant with gradual loss of supporting bone around the implant.²¹ Consensus typically has been that bone loss around implants of ≥2 mm meets the condition of peri-implantitis.²³ General requirements and case definitions for peri-implantitis include: visual inflammatory lesions in the peri-implant soft tissues along with bleeding or suppuration on probing, increased pocket depths on probing, progressive bone loss in relation to the radiographic bone level assessment at 1 year following implant delivery, and, in the absence of initial radiographic and clinical assessment such as probing depths, radiographic bone loss of ≥3 mm and/or probing depths of ≥6 mm with profuse bleeding.²¹ As shown in Figure 2, significant bone loss is evident radiographically, and this in conjunction with the clinical signs as mentioned above may constitute the diagnosis of peri-implantitis.^21,24

Implants and Antimicrobial Use

Because mechanical and biological complications can lead to bone loss, inflammation, and/or implant failure, it is incumbent that upon placement, the implant achieves adequate osseointegration and a certain level of resistance to bacterial colonization.²⁵ To improve implant duration and reduce the risk of infection, experiments have been done on implant surfaces to study how to both improve osseointegration and prevent bacterial accumulation and biofilm formation around the implant.²⁶ One hypothesis was for implants to be surface-coated with antimicrobial properties to help reduce and prevent infection.²⁶ Silver, copper, zinc, chlorhexidine, and other antibiotics seemed promising as it was presumed that these coatings would help prevent the colonization of bacteria. However, maximizing antimicrobial properties on the implant surface may in turn impede the biocompatibility and osseointegration properties of the implant.²⁶ Striking a balance between antimicrobial and biocompatible properties is key for ideal longevity of the implant.

A broad range of coatings are used with implant surfaces and differ based on various properties (Table 1). Common bacteriostatic materials include polymer coatings such as polyethylene glycol, totarol, and biosurfactants.²⁶ Bacteriostatic materials do not kill bacteria, rather they repel the bacteria from the implant surface.²⁶ The most used bactericidal materials are antimicrobial peptides, ion-implanted surfaces, photoactivatable bioactive titanium, nanomaterials, antibiotic coatings, silane, nitride coatings, and chlorhexidine coatings.²⁶

Bacteriostatic Coating Materials

Polyethylene glycol coating has antifouling properties that apply to primarily titanium surfaces.^26,27 This coating has strong bacteriostatic characteristics due to its hydrophilic and flexible nature; however, these antibacterial properties come at a cost, which is compromised osseointegration and biocompatibility properties.²⁶

Totarol is another bacteriostatic agent that aids in the prevention of biofilm formation. Its use as a coating surface on titanium implants has shown great promise in its antibacterial effect against methicillin-resistant Staphylococcus aureus.²⁸ Totarol is advantageous for its long-lasting antibacterial properties, and it shows favorable qualities for the prevention of peri-implantitis during the healing stages.²⁸

The most recent addition to the array of bacteriostatic coatings for implant surfaces is biosurfactants. Tambone et al studied the use of rhamnolipids on titanium surfaces.²⁹ Having very low cytotoxicity, rhamnolipids can preserve the biocompatibility of dental implants and prevent microbial adhesion.²⁹ When rhamnolipid solution was used to study its effects on S aureusand Staphylococcus epidermidis, after 24 hours S aureus inhibition was at 90% and S epidermidis inhibition was between 62% to 78%, making this another promising coating for the reduction of microbial anchorage.²⁴

Bactericidal Coating Materials

Strategies used to lower bacterial load count and bacterial adhesion include the use of bactericidal materials that kill and remove the pathogenic bacteria and prevent biofilm formation. Antimicrobial peptides are utilized in a solution for use on titanium implants. These peptides have strong antimicrobial properties against the Porphyromonas gingivalis species and greatly inhibit its growth in the first 12 hours after implant placement.³⁰ Although positive results have been shown for antimicrobial peptides, they are costly and highly complex to produce.

Ion-implanted surfaces incorporate the ions fluorine, copper, zinc, chlorine, iodine, selenium, and cerium in coatings for implants. Calcium-phosphate coating is commonly used on implant surfaces because of its bioactive and osteoconductive properties.³¹ This coating has been modified with the addition of fluoride and zinc ions because of fluoride's bactericidal properties and zinc's ability to enhance osseointegration.³¹ Against P gingivalis, it was shown to have strong inhibition with an 88% reduction compared to uncoated disks in the first 72 hours.

Titanium dioxide is another coating that has nanocomposite and antibacterial properties upon activation. When this material is exposed to ultraviolet light, reactive oxygen species (ROS) are produced, which then initiates its bactericidal effects against bacteria while remaining biocompatible.²⁵ Titanium dioxide coating offers biocompatibility, stability, low cost, and durability, making it a desirable coating option for dental implants. Additionally, titanium dioxide helps enhance osseointegration via promotion of cellular responses that improve bone-implant contact. Such responses may also act as reservoirs for osteoinductive agents, promoting further bone formation and osseointegration.³²

Nanomaterials or nanoparticles from silver and gold as well as from magnesium and zinc have bactericidal properties and, therefore, prevent bacterial resistance mechanisms from forming.³³ Silver nanoparticles have been shown to be efficacious as they are released over time and have demonstrated a strong and wide antibacterial spectrum.²⁶ The most plausible mechanism of action for silver nanoparticles is that the bacteria are killed from the production of ROS, which is why silver has been a much-used coating for titanium dental implants.²⁶ However, when silver is present in excess concentrations, cytotoxicity may ensue, which in turn can inhibit certain eukaryotic cells such as fibroblasts and osteoblasts and thus impede the implant's ability to undergo osseointegration.²⁷

Antibiotic coating is also used to aid in generating antimicrobial formation around implants. The three most experimented antibiotics are gentamycin, vancomycin, and minocycline.²⁶ Gentamycin is effective against both Gram-negative and Gram-positive bacteria. In one study, minimum inhibitory concentration (MIC) was achieved within the first hour, and all present Staphylococcus species were removed after the first 24 hours of coating.³⁴ In a study performed by Nichol et al, gentamycin showed exceptional results as a coating for implants, however its use was less than ideal because the release of the antibiotic was too fast for long-term prevention.³⁴ Vancomycin is used as a coating because of its broad-spectrum ability and its capacity to cover methicillin-resistant S epidermidis and methicillin-resistant S aureus.³⁵ It demonstrated promising results in a study by Zhang et al, but although no cytotoxicity was shown, its long-term effects are still in question.³⁵ Finally, minocycline is another broad-spectrum antibiotic that has been studied. It is often used in conjunction with mechanical debridement for the treatment of both periodontitis and peri-implantitis. In testing performed by Lv et al, results showed an initial burst of minocycline within the first 24 hours that fought the colonization of bacteria and stabilized during the first 7 days.³⁶ Seven days after minocycline use, no bacterial cells could be found on the titanium surface.³⁶

Of 33 articles that studied the effects of antibiotic coatings, 11 studies used gentamycin, 11 used vancomycin, and other antibiotics were used in three studies or less.²⁶ Gentamycin and vancomycin are not typically considered gold standard antibiotics for treating oral infections, which was a limitation of the studies performed. Studies in the future should investigate the use of amoxicillin or metronidazole.²⁶ Additionally, an important limitation in these studies was that they were performed outside the oral cavity and did not mimic the appropriate environment; therefore, further studies are needed to assess the effects of antibiotic coatings on dental implants.²⁶

Silane, or more specifically silane triethoxysilylpropyl succinic anhydride (TESPSA), is another bactericidal coating material commonly used due to its osteoinductive and antibacterial properties. An in vitro study by Buxadera-Palomero et al using Streptococcus sanguinis and Lactobacillus salivaris cultures found no signs of cytotoxicity present and a significant reduction in bacterial formation after an incubation period of 4 weeks compared to disks that were uncoated.³⁷ The authors concluded that TESPSA has high potential for dental applications because of its antibacterial effect after 4 weeks.

Titanium nitride coatings showed great reductions in P gingivalis cultures as well as strong potential in maintaining biocompatibility when exposed to high temperatures and corrosion.³⁸ However, another study by Ji et al showed different results in which no antibacterial activity was present against P gingivalis when titanium nitride was used.³⁹ Therefore, due to the differences between results, more studies are needed to determine the true extent of titanium nitride's antimicrobial activity.

Finally, similar to minocycline, chlorhexidine has been used in conjunction with mechanical debridement to help treat peri-implantitis. Chlorhexidine-coated implants showed promising results after 24 hours of incubation with S aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans.⁴⁰ Although commonly used for its antimicrobial properties, chlorhexidine will typically inhibit fibroblast proliferation and collagen production in a dose-dependent manner, thereby impairing and hindering wound healing. It is important that clinicians be cognizant of concentration and dosage when it comes to chlorhexidine application in order to carefully maintain a balance between antimicrobial properties and healing.⁴¹

Bacteriostatic and bactericidal coatings for dental implants have shown promising results due to their duration and antimicrobial effect. Implant placements have been shown to have higher success rates when patients are administered antibiotic prophylaxis; however, this approach is only a short-term resolution as it helps mitigate early bacterial colonization.²⁶ Nonetheless, when antibiotics are used to coat implant surfaces, they have shown to demonstrate a long-term solution for biofilm prevention, with antimicrobial coatings able to maintain effectiveness for periods ranging from a few weeks to months, with the antibacterial properties of certain coatings lasting 12 weeks.⁴² Although beneficial to some degree, this tactic comes with drawbacks, most notably antibiotic resistance.²⁶

Prophylactic Antibiotics

Many practitioners have questioned the need for antibiotic prophylaxis for implant surgery, yet one reason why antibiotics continue to be prescribed is fear of litigation and malpractice.⁴³ Many conclusions that have been made regarding antibiotic prophylaxis have come from retrospective analyses, and although it is commonly used, whether or not pre- and/or postoperative antibiotics lower failure rates of implant placement remains unclear.⁴⁴

A meta-analysis performed by Chrcanovic et al examined implant failure rates and the efficacy of prophylactic antibiotics. Of 14 studies reviewed, eight were randomized controlled trials, four were controlled clinical trials, and two were retrospective studies.⁴³ Results of the meta-analysis showed there were no significant effects of prophylactic antibiotics on the occurrence of postoperative infections in patients receiving implants.⁴³ In studies showing a low-moderate risk of bias, in the event of a postoperative infection, no statistically significant difference was shown.⁴³ Additionally, the investigation showed that in healthy patients, antibiotic usage significantly reduced early implant failure with a number needed to treat (NNT) of 50.

A few limitations and drawbacks were presented in some of the studies used in the meta-analysis.⁴³ The first was that most studies had different drug regimens, with antibiotic type, dosage, and time of administration differing among the studies. Also, in nine of the studies, patients were only followed for 3 to 6 months, thus only early failures could be assessed; future studies should have longer follow-up periods to gain a more comprehensive understanding of failure rates, which tend to increase over longer time periods. Another important variable was surgeon experience, which was evaluated alongside the use of antibiotic prophylaxis.⁴³ Surgeons with more than 50 implant placements prior to the study had greater implant survival rates when preoperative antibiotics were used.

The exact mechanism by which antibiotic prophylaxis has a significant effect on implant survival is still unknown. Newer and more thorough research is required to investigate the use versus non-use of antibiotic prophylaxis. Although significant reductions in failures were shown in the Chrcanovic et al meta-analysis, no significant effects on postoperative infections were noted when patients were given antibiotics prophylactically, and because of various confounding variables these results must be examined cautiously.⁴³

Antibiotics for the Treatment of Peri-Implantitis

Peri-implantitis has several general clinical requirements for diagnosis, including visual inflammatory lesions in the peri-implant soft tissues with bleeding or suppuration on probing, increased pocket depths on probing, and progressive bone loss as indicated by radiographic bone level assessment at 1 year following implant delivery.^21,45 Common treatment regimens for peri-implantitis include mechanical debridement, irrigation with antiseptic agents, and surgical flap access with laser therapy.^45,46 The use of local and systemic antibiotics alongside traditional peri-implantitis treatment has been increasingly investigated to determine its clinical efficacy.

In an analysis by Javed et al, 10 studies were reviewed to determine the clinical efficacy of antibiotics in the treatment of peri-implantitis.⁴⁵ Systemic antibiotics were administered to study subjects in three of the studies, and in six studies, locally delivered antibiotics were used to treat peri-implantitis. When antibiotics (both local and systemic) were used conjunctively with traditional peri-implantitis treatment, it was reported in nine of the studies that a reduction in gingival bleeding, suppuration, and peri-implant pocket depth occurred.

Various studies have used different types of antibiotics, routes of administration, dosages, and durations. In studies performed by Renvert et al and Salvi et al, local delivery of 1 mg of minocycline hydrochloride was used adjunctively with mechanical debridement and showed a reduction of inflammation.^47,48 Büchter and colleagues showed that local delivery of doxycycline was effective in treating peri-implantitis along with adjunctive treatment.⁴⁹ Additionally, Heitz-Mayfield et al reported that systemic administration of a combination of amoxicillin and metronidazole proved effective in the treatment of inflamed peri-implant tissue.⁵⁰ This evidence demonstrates that the criteria for selecting antibiotic type and dosage for the treatment of peri-implantitis remains ambiguous and the true efficacy has yet to be determined.⁴⁵

Conclusion

Since Dr. Brånemark's breakthrough study of bone growth around titanium known as osseointegration, dental implant placement has surged to become a frequent and popular treatment for patients with tooth loss worldwide. As with any surgical procedure, however, complications are possible, and in implant dentistry mechanical and biological complications are common. Antimicrobials in implant therapy have many different uses and indications. Antibacterial coatings for implants have been shown to have long-term benefits for the prevention of biofilm adhesions around implants. In contrast, the prophylactic use of antibiotics remains controversial, with literature showing that although it is beneficial in reducing implant failure, its necessity is questionable. Lastly, although the use of local and systemic antibiotics alongside traditional peri-implantitis treatment has been shown to reduce bleeding, suppuration, and peri-implant pocket depths, the criteria for antibiotic selection and their efficacy remain uncertain, and more research is needed.

About the Authors

Stefan Radovic, BSc
Fourth-Year Dental Student, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada

Aviv Ouanounou, BSc, MSc, DDS
Associate Professor, Department of Clinical Sciences, Pharmacology and Preventive Dentistry, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada; Fellow, International College of Dentists; Fellow, American College of Dentists; Fellow, International Congress of Oral Implantologists

Queries to the author regarding this course may be submitted to authorqueries@conexiant.com.

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