1 Volume 23 2024 e249184 Original article Braz J Oral Sci. 2024;23:e249184http://dx.doi.org/10.20396/bjos.v23i00.8669184 1 Department of Dentistry, Federal University of Juiz de Fora, Governador Valadares, MG, Brazil. Corresponding author: Jean Soares Miranda Department of Dentistry, Federal University of Juiz de Fora, Campus Governador Valadares. R. São Paulo, 745, Centro, Governador Valadares Minas Gerais, Brazil Phone: +55333301-1000 E-mail address: jean.miranda@ufjf.br Editor: Altair A. Del Bel Cury Received: May 06, 2022 Accepted: July 14, 2023 Recommendations for post-rehabilitation care of maxillofacial prostheses Leiliane de Oliveira Costa1 , Sabrina Gomes Martins Soares1, Brenda Neves Barreto1 , Filipe Costa Almeida1 , Alexa Magalhães Dias1 , Jean Soares Miranda1* Aim: This study aimed to review the scientific literature to describe the main care and hygiene protocols for different types of maxillofacial prostheses (MFP). Methods: A bibliographic search on the PubMed / Medline database using the following keywords: [“maxillofacial prosthesis” OR “ocular prostheses” OR “palatal obturators”] AND [“Cleaning” OR “disinfection”] AND [“care”] AND [“color stability”] OR [“denture cleansers” OR “cleansing agents”]. Articles addressing materials, cleaning and disinfection protocols, and care related to MFP were included. The following exclusion criteria were applied: no adequate methodology, incompatibility with the area of interest, and unavailability for reading in full. Results: The papers were grouped into the following topics: facial prostheses, ocular prostheses, maxillofacial intraoral prostheses, and retention systems. Conclusion: Despite the MFP changes over time, its degradation decreases upon following the recommendations and post-adaptation care. The guidelines for cleaning and disinfection must be individualized to guarantee the longevity of the prosthesis and the patient health. Keywords: Maxillofacial prosthesis. Maxillofacial prosthesis implantation. Palatal obturators. Ossicular prosthesis. Disinfection. https://orcid.org/0000-0002-6680-9836 https://orcid.org/0000-0002-7158-1856 https://orcid.org/0000-0002-5966-5061 https://orcid.org/0000-0002-3351-6586 https://orcid.org/0000-0001-5379-0155 2 Costa et al. Braz J Oral Sci. 2024;23:e249184 Introduction Maxillofacial prosthetic treatment is aimed at the rehabilitation of acquired or con- genital mutilation to restore aesthetics, protect remaining tissues, and assist in psy- chological therapy1-3. Studies have reported that reconstructing intraoral (mandibular, maxillary, or palate defects) or extraoral anatomical structures (eyes, nose, ear, and facial structures) is accessible, inexpensive, non-invasive, and strongly influences the patient’s quality of life and self-esteem2-5. Maxillofacial prostheses (MFP) can be manufactured using alloplastic materials such as polymethylmethacrylate (acrylic resin or PMMA), polyurethanes, latex, and silicone or vinyl plastic polymers. These prostheses can have different retention means, such as the anatomical defect itself, remaining teeth, osseointegrated implants, adhesives, and eyeglasses4. The care involved in the methods of disinfection, placement, and removal of the prosthesis is crucial for its durability and the health of the surrounding tissues6. Thus, the post-installation recommendations of MFP should be considered during the prosthetic planning, when the material, retention system, and clinical approach most suitable for the patient will be determined7. Therefore, the guidelines on care and hygiene should be individualized and the patients must be monitored to ensure that they are cleaning their prostheses correctly, also in addition to solving their doubts2. However, disinfection protocols may not be always effective and can change the prop- erties of the polymers used to fabricate MFP8. In contrast, there is still no consensus in the literature regarding the best hygiene and care methods for each material, type of MFP, and retention system. Aiming to enlarge the knowledge on prosthetists concern- ing the guidelines for patients, this study reviewed the literature on post-installation care for MFP by systematizing the recommendations according to the variables and characteristics of the different types of prostheses. Methods We conducted a literature search on the PubMed/Medline database using the fol- lowing keywords: [“maxillofacial prosthesis” OR “ocular prostheses” OR “palatal obturators”] AND [“Cleaning” OR “disinfection”] AND [“care”] AND [“color stability”] OR [“denture cleansers” OR “cleansing agents”]. Articles that discussed materials, cleaning and disinfection protocols, and care related to MFP were included. The search was widened, when necessary, and references cited in the publications were also included. Neither the year of publication nor the language of articles were delimited. After rewewing the articles, we included as all papers that showed to be sutitable to our central theme. Relevant concepts and the publication of well-known and trusted journals were considered as important requirements. We disregarded any articles that presented no adequate methodology or did not address the area of interest, in addition to those that were not available for reading in full. 3 Costa et al. Braz J Oral Sci. 2024;23:e249184 Literature Review This review presents the mostly recommended hygiene and care methods for each type of MFP considering the material of manufacturing and retention system used. The recommendations were divided by a) classification of the MFP variables and the characteristics of the different types of manufacturing materials and b) retention sys- tems. Table 1 summarizes the main care and hygiene methods. Table 1. Main Recommendations for Post-adaption Care of Maxillofacial Prostheses Facial Prostheses (FP) • Whenever possible, remove the prosthesis before sleeping25. • Cleaning can be done through mechanical removal with water and neutral soap, without rubbing8. • Daily immersion in 0.2% CHX for 5 min is also indicated2,25. Ocular Prostheses (OP) • Regular replacement of the artificial eye is indicated28. • For adult individuals, the prosthesis must be changed every two or six years, depending on age, care with the prosthesis, and constituent materials27,29. In the age group from 10 to 12 years old, it must be renewed every six months28,30,70. For younger children, replacement should be quarterly31. • Control consultations should be annual for adults and semiannual or quarterly for children31. • Daily use of lubricant eye drops is recommended31,32. • Morning irrigation of the eyelids with saline solution to remove crusts, secretions, or debris from the anophthalmic socket34. • The prosthesis must be professionally polished once a year to remove irregularities and maintain its surface gloss28,32. • The acrylic resin OP must not be cleaned with alcohol, abrasives, or aggressive chemicals27,35. The use of common soap or products containing colorings should also be avoided26. • Daily cleaning of the prosthesis can be performed with 0.5% CHX or Efferdent. • For periodical cleaning (every three days), an alkaline peroxide tablet or 4% CHX can be used38. • Do not clean less than monthly or more than semiannually28. • Do not remove the prosthesis before sleeping9,30,36. Maxxilofacial Intraoral Prostheses Pre-installation care: • The dentist must immerse the acrylic in an anionic detergent solution (without flavoring) for 20 min; wash in filtered water; then immerse it in hydrogen peroxide for 10 min and finally wash with sterile distilled water or saline solution. Disinfection before installation can also be performed by immersing the prosthesis into a 0.5% povidone-iodine solution, followed by immersion in saline solution for 20 s.47. Daily care: • The patient should be instructed to brush the denture with water, neutral soap, and a toothbrush with soft bristles after each meal when waking up, and before bedtime2. • Tubes of toothpaste containing abrasive agents and mouthwashes are not indicated for cleaning the prosthesis48. • The prosthesis should never be boiled2. • For tissues, CHX is the most recommended antiseptic. • For maxillectomized patients, irrigation with saline solution (or salt and sodium bicarbonate) through the nasal cavity is indicated, as well as oral washing several times a day43. Continue 4 Costa et al. Braz J Oral Sci. 2024;23:e249184 Continuation Chemical retention by adhesives • It is essential to remove the prosthesis to sanitize it and the remaining tissues for purposes of preservation57. • Consider using adhesive removers during the prosthesis removal process71. • Mineral oil or Vaseline can also be used in situations where the adhesive will not be reapplied in the same area within a short period66. • The surface of the prosthesis and the skin must always be clean and dry before using the adhesive71. • It is advised to use an alcohol-free skin barrier for skin protection before applying the adhesive71, which should only be applied on dry skin66. • Reapplying the adhesive layer is indicated every 4 or 8 h.62. • Using more than one layer of adhesive increases bond strength47,49. • In cases of allergy and/or irritation caused by the use of adhesives, the wound must be cleaned with a non-toxic solution. For contact dermatitis, apply cold compresses over the region and use lipid-containing moisturizers. Topical steroids are also indicated to control inflammation. If the lesion does not regress within 7 days, a dermatologist should be consulted66. Implant retention system • Remove the prosthesis before bedtime25. • Isopropyl alcohol can be used to remove oily residue from the restorative material and skin2. • Cleaning the areas around the abutments daily and preferably at night58. • Cleaning the abutments: moisten the area and any dry residue present with a mixture of water and hydrogen peroxide (50:50) or water and neutral soap. Then, use a cotton swab or soft brush to carefully clean the area around the skin, the abutment, and/or the bar, avoiding traumatizing the tissues26. Facial Prostheses (FP) Nasal, lip, oculopalpebral, and auricular4,7 prostheses are made for large facial defects. Polydimethylsiloxane (silicone) and PMMA are the most commonly used materials for manufacturing FP9. Acrylic resin is occasionally used when there is small tissue movement during function10 and it can also be composed of an infrastructure coated by silicone7. Silicone is the material of choice for manufacturing since its flexibility provides patient comfort and a texture like the human skin8. The mean useful life of the silicone-based FP ranges from 1.5 and three years, but only 4.8% of them last more than 2 years7,11-13 since it is difficult to repair and its aes- thetic and physical properties are compromised when exposed to solar radiation, changes in temperature, humidity, body secretions, and disinfecting agents. Such a scenario results in discoloration, misfits, and degradation, thus requiring continuous maintenance appointments2,7,14,15. Prostheses are exposed to environmental conditions and the user’s skin. In general, acidic and alkaline perspirations are absorbed by silicone affecting its elasticity and hardness and contributing to polymer degradation. Contact with the skin allows micro- organisms to grow, such as fungi and bacteria from the skin’s natural microbiota. The porosity and roughness of silicone also allow biofilms to form, which are resistant to removal and can cause irritation and infection on the patient’s skin, in addition to the presence of black spots and unpleasant odor7,8,16. Sebum can also interact with the silicone surface, causing some change in color17-19. 5 Costa et al. Braz J Oral Sci. 2024;23:e249184 In this context, care with the prostheses before its installation is also necessary. They must be sterilized in humid heat at 120°C for 1 hour2. The frequent cleanness of the FP is essential for its longevity and preserving the patient’s health. However, cleaning products and disinfectants can also degrade silicone. Disinfection by immersion in solutions containing chemical agents, such as effervescent tablets, 1% sodium hypo- chlorite, and solution of 2% to 4% chlorhexidine gluconate (CHX) may also be indi- cated8,20-23. The negative effects of these disinfection methods on prosthetic silicones include the presence or absence of additives, such as pigments and opacifiers6,8,23. A 4%-CHX solution showed to produce a greater color change in silicone than efferves- cent tablets based on alkaline peroxide20. In addition, hand-washing the silicone with mild soap and water for 30 s has been reported to be significantly more effective in reducing biofilm (C Albicans and S aureus)8. Chamaria et al.23 reported that sanitizing maxillofacial silicones by brushing with anti- bacterial soap caused clinically unacceptable color changes; however, when cleaned with a 2%-CHX solution, there was a noticeable but acceptable color change. Addition- ally, sodium hypochlorite discolors this material, which may be maximixed by effer- vescent tablets. Thus, 0.2% CHX can be considered the most suitable agent for the disinfection of FP24. Despite the lack of an established protocol for cleaning FP, the methods of washing the maxillofacial silicone with water and neutral soap (without brushing)8 or immers- ing it in 0.2% CHX24 are considered efficient for causing less changes in the silicone properties. The immersion in CHX solutions is efficient for disinfection of both acrylic and silicone resin prostheses24,25 and should range from 2 to 5 minutes (min) daily since it starts acting in 15 seconds (s), maintaining a residual effect of 6 hours (h)2. Patients should also be instructed not to sleep using the prosthesis. Removing the FP for sleeping prevents the occurrence of trauma and the growth of microorgan- isms by the accumulation of humidity, in addition to the irritation and inflammation of surrounding tissues2,26. Ocular Prostheses Ocular prostheses (OP) provide patients with aesthetic and functional benefits by pro- tecting the anophthalmic socket from ulcers, infections, tissue retraction, and severe orbital defects27. To maintain its functions, the artificial eye must be correctly fitted to the socket and kept in an excellent state of preservation28. Over time, the anophthal- mic socket and the surrounding tissues may undergo changes, resulting in the misfits of the OP, leading to the development of tissue hyperplasia or chronic conjunctivitis. Thus, replacement of the artificial eye should be indicated29. Among adult individu- als, the OP longevity ranges from 2 to 6 years, according to patient’s age, prosthesis care, and constituent materials28. In the age group of 10 to 12 years, the OP must be replaced every six months30. For younger children, replacement should be quarterly. Thus, follow-up visits should be at least annually for adults and semiannual or quar- terly for children31. During the process of eyeball enucleation, the lacrimal glands are often preserved and can provide natural lubrication for the OP32. However, many patients experi- 6 Costa et al. Braz J Oral Sci. 2024;23:e249184 ence discomfort from dryness and irritation. Therefore, regular use of lubricant eye drops is recommended31,32. There is a variety of lubricants available, includ- ing silicone oil-based drops, artificial tears, hard contact lens wetting drops, and lubricants made specifically for OP32. Each patient suits best to a type of lubri- cant, from the morning rinsing of the eyelids to cleaning crusts and secretions to improve artificial eye tolerance, thus reducing complications28,31,33. Saline solu- tion is the most commonly used eyewash solution to remove debris from the anophthalmic socket34. The OP is frequently made of PMMA due to its low cost and easy handling, in addition to provide satisfactory adaptation and esthetics35. This material must be cleaned with alcohol, abrasive cleaners, or aggressive chemicals due to possible corrosion, cloud- ing, scratching, or roughening on the prosthesis surface28,36. In addition, OP suffers mechanical injuries and, over the years, its surface becomes more porous, promot- ing the deposition of bacteria, increased secretions, and discomfort. Therefore, they should be polished once a year to remove irregularities and preserve surface gloss28,31. In general, the OP should not be removed at night since less frequent manipulations reduce the mechanical stress on the conjunctival, preventing it from any inflamma- tion and avoiding tear fluid accumulation and mucus formation29,31,37,38. The prosthesis should never remain removed for several days in a row since it may cause the anoph- thalmic socket to retract28. In case of necessity, the artificial eye should be removed by clean hands, and the OP must not be cleaned under tap water, since it is a potential source of contamination. Also, common soaps should not be used as they often con- tain oils, coloring, or perfumes that can irritate the conjunctiva. The use of products containing preservatives should also be avoided due to the risk of inducing allergic reactions in ocular tissues28. Despite the lack of consensus on cleaning methods for OP, some cleaning agents are more often recommended, including multipurpose solutions for hard contact lenses (no peroxides or alcohol), mild soap, CHX, alkaline peroxide tablets, and baby sham- poo28,32,33,36. Paranhos et al.39 demonstrate that all these cleaning agents are effec- tive in reducing aerobic microorganisms present in the prosthesis and anophthalmic socket. However, only a multiuse solution and 0.12% CHX were able to significantly reduce the number of Staphylococcus aureus. Another recent study assessed the effect of disinfectants on Staphylococcus aureus and Staphylococcus epidermidis biofilms formed on the OP surface and found that the alkaline peroxide tablet and 0.5%, 2%, and 4% CHX significantly reduced the number of colony-forming units for both bacteria. However, neutral soap and multiuse solution were not recommended for disinfecting the PO. Instead, the authors recommended daily disinfection of the prosthesis with 0.5% CHX or Efferdent. Alkaline peroxide tablet or 4% CHX can be used for cleaning every three days36. Due to divergences in the literature, it is not possible to establish an ideal clean- ing protocol28. Problems related to mucoid discharge and discomfort appear to be reduced when patients are encouraged to not clean the OP daily29,38. In gen- eral, irritation symptoms are not related to altered bacterial flora, but excessively frequent cleaning regimens, as the constant manipulation of these prostheses is associated with an increase in gram-negative bacteria40. Such a habit should 7 Costa et al. Braz J Oral Sci. 2024;23:e249184 be avoided since the increase in pathogenic flora, especially Gram-negative bac- teria, is related to the discomfort felt by users of OP41. In contrast, patients who do not clean the artificial eye daily have more pathogens and are more suscepti- ble to infections42. Thus, Pine et al.38 suggested that patients clean their prosthe- sis according to their own needs but advise that prosthetic eyes should not be cleaned less than monthly or more than semiannually. To guarantee the maintenance and longevity of the OP, there must be a close col- laboration between ophthalmologists and ocularists to define customized care and cleaning methods to meet the needs of each patient33. Maxillofacial Intraoral Prostheses There are several types of intraoral prostheses (IP), highlighting the palatal prostheses for cleft patients and obturators (immediate, interim, and definitive)43. Palatal prosthe- ses isolate the nasal cavity and the maxillary sinus from the oral cavity and its fluids, food, and external environment. In addition, they contribute to the improvement of phonation and swallowing44. Immediate prostheses are used after surgical maxillec- tomy to separate the nasal cavity from the oral cavity, assist in healing, and allow for intelligible speech in the immediate postoperative period43,45. The interim obturator prosthesis is installed after the early healing period and is used in a decisive phase for therapeutic success until the healing is complete43. Edentulous obturators consist of PMMA while partially edentulous obturators are supported by chrome-cobalt (CoCr) alloy frameworks43. The prostheses of the obtu- rators must be cleaned before being installed in the patient. They can be washed with water and neutral soap and immersed in an anionic detergent solution (unscented) for 20 min. Subsequently, these prostheses should be washed under filtered water and immersed in 10 volumes of hydrogen peroxide for 10 min, and finally washed under distilled water or saline solution (both sterile)2. It is also possible to decontaminate the obturators before installing by immersing them in 0.5% povidone-iodine solution and saline solution for 20s46. Once installed, these prostheses can become reservoirs or deposits for the devel- opment of bacteria since correct prosthetic hygiene and the remaining tissues are important for the longevity of the prosthesis and the maintenance of oral health. It is recommended to brush the denture with mild soap and soft-bristled brushes. For disinfection, the prosthesis can be sprayed with 4% CHX for 1 min and then washed under running water2. Therefore, the daily hygiene of removable dentures should include both brushing and immersion in disinfectant solutions for less than 10 min47. Cleansing regimens must be able to remove stains and bacterial plaque without damaging the properties of the material and its surface48. Commercially available denture cleansers use various active agents to remove biofilm from dentures, includ- ing alkaline peroxide, sodium hypochlorite, and oral mouth rinses47. Felipucci et al.49 showed that chemical agents such as Periogard (0.12% CHX), Cepacol (Cetylpyri- dinium chloride 0.500 mg), and effervescent tablets (sodium perborate-based, like Corega Tabs, and Polident) proved suitable for cleaning removable dentures. How- 8 Costa et al. Braz J Oral Sci. 2024;23:e249184 ever, these chemical agents should be used carefully as they may cause significant color change and alter the roughness and hardness of the resin surface50, even in denture bases reinforced with ZrO2 nanoparticles51. In contrast, effervescent tablets have demonstrated a good combination of microbial efficacy and reasonable com- patibility with the material48. Commercial toothpaste contains abrasive agents and are not suitable for cleaning dentures. Likewise, alcohol-based mouthwashes and isopropyl alcohol are not recom- mended for cleaning the prosthetic base made of PMMA for promoting considerable changes such as increased roughness and decreased shine. Obturator prostheses with metallic frameworks require careful selection of chemical cleaning agents as they are usually manufactured with CoCr alloys. When contacting the chloride or oxygen present in some cleaning products, these alloys can suffer corrosion or staining48,52,53. The 0.05% sodium hypochlorite and tablets citric acid-based promote no significant changes in the roughness of CoCr or on the surface of thermal polymerization res- ins. However, they stain and corrode the metallic components of the removable par- tial dentures, thus being not indicated to clean these prostheses49. In addition, 0.05% sodium hypochlorite can cause dark spots on the metallic surface of the Ni-Cr-Mo-Ti and Ni-Cr-Mo-Be alloys54. Other substances, such as vinegar and soap, are compatible with this alloy but do not show antimicrobial efficacy. However, peroxide-based effervescent tablets can pro- mote antimicrobial disinfection and, at the same time, cause little damage to acrylic and metal alloys48. Edentulous patients after maxillectomy suffer from speech impairment and masti- catory dysfunction. When the use of denture adhesive is necessary to improve its retention, zinc-based adhesives are contraindicated. Additionally, at each cleaning, the adhesives must be completely removed from both the prosthesis and the oral cavity47. Regular use of antiseptics, especially CHX is recommended to maintain oral tissue health55. Irrigating the nasal cavity with saline solution (or salt and sodium bicarbon- ate) is essential for maxillectomized patients, as well as oral rinses several times a day. The patient should be encouraged and instructed to maintain the excellent oral hygiene of the remaining dentition and attend periodic follow-up visits for assessing oral and denture conditions43,44,48. In case of injuries to the prosthesis, such as frac- tures, care should be sought as soon as possible2. Retention systems The MPF can be retained through surgical, anatomical, chemical, and mechanical methods56. Because the longevity of these prostheses is related to these methods, for a greater acceptability of the treatment, it is essential that the retention system is carefully chosen since it provides esthetics, function, and comfort to the patient18. Adhesive retention (chemical retention) Currently, adhesive retention is one of the most used methods for the fixation of MFP57. This system is commonly used for fixing FP considered weightless and/or smaller58. 9 Costa et al. Braz J Oral Sci. 2024;23:e249184 The adhesives must not be irritating or toxic to human tissues and not interfere with blood circulation59; in addition, it must promote adequate bond strength60 to prevent detaching of the FP from the skin interface. If such criteria are met, the patient accepts the prosthe- sis better, thus promoting a positive psychological effect and better prognosis61. Since moisture, sweat, and skin oils can reduce the retentive capacity of adhesives, they should be reapplied every 4 or 8 h62. For a greater durability, two layers of adhe- sive should be applied to increase its bond strength63. Kiat-Amnuay et al.63 recom- mended a “sandwich technic” with Secure 2 Medical Adhesive (SMA, Factor II, Lake- side, Arizona, USA) applied to the skin, and Epithane-3 adhesive (E3, Daro Products, Muskego, Wisconsin, USA) to the prosthesis. The authors found that such an appli- cation method increased the bond strength compared with the isolated use of one of these adhesives. In addition, the use of primers, such as Sofreliner T (Sofreliner Tough, Tokuyama Corp., Tokyo, Japan) and Sofreliner MS (Sofreliner MS Tokuyama Corp., Tokyo, Japan), promote a better bonding to the silicone61,64,65. Removing the prosthesis to sanitize it and the remaining tissues is essential for main- taining health57. Adhesive residues must be removed from the prosthesis to prevent them from affecting the adhesion and durability of the new adhesive layer that will be applied to the skin. Isopropyl alcohol2 and solvents such as Uni-Solve (Smith 1 Nephew, Largo, Florida, USA) can be used since they do not interfere with the adhe- sive properties57. It is suggested to use removers to remove residues from the skin to reduce the patient’s discomfort. Alternatively, the use of mineral oil or Vaseline is rec- ommended since they can contribute to loosening the adhesive tape; however, they should only be used in situations where the adhesive will not be reapplied within a short period of time66. The contact of adhesives with the skin can cause dermatological problems and make it difficult to clean them. More retentive adhesives cause greater irritation to the skin as they require greater strength to remove and daily care to maintain skin integrity57. Therefore, the use of protective dressing as Skin-Prep (isopropyl alcohol, butyl ester of polyvinyl methacrylate/methyl methacrylate copolymer, acetyl tributyl citrate - Smith & Nephew, Inc, Largo, Fla.) is indicated to reduce trauma and irritation by the adhe- sive, in addition to improving its retention in up to 6 h57. For applying this cutaneous film, the skin and the prosthesis must be clean and dry, and the film must be dry for the adhesive to be applied. Before applying the adhesive, the protective dressing film must also be dry66. The severity of the injury must be assessed in cases of allergy and/or irritation caused using adhesives. The wound must be cleaned with a non-toxic solution and an established therapy. For contact dermatitis, cold compresses should be applied to the region, as well as moisturizers containing lipids as a component. Topical steroids are also indicated to control inflammation. In the absence of regression of the lesion within 7 days, an evaluation by a dermatologist is recommended66. Mechanical retention In some situations, the prosthesis can be anchored in the anatomical defect, for example, the OP, which is retained by the orbital cavity itself58. 10 Costa et al. Braz J Oral Sci. 2024;23:e249184 When other methods are not viable, mechanical retention can also be performed by fixing the prostheses in acrylic resin frames, facilitating their use and maintenance. To minimize the weight of oculo-palpebral or nasal prostheses, eyeglasses frames are frequently used, and those with greater thickness help to disguise the edges of the prosthesis12. Implant retention system Currently, osseointegrated implants have been considered one of the best retention methods for oral and maxillofacial prostheses, and can be used for retention through magnets, bar-clip systems, or O-rings67,68. Compared with other retention methods, implants have advantages such as greater stability, support, safety, comfort, and masking of the union surface. This system is recommended for sports practice, as, unlike adhesives, its retention is not influenced by perspiration67, in addition to not causing changes in the color of the silicone, contributing to the prosthesis longevity7. However, a disadvantage of this method is the difficulty of cleaning67. It is important to clean the retainers to reduce the amount of bad waste and keep the surround- ing tissue healthy, minimizing skin irritation and contributing to better adaptation and retention of the FP. It is recommended to clean the areas around the abutments since the accumulation of debris is common in these areas, and the lack of removal can cause inflammation of the tissues69. Therefore, cleaning must be executed daily and preferably at night. A cotton swab, soft brush, or tissue soaked in a mixture of water with hydrogen peroxide or water with mild soap can be used. Another option is clean- ing using tufted dental floss with reciprocating movements. However, before flossing, the area should be well-moistened to facilitate the removal of debris26. For retention of ear prostheses with the bar-clip system, the abutments are connected to a bar, which makes the cleaning process more complex than that of the prostheses retained by independent implants26. For these cases, soft bristle brushes and neutral soap should be used in the retentive areas. Isopropyl alcohol can be used to remove oily residues from cosmetic materials and the skin; however, the patient must be very careful not to dissolve the pigments2. The most critical area to clean is around the metal pillars. In this region, it is common to find accumulations of dry residues, ker- atin, and epithelium, which, if inadequately sanitized, can lead to inflammation of the surrounding tissues. Therefore, cleaning procedures must be performed daily and preferably before bedtime. When cleaning the abutments, the first step is to moisten the area and any dry residues present with a mixture of water and hydrogen peroxide (50:50) or water and neutral soap. Then, it is indicated to use a cotton swab or soft brush to carefully clean the area around the skin, the abutment, and/or the bar, avoid- ing traumatizing the tissues26. Removal of the prosthesis during sleep is also indicated since a prolonged use can cause inadequate pressure in the retainers, in addition to irritationg and skin inflammation26. Discussion This study sought to highlight the importance of post-rehabilitation care for maxillo- facial prostheses. All recommendations must be individualized considering individual 11 Costa et al. Braz J Oral Sci. 2024;23:e249184 diseases and physical or cognitive limitations. More than 50% of the worldwide head and neck cancer cases annually diagnosed occur in patients older than 65. Thus, their additional chronic diseases could affect not only the available treatment options but also their quality of life and survival72. As oral hygiene may be compromised in elderly patients with cognitive or motoric impairment, it should be considered that measures could be performed by the patients themselves. It is crucial to secure oral hygiene and aftercare, including patient’s edu- cation and, in some cases, for caring staff or family members. Therefore, proper and regular instructions should be given and demonstrated not only for patients but also for caring relatives or caregivers (Nitschke et al.73). When the patients have their oral hygiene ability compromised, a relationship of trust in must be established in cooper- ation with caregivers for them to participate in dental prevention and therapy. In cases where patients themselves are no longer capable of making decisions, a therapeutic decision without information is both legally and ethically unacceptable. Thus, caregiv- ers and legal guardians, together with the dentist, must make decisions based on the presumed will of the patient73. Furthermore, it is worth highlighting that maintenance practices start in the prosthetic planning stage when studying the type of material to be used in the prosthesis, its retention technique, and how both relate to the type of rehabilitation recommended for the patient7. Regardless of the type of prosthesis, hygiene protocols must be rig- orously established based on the properties of the materials used for their manufac- turing. Neglecting such a step can cause microorganisms to proliferate around the prostheses and adjacent tissues. Cleaning the cavity and/or adjacent tissues is as important as sanitizing the prosthesis, especially in regions with secretion. The exis- tence of an unhealed surgical lesion also deserves special attention given the high risk of infection of the lesion2. The choice of materials is directly related to the type of prosthesis to be made. As for the MFP, different types of materials can be used for their manufacturing, including metal, silicone, or acrylic resin. However, it is noteworthy that the hygiene protocols are specific for each material (Table 1). In turn, the type of retention varies according to the location and dimension of the prosthesis57. Compared with other retention methods, implants have advantages such as greater stability, support, safety, comfort, masking off the union surface, and less chance of causing adverse effects13. Furthermore, unlike adhesives, retention is not influenced by perspiration67. However, the installation of implants must be metic- ulous and respect the correct handling of the adjacent soft tissues, bone availability, the occurrence of osseointegration, and correct implant inclination74, in addition to demanding rigorous hygiene to maintain its longevity13. Different cleaning agents have been used for cleaning maxillofacial dentures, the most common being neutral soap, CHX, isopropyl alcohol, and sodium hypochlorite. Pinheiro et al.5 reported that a 0.12%-CHX immersion showed the greatest antimi- crobial effectiveness, with results even better than mechanical brushing. However, frequent exposure to these solutions can interfere with the silicone properties8,75,76. It is essential to choose the correct solvents for cleaning the prosthesis as inade- 12 Costa et al. Braz J Oral Sci. 2024;23:e249184 quate chemical solutions can cause pigment dissolution and silicone degradation8. In a pilot study, Allen et al.77 analyzed the effectiveness of a prescribed hygiene pro- tocol for patients who received dentures retained with craniofacial implants. The authors found that damage to the silicone rubber was caused by rigorous cleaning or the use of an inappropriate cleaning agent. In general, for silicon, washing without scrubbing with water and neutral soap is recommended. Immersion in 0.2% CHX is also advised23. A correct cleaning of the prostheses requires to use mechanical and chemical methods as applying mechanical methods alone is not enough to remove microorganisms78. The surface irregularities of the prostheses favor the adhesion of microorganisms, making cleaning difficult79. Therefore, chemical substances can be used to aid in dis- infection. However, the use of abrasive products, volatile solvents, and other chemical substances that can damage prostheses must be avoided80. Regarding acrylic resin, it has been observed that CHX can be used to help remove the biofilm and clean acrylic resin dentures25. Brushing is not the most suitable cleaning method as it contributes to the discoloration of the denture by dissolving and removing pigments. In addition, when associated with abrasive products and inadequate techniques, it can lead to wear and increased roughness of the prostheses, resulting in increased accumulation of microorganisms and irritation of surrounding tissues6. Several authors do not recommend mechanical methods for sanitizing the OP since they can increase the roughness of the prosthesis, facilitating the adhesion of micro- organisms28,39,81. Moreno et al.36 assessed the effectiveness of different chemical sub- stances on the biofilm of Staphylococcus aureus and Staphylococcus epidermidis formed on the OP surface and found that 2% CHX and 0.5% CHX are clinically valid products for disinfecting these prostheses. After installation, the hygiene of the prostheses must be maintained to ensure their longevity and the health of surrounding tissues, in addition to preventing irritation and skin infections25. Therefore, it is essential to instruct the patient regarding the methods and importance of cleaning and disinfecting the prosthesis. This review addressed relevant issues concerning post-installation care for different types of MFP highlight- ing individualized care for the most used materials and retention systems. Conclusion Our results show that care with MFP should start in the planning phase and continue until installation and follow-up to reinforce to the patient the importance of cleaning the surrounding tissues and the prostheses for aesthetics preservation, health, and longevity. The dentist is responsible for informing and teaching the proper hygiene and care protocols. The material, type of rehabilitation, and retention system influence the care protocol to be established. However, the patients’ expectations should be adjusted since the expected durability of these prostheses is not always fulfilled. Conflict of interests The authors have no conflicts of interest to declare. 13 Costa et al. Braz J Oral Sci. 2024;23:e249184 Data availability Datasets related to this article will be available upon request to the corresponding author. Authors contribution Leiliane de Oliveira Costa - definition of intellectual content, literature search, manu- script preparation. Sabrina Gomes Martins Soares - definition of intellectual content, literature search, manuscript preparation. Brenda Neves Barreto - concept, literature search, manuscript preparation. Filipe Costa Almeida - concept, literature search, manuscript preparation. Alexa Magalhães Dias - concept, design, the definition of intellectual content, manu- script preparation and manuscript review. Jean Soares Miranda - design, the definition of intellectual content, literature search, manuscript preparation, manuscript editing, and manuscript review. 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