Extra-oral endosseous craniofacial implants: current status and future developments

Ultraviolet C as a method of disinfecting medical silicone used in facial prostheses: An in vitro study

STATEMENT OF PROBLEM

Hygiene and disinfection are important factors for preserving facial prostheses and supporting tissue health. However, a method that does not accelerate degradation or color change is necessary.

PURPOSE

The purpose of this in vitro study was to evaluate the effectiveness of irradiation with ultraviolet C light-emitting diode (UV-C LED) light in the disinfection and initial color stability of the silicone (A-588-1; Factor II) used in facial prostheses.

MATERIAL AND METHODS

One hundred and twenty specimens were made, contaminated by multispecies biofilm, and divided into 5 groups (n = 24) with different treatments: control, distilled water, 0.12% chlorhexidine, UV-C LED light, and dimethyl sulfoxide (DMSO) as the negative control. Cell viability was measured by the methyl tetrazolium salt method. Statistical analysis was performed by generalized linear models. Additional descriptive analysis was performed for color analysis by using 16 silicone specimens made with light and dark intrinsic coloring in 4 groups (controls and treatments n=4) submitted to UV-C LED light. The ΔE of the specimens was obtained by CIEDE200.

RESULTS

The results of cell viability demonstrated a statistically significant difference among the groups (P<.001), with a microbial reduction after UVC-LED exposure compared with the control group. Regarding the color, the groups presented an average ΔE (light 0.205 and dark 0.308) compatible with visually imperceptible changes (light < 0.7 and dark < 1.2).

CONCLUSIONS

Irradiation with UV-C LED light decreased the in vitro microbial cell viability of the medical silicone used in facial prostheses, demonstrating initial color stability.

Surgical preparation of nasal defects to enhance the implant-retained facial prostheses: A case report

BACKGROUND

Skin cancers requiring nasal resection may be surgically reconstructed and/or prosthetically reconstructed. Singular surgical reconstruction may be ideal for smaller defects in which the nasal bone and cartilaginous portions of the nose are maintained, but surgical reconstruction falls short of providing acceptable aesthetic results for more extensive nasal defects. Prosthetic rehabilitation, or a combination of surgical and prosthetic rehabilitation, is more appropriate for larger defects, but prosthesis retention can be challenging when adhesives are required on adjacent mobile and secreting skin.

METHODS

We report 2 cases of patients with extensive nasal defects who were successfully rehabilitated with nasal prostheses. The nasal defects were surgically optimized with immediate preparation of the surgical margins, placement of a split-thickness skin graft (STSG) within the nasal cavities and exposed maxillary sinuses, and immediate placement of osseointegrated implants.

RESULTS

Excellent prosthetic retention can be achieved without the need for adhesives. A skin graft-lined defect has minimal secretions and allows for improved defect cleansing.

CONCLUSION

The success of a nasal prosthesis depends on appropriate surgical management of the defect, and, thus, collaboration between the various surgical and prosthetic teams is essential. © 2016 Wiley Periodicals, Inc. Head Neck 39: E4-E11, 2017.

Recommendations for implant-retained nasal prostheses after ablative tumor surgery: Minimal surgical aftercare, high implant survival, and satisfied patients

BACKGROUND

Nasal defects resulting from tumor resection are preferably rehabilitated with implant-retained nasal prostheses. Aftercare, clinical outcome of the implants, and patients' satisfaction with implant-retained nasal prostheses were assessed.

METHODS

Twenty-eight consecutive patients needing total rhinectomy because of tumor resection between 1998 and 2013 were treated according to a standardized protocol with 2 implants in the nasal floor. Surgical and prosthetic aftercare was scored using patient records. Finally in 2014, skin reaction, peri-implant bone loss, and patients' satisfaction were assessed in all 13 still living patients.

RESULTS

In total, 56 implants were inserted (median follow-up, 35.1 months; interquartile range [IQR], 8.9-63.3). Implant survival was 96.4%. Implant survival was independent of radiotherapy. Peri-implant skin was healthy and patients' satisfaction high. Longevity of the prostheses was limited.

CONCLUSION

Rehabilitation of nasal defects resulting from total rhinectomy with implant-retained nasal prostheses, according to our protocol, resulted in high patient satisfaction and favorable treatment outcome. © 2015 Wiley Periodicals, Inc. Head Neck 38: E-E, 2016.

Efficacy of cleansing agents in killing microorganisms in mixed species biofilms present on silicone facial prostheses--an in vitro study

OBJECTIVES

The purpose of this study was to assess the efficacy of different cleansing agents in killing mixed species biofilms on silicone facial prostheses.

MATERIALS AND METHODS

Two bacterial and three yeast strains, isolated from silicone facial prostheses, were selected for the mixed species biofilms. A variety of agents used to clean facial prostheses were employed, viz., antibacterial soap, essential-oil-containing mouth rinse, ethanol 27 %, chlorhexidine mouth rinse, and buttermilk. Colony forming units (CFUs) and live/dead staining were analyzed to assess the efficacy of these cleansing agents against 24-h and 2-week biofilms and regrown biofilms on silicone samples.

RESULTS

Chlorhexidine was the most effective cleansing agent. Chlorhexidine killed 8 log unit CFUs (>99.99 % killing) in a 24-h biofilm and 5 log unit CFUs (>99.99 % killing) in 2-week biofilms. Also, after regrowth and repeated treatment of the biofilm, chlorhexidine was the most effective cleansing agent showing no detectable CFUs. The essential-oil-containing mouth rinse (containing 26.9 % ethanol) showed a similar efficacy as ethanol (27 %) alone. Antibacterial soap and buttermilk were the least effective agents tested.

CONCLUSIONS

Chlorhexidine showed the highest reduction in CFUs in 24-h, 2-week, and regrown mixed species biofilm of microorganisms isolated from silicone facial prostheses.

CLINICAL RELEVANCE

Chlorhexidine mouth rinse (easy obtainable and relatively cheap) is very effective in killing bacteria and yeast present in biofilms on silicone facial prostheses. When applied on a regular basis, cleansing a facial prosthesis with chlorhexidine will presumably increase its lifetime and reduce skin irritations.

In vitro antimicrobial effects of grape seed extract on peri-implantitis microflora in craniofacial implants

OBJECTIVE

To determine the antimicrobial effects of grape seed on peri-implantitis microflora.

METHODS

The grape seed extract was tested against peri-implantitis microflora most commonly found in craniofacial implants including reference strains of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Candida albicans (C. albicans) and clinical strains of S. aureus, Klebsiella pneumonia (K. pneumonia) and Candida parapsilosis (C. parapsilosis) by disk diffusion test. Minimum inhibitory concentrations (MIC) and minimum cidal concentrations (MCC) were determined using modified agar dilution millpore method. The extract was further combined with polyethylene glycol and propylene glycol, and was tested for antimicrobial effects.

RESULTS

Grape seed extract showed positive inhibitory effects with S. aureus at MIC of 0.625 mg/mL and MCC of 1.25 mg/mL respectively. However the extracts showed minimal or no reactivity against strains of E. coli, K. pneumonia, C. parapsilosis and C. albicans. The use of grape seed extract in combination with polyethylene glycol and propylene glycol also showed dose dependent inhibitory effect on S. aureus.

CONCLUSIONS

The results of the study showed that grape seed has potential antimicrobial effects which can be further studied and developed to be used in the treatment of infected skin-abutment interface of craniofacial implants.

Antimicrobial surfaces for craniofacial implants: state of the art

In an attempt to regain function and aesthetics in the craniofacial region, different biomaterials, including titanium, hydroxyapatite, biodegradable polymers and composites, have been widely used as a result of the loss of craniofacial bone. Although these materials presented favorable success rates, osseointegration and antibacterial properties are often hard to achieve. Although bone-implant interactions are highly dependent on the implant's surface characteristics, infections following traumatic craniofacial injuries are common. As such, poor osseointegration and infections are two of the many causes of implant failure. Further, as increasingly complex dental repairs are attempted, the likelihood of infection in these implants has also been on the rise. For these reasons, the treatment of craniofacial bone defects and dental repairs for long-term success remains a challenge. Various approaches to reduce the rate of infection and improve osseointegration have been investigated. Furthermore, recent and planned tissue engineering developments are aimed at improving the implants' physical and biological properties by improving their surfaces in order to develop craniofacial bone substitutes that will restore, maintain and improve tissue function. In this review, the commonly used biomaterials for craniofacial bone restoration and dental repair, as well as surface modification techniques, antibacterial surfaces and coatings are discussed.

Survival rates and periimplant soft tissue evaluation of extraoral implants over a mean follow-up period of three years

STATEMENT OF PROBLEM

The use of implants with extraoral prostheses provides excellent support, stability, and retention, thereby offering the potential for improving a patient's appearance and quality of life. However, few studies have examined cumulative survival rates of extraoral implants, nor have these reports documented long-term aspects of treatment, such as soft tissue health around abutments.

PURPOSE

The purpose of this study was to evaluate the survival rates and the periimplant soft tissue responses of extraoral implants used to retain facial prostheses.

MATERIAL AND METHODS

Thirty-three patients with auricular, nasal, and orbital anatomical compromise were treated with 98 craniofacial and dental implants. Of the 33 patients, 14 had auricular, 9 had nasal, and 10 had orbital defects. After a 3-month osseointegration period, implant-retained prostheses were fabricated. Following completion of treatment, each patient was seen at 6-month intervals. These examinations were recorded for this patient cohort from 25 to 50 months. Data were analyzed using Kaplan-Meier survival analysis. A 5-point scale was used to record the health of periimplant soft tissues. The unit of measure as a visit/site unit was assigned for each instance and implant site. Periimplant soft tissue reactions were assessed for auricular, nasal, and orbital defects, for each implant site used for these patients' treatments.

RESULTS

The overall cumulative survival rates were 100% for auricular, 83.3% for nasal, and 77.4% for orbital implants, respectively. The survival rates of the implants were 72.7% for those placed in irradiated sites treated without adjunctive HBO therapy, and 93.4% for implants placed in nonirradiated sites. To evaluate the response of the periimplant soft tissues to the implants, a total of 524 visits/sites were recorded. Absence of inflammation (grade 0) of the periabutment soft tissues was observed in 73.3% of the visits/sites.

CONCLUSIONS

The anatomical site into which the implant is placed has an effect on success rate. The auricular site is the most predictable implant site. Survival rates of nasal and orbital implants were found to offer promising results in achieving reliable implant prognoses in these regions. Regardless of the implant site, a decreased survival rate was observed in the irradiated sites. Periimplant soft tissue reactions were most commonly associated with lapses in hygiene.

Implant-retained nasal prosthesis for a patient following partial rhinectomy: a clinical report

Prosthetic rehabilitation of facial defects has always perplexed maxillofacial prosthodontists. Facial defects lead to functional and cosmetic deficiencies. Early rehabilitation improves patients' quality of life. Osseointegrated rehabilitation of the maxillofacial prosthetic patient presents the potential for overcoming many of the disadvantages associated with conventional retentive methods. This paper presents the clinical report of a patient who had undergone partial rhinectomy due to basal cell carcinoma. Following post-surgical healing, the patient was rehabilitated with a temporary acrylic resin nasal prosthesis retained by eyeglass frame. Later a silicone nasal prosthesis supported by an implant-retained framework was fabricated as a definitive replacement.

Zygomaticus implants for retention of nasal prostheses after rhinectomy

Malignant tumours of the nose occasionally require rhinectomy. Implant retained prostheses can give good aesthetic results. Predictable biomechanical retention of nasal prostheses can be achieved using osseointegrated implants and Brånemark intra-oral and craniofacial implants have been used previously. Zygomaticus implants are traditionally used for dental rehabilitation of the partially edentulous maxilla with severe bone resorption. We describe two patients in whom zygomaticus implants have been used to aid salvage in prosthetic reconstruction of the nose.