Titanium abutments are considered the gold standard due to their mechanical strength, stability, and high survival rates.209 However, one shortcoming is the gray color that shows through the soft tissue, resulting in compromised esthetic outcomes. Titanium abutments may be treated to create a gold-colored titanium nitride surface for better esthetics. In a human study, titanium nitride–coated surfaces demonstrated reduced colonization of bacteria as compared with standard machined titanium.210 Zirconia abutments are esthetically pleasing with similar biologic integration,63,211–217 but the material strength is inferior to that of titanium abutments.209
Several clinical and histologic studies compare titanium and zirconia abutments. Peri-implant mucosa response was evaluated in subjects via gingival biopsy from around titanium and zirconia healing caps. Titanium healing caps showed a high degree of gingival inflammation when compared with zirconia samples, indicating better biocompatibility of the zirconia.217 A 3-year randomized clinical study compared titanium and zirconia abutments for single implant-supported crowns around canines and posterior tooth sites. Periodontal parameters—probing depth, plaque control, bleeding upon probing, and bone loss—were similar for both abutments. Interestingly, in this study both zirconia and titanium abutments caused similar peri-implant mucosal discoloration compared with the gingiva around natural teeth.218 A meta-analysis of 5-year survival rates and incidences of complications associated with ceramic (mostly zirconia) and metal abutments was performed.209 The survival rates were 99% and 97.4% for ceramic and metal abutments, respectively. Abutment screw loosening was the most common technical problem, with incidence of 6.9% for ceramic and 15.9% for metal abutments. Esthetic problems were more frequent for metal abutments. Biologic complications were 5.2% for ceramic abutments and 7.7% for metal abutments. Over-all, however, the survival rates and technical and biologic complications were similar for both the ceramic and metal abutments.209
Oral Hygiene
A classic study by Loe et al in 1965 demonstrated a cause and effect relationship between bacterial plaque and gingival inflammation.219 When nine participants abstained from all measures of oral hygiene, gingival inflammation developed within 10 to 21 days. Once oral hygiene was resumed, the gingival inflammation resolved in all participants within a week. It was concluded that bacterial plaque was essential in the production of gingival inflammation. The same cause and effect relationship between plaque accumulation and development of peri-implant mucositis around dental implants was demonstrated when patients were asked to abstain from all oral hygiene practices for 3 weeks.220
The microflora around dental implants originates from the oral cavity with similar microbial composition to that surrounding the natural teeth in health. The microflora of failing implants is similar to that of periodontal disease. This may be the result of contamination of the peri-implant sites by periodontal pathogens residing in periodontal pockets.221–223 Effective plaque control performed by the patient and professional periodontal supportive therapy around natural teeth and dental implants are vital to prevent development and progression of periodontal disease.224–226
Adequate plaque control to ensure periodontal stability can be achieved by means of mechanical cleansing devices such as manual or electric toothbrushes, floss, interdental brushes, oral irrigators, and mouthwashes. Toothbrushes are the most commonly used mechanical cleansing device used by patients and recommended by dental professionals. When electric toothbrushes were compared with manual toothbrushes, there was no statistically significant difference in regard to efficacy in plaque removal and gingival health.227–230 Plaque removal in interproximal sites can be accomplished by means of dental floss and interdental brushes. Interdental brushes are more effective in removing bacterial plaque and should be indicated in patients with open interproximal spaces, while dental floss should be indicated in patients with closed interproximal sites.226,227
Chlorhexidine is an effective antiplaque agent that is mainly used as a mouthwash. It is usually indicated for short-term use for presurgical or healing phases of periodontal or implant-related surgery or for intermittent use for patients with high caries risk or extensive prosthetic reconstructions.231 Long-term use is not indicated due to adverse effects, including staining of the teeth and tongue, bitter aftertaste, taste alterations, and increased calculus formation.232–234
Home care around dental implants is not much different from that around natural teeth. Traditional mechanical cleansing devices such as manual or electric toothbrushes, interdental brushes, conventional floss (with or without a threader as needed), and Super Floss (Oral-B) are usually recommended around dental implants. However, there is not enough evidence in the literature to indicate which is the most effective oral home care instrument to maintain healthy tissues around dental implants. Electric toothbrushes are effective and safe around implants, but their efficacy is comparable to that of manual tooth brushing around implant-supported restorations.235–237
It is extremely important to establish a scheduled maintenance program for patients with dental implants. They must be evaluated at regular intervals for clinical parameters, and the areas surrounding the implants must be debrided. Customized supportive periodontal therapy should be performed and tailored to each patient, with recall intervals ranging from 1 to 6 months (average of 3 months) based on the level of oral hygiene, calculus formation, periodontal status, and various host factors.238–242
At each evaluation, clinical parameters such as probing depth, clinical attachment level, bleeding, mobility, and plaque control should be recorded. Radiographic images should be obtained periodically to assess bone levels and proper fit of the abutment.243 Cautious debridement around dental implants is imperative to prevent damage to the implant surface. Scratches on the titanium surface may favor plaque accumulation and corrosion of the titanium as well as decreases in cell adhesion and attachment.244,245 In vitro and animal studies evaluated the ideal instruments to clean around titanium abutments. Interdental brushes, soft toothbrushes, plastic scalers, and rubber cups without paste resulted in clean surfaces with roughness comparable to that of an untreated abutment. Air polishing, metal scalers, and ultrasonic tips resulted in roughened titanium surfaces.246–248
The authors recommend a cautious, conservative maintenance approach for implant patients. Recall intervals should begin at 3-month intervals, increasing by 1-month increments as the absence of clinical inflammation signs indicates. All sites should be probed using a metal probe for accuracy, and all changes should be recorded. All negative changes from healed site baselines should dictate more aggressive care. Home care efficacy should be monitored and should influence the recall interval as well. All teeth and implants should be debrided. Plastic curettes, plastic-covered ultrasonic tips, and plain rubber cups should be the only items used on titanium surfaces. With this approach, health can be maintained, and negative trends can be intercepted early.
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