Follow-up examination of cement-retained implant restorations using perioscopy technology

Background: Implant restorations can be screw-retained or cement-retained. Thereby the careful removal of excess cement may become a problematic procedure, particularly if margins of the restorations are subgingival. The removal of cement residues may lead to pen-implant inflammation (pen-implant mucositis, peri-implantitis). The aim of this study was to determine the existence of excess zinc phosphate cement in fixed partial dentures and single crowns with subgingival margins on implants using the dental endoscope Dental View DV2 (Dental View, Lake Forest, CA, USA). Methods: In a prospective study a total of 31 implants (based on 25 subjects) were examined by the Dental View DV2. This included the assessment of parameters such as probing depths (ST), bleeding on probing (BOP), and depth of subgingival margins of single crowns and fixed partial dentures. A total of 6 implant sites were determined subgingivally: mesiobuccal, buccal, distobuccal, mesiolingual, lingual, and distolingual. Results: Cement remnants were observed in 60% of the subjects and in 51.6% of the implants, with 17.7% subjected to the implant sites. Most cement remnants were identified distolingually (30.3%) and distobuccally (24.2%). Further, diagnostics showed that pre-dispositional sites of premolars are in buccal and distolingual positions; and pre-dispositional sites of molars are located in distobuccal and distolingual positions. In cases of cement residue, it was found that the amount of BOP positive sites was determined at 54.5%. Analysis of pocket depths gained a mean value of 3.1 mm +/- 1.2 mm. If cement remnants were present, the mean pocket depth was 3.5 mm +/- 1.3 mm. Conclusion: This study demonstrated that dentists should be aware of potential problems when cementing restorations with subgingival margins. Clinicians may leave cement remnants that could result in pen-implant inflammation. The dental endoscope, Dental View DV2, should be used to control the removal of cement from subgingival margins of single crowns and fixed partial dentures, especially in restorations with deep subgingival margins.