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The reuse of healing abutments (HAs) has become common practice in implant dentistry for economic concerns and the aim of this in vitro study was to assess the effect of sodium hypochlorite (NaOCl) in decontamination of HAs. A total of 122 HAs (used and sterilized [n = 107]; new [n = 15]) were procured from 3 centers, of which 3 samples were discarded due to perforation in the sterilization pouch. For sterility assessment, the used HAs (n = 80) were cultured in Brain Heart Infusion Broth (BHI) and potato dextrose agar (PDA); bacterial isolates were identified in 7 samples. Also, 24 used HAs were stained with phloxine B, photographed, and compared to new HAs (n = 5). A scanning electron microscope (SEM) assessed the differences between 2 sets of HAs, after which the 7 contaminated HAs along with 24 used HAs from staining experiment (total: 31) were subsequently treated with sodium hypochlorite (NaOCl) and SEM images were observed. About 8.75% of HAs tested positive in bacterial culture; Streptococcus sanguis, Dermabacter hominis, Staphylococcus haemolyticus, and Aspergillus species were isolated. Phloxine B staining was positive for used and sterilized HAs compared to controls. The SEM images revealed deposits in the used HAs and although treatment with NaOCl eliminated the contamination of cultured HAs, the SEM showed visible debris in the HA thread region. This in vitro study concluded that SEM images showed debris in used HAs at screw-hole and thread regions even though they tested negative in bacterial culture. The treatment with NaOCl of used HAs showed no bacterial contamination but the debris was observed in SEM images. Future studies on the chemical composition, biological implications, and clinical influence is warranted before considering reuse of HAs.

The purpose of this study was to assess the effects of a modified implant abutment design on peri-implant soft and hard tissues in dogs. Three months after extraction of mandibular premolar teeth, 3 dental implants were placed in each side of the jaw using a 1-stage approach. Implants on one side of the mandible received standard abutments (control), and implants on the contralateral side received modified, patented, grooved abutments (test). Two months after implant placement, animals were euthanized and specimens were prepared for histologic and histomorphometric assessment. The linear distance (in micrometers) was measured from the implant shoulder (IS) to the following landmarks: gingival margin (GM; distance IS-GM), most apical position of the junctional epithelium (JE; distance IS-JE), and bone crest (BC; distance IS-BC). Percent of bone-to-implant contact was also measured. Histologic assessment revealed that all implants were osseointegrated and that interimplant gingival fibers between test abutments appeared to be more numerous and organized than control abutments. The IS-GM and IS-JE distances in test implants were greater than the corresponding distances in control implants (P = .024 and P = .015, respectively), whereas crestal bone loss (IS-BC) was greater for control implants than test implants (P = .037). There were no differences between control and test implants in bone-to-implant contact (P = .69), which averaged close to 50%. These results suggest that the modified groove design incorporated in standard abutments confers both soft and hard tissue benefits.