Dental implants have restored masticatory function to over 100 000 000 individuals, yet almost 1 000 000 implants fail each year due to peri-implantitis, a disease triggered by peri-implant microbial dysbiosis. Our ability to prevent and treat peri-implantitis is hampered by a paucity of knowledge of how these biomes are acquired and the factors that engender normobiosis. Therefore, we combined a 3-month interventional study of 15 systemically and periodontally healthy adults with whole genome sequencing, fine-scale enumeration and graph theoretics to interrogate colonization dynamics in the pristine peri-implant sulcus. We discovered that colonization trajectories of implants differ substantially from adjoining teeth in acquisition of new members and development of functional synergies. Source-tracking algorithms revealed that this niche is initially seeded by bacteria trapped within the coverscrew chamber during implant placement. These pioneer species stably colonize the microbiome and exert a sustained influence on the ecosystem by serving as anchors of influential hubs and by providing functions that enable cell replication and biofilm maturation. Unlike the periodontal microbiome, recruitment of new members to the peri-implant community occurs on nepotistic principles. Maturation is accompanied by a progressive increase in anaerobiosis, however, the predominant functionalities are oxygen-dependent over the 12-weeks. The peri-implant community is easily perturbed following crown placement, but demonstrates remarkable resilience; returning to pre-perturbation states within three weeks. This study highlights important differences in the development of the periodontal and peri-implant ecosystems, and signposts the importance of placing implants in periodontally healthy individuals or following the successful resolution of periodontal disease.
Humans ; Dental Implants/microbiology* ; Microbiota ; Male ; Adult ; Female ; Biofilms ; Middle Aged ; Peri-Implantitis/microbiology*

OBJECTIVE: To describe the submucosal microbial profiles of peri-implantitis and healthy implants, and to explore bacteria that might be correlated with clinical parameters. METHODS: In the present cross-sectional study, 49 patients were recruited. Each patient contributed with one implant, submucosal biofilms were collected from 20 healthy implants and 29 implants with peri-implantitis. DNA was extracted and bacterial 16S ribosomal RNA (16S rRNA) genes were amplified. Submucosal biofilms were analyzed using 16S rRNA sequencing at Illumina MiSeq platform. Differences between the groups were determined by analyzing α diversity, microbial component and microbial structure. The potential correlation between the bacteria with pocket probing depth (PPD) of peri-implant calculated by Spearman correlation analysis. RESULTS: The α diversity of submucosal microbial of health group was significantly lower than that in peri-implantitis group (Chao1 index: 236.85±66.13 vs. 150.54±57.43, P < 0.001; Shannon index: 3.42±0.48 vs. 3.02±0.65, P=0.032). Principal coordinated analysis showed that the submucosal microbial structure had significant difference between healthy and peri-implantitis groups [R²=0.243, P=0.001, analysis of similarities (ANOSIM)]. Compared with healthy implants, relative abundance of periodontal pathogens were higher in peri-implantitis, including members of the red complex (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola) and some members of orange complex (Precotella intermedia, Eubacterium nodatum, Parvimonas micra), as well as some new periodontal pathogens, such as Fillifactor alocis, Fretibacterium fastidiosum, Desulfobulbus sp._HMT_041, and Porphyromonas endodontalis. Spearman correlation analysis revealed that the relative abundance of Treponema denticola (r=0.686, P < 0.001), Tannerella forsythia (r=0.675, P < 0.001), Fretibacterium sp. (r=0.671, P < 0.001), Desulfobulbus sp._HMT_041 (r=0.664, P < 0.001), Filifactor alocis (r=0.642, P < 0.001), Fretibacterium fastidiosum (r=0.604, P < 0.001), Porphyromonas gingivalis (r=0.597, P < 0.001), Porphyromonas endodontalis (r=0.573, P < 0.001) were positive correlated with PPD. While the relative abundance of Rothia aeria (r=-0.615, P < 0.001) showed negatively correlation with PPD. CONCLUSION Marked differences were observed in the microbial profiles of healthy implants and peri-implantitis. The members of red and orange complex as well as some new periodontal pathogens seem to play an important role in peri-implant disease. Compared with healthy implants, the submucosal microbial of peri-implantitis were characterized by high species richness and diversity.
Humans ; Peri-Implantitis/microbiology* ; Cross-Sectional Studies ; RNA, Ribosomal, 16S/genetics* ; Bacterial Load ; Porphyromonas gingivalis ; Dental Implants

Sub-gingival anaerobic pathogens can colonize an implant surface to compromise osseointegration of dental implants once the soft tissue seal around the neck of an implant is broken. In vitro evaluations of implant materials are usually done in monoculture studies involving either tissue integration or bacterial colonization. Co-culture models, in which tissue cells and bacteria battle simultaneously for estate on an implant surface, have been demonstrated to provide a better in vitro mimic of the clinical situation. Here we aim to compare the surface coverage by U2OS osteoblasts cells prior to and after challenge by two anaerobic sub-gingival pathogens in a co-culture model on differently modified titanium (Ti), titanium-zirconium (TiZr) alloys and zirconia surfaces. Monoculture studies with either U2OS osteoblasts or bacteria were also carried out and indicated significant differences in biofilm formation between the implant materials, but interactions with U2OS osteoblasts were favourable on all materials. Adhering U2OS osteoblasts cells, however, were significantly more displaced from differently modified Ti surfaces by challenging sub-gingival pathogens than from TiZr alloys and zirconia variants. Combined with previous work employing a co-culture model consisting of human gingival fibroblasts and supra-gingival oral bacteria, results point to a different material selection to stimulate the formation of a soft tissue seal as compared to preservation of osseointegration under the unsterile conditions of the oral cavity.
Acid Etching, Dental ; methods ; Alloys ; chemistry ; Bacterial Adhesion ; physiology ; Bacteriological Techniques ; Biofilms ; Cell Adhesion ; physiology ; Cell Culture Techniques ; Cell Line, Tumor ; Cell Movement ; physiology ; Ceramics ; chemistry ; Coculture Techniques ; Dental Alloys ; chemistry ; Dental Etching ; methods ; Dental Implants ; microbiology ; Dental Materials ; chemistry ; Dental Polishing ; methods ; Humans ; Osseointegration ; physiology ; Osteoblasts ; physiology ; Porphyromonas gingivalis ; physiology ; Prevotella intermedia ; physiology ; Surface Properties ; Titanium ; chemistry ; Yttrium ; chemistry ; Zirconium ; chemistry

OBJECTIVETo evaluate the effects of local-delivery of 25% metronidazol gel and mechanical cleaning using ultrasonic carbon fiber tip on dental implants with peri-implantitis.

METHODS27 implants with peri-implantitis were randomly assigned to receiving either 25% metronidazol gel treatment or carbon fiber tip ultrasonic scaling. All parameters including plaque index (PLI), probing depth (PD) of pocket, sulcular bleeding index (SBI), and BANA enzyme analysis were measured at baseline, 1, 2, 6 and 12 weeks after treatment.

RESULTSStatistically significant decrease (P < 0.05) in SBI, BANA test and PLI occurred in both treatment groups at all time intervals compared to baseline. PD had a decreasing tendency in both groups, but only metronidazole group reached statistically significant level (P < 0.05) at 2 and 6 week intervals compared to baseline. None of the treatment modalities produced any side effects on the implant and peri-implant tissues.

CONCLUSIONSBoth 25% metronidazol gel and mechanical cleaning using ultrasonic carbon fiber tip can be safely and effectively used in the treatment of peri-implant diseases.

Adult ; Anti-Infective Agents ; therapeutic use ; Carbon ; Dental Implants ; adverse effects ; microbiology ; Female ; Humans ; Male ; Metronidazole ; therapeutic use ; Middle Aged ; Periodontitis ; etiology ; therapy ; Time Factors ; Treatment Outcome ; Ultrasonics