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*

Peri-implant keratinized mucosa (PIKM) augmentation refers to surgical procedures aimed at increasing the width of PIKM. Consensus reports emphasize the necessity of maintaining a minimum width of PIKM to ensure long-term peri-implant health. Currently, several surgical techniques have been validated for their effectiveness in increasing PIKM. However, the selection and application of PIKM augmentation methods may present challenges for dental practitioners due to heterogeneity in surgical techniques, variations in clinical scenarios, and anatomical differences. Therefore, clear guidelines and considerations for PIKM augmentation are needed. This expert consensus focuses on the commonly employed surgical techniques for PIKM augmentation and the factors influencing their selection at second-stage surgery. It aims to establish a standardized framework for assessing, planning, and executing PIKM augmentation procedures, with the goal of offering evidence-based guidance to enhance the predictability and success of PIKM augmentation.
Humans ; Consensus ; Dental Implants ; Mouth Mucosa/surgery* ; Keratins

Dental pulp-dentin complex defects remain a major unresolved problem in oral medicines. Clinical therapeutic methods including root canal therapy and vital pulp therapy are both considered as conservative strategies, which are incapable of repairing the pulp-dentin complex defects. Although biomaterial-based strategies show remarkable progress in antibacterial, anti-inflammatory, and pulp regeneration, the important modulatory effects of nerves within pulp cavity have been greatly overlooked, making it challenging to achieve functional pulp-dentin complex regeneration. In this study, we propose an injectable bioceramics-containing composite hydrogel in combination of Li-Ca-Si (LCS) bioceramics and gelatin methacrylate matrix with photo-crosslinking properties. Due to the sustained release of bioactive Li, Ca and Si ions from LCS, the composite hydrogels possess multiple functions of promoting the neurogenic differentiation of Schwann cells, odontogenic differentiation of dental pulp stem cells, and neurogenesis-odontogenesis couples in vitro. In addition, the in vivo results showed that LCS-containing composite hydrogel can significantly promote the pulp-dentin complex repair. More importantly, LCS bioceramics-containing composite hydrogel can induce the growth of nerve fibers, leading to the re-innervation of pulp tissues. Taken together, the study suggests that LCS bioceramics can induce the innervation of pulp-dentin complex repair, offering a referable strategy of designing multifunctional filling materials for functional periodontal tissue regeneration.
Dental Pulp/drug effects* ; Hydrogels/pharmacology* ; Animals ; Ceramics/pharmacology* ; Dentin/drug effects* ; Biocompatible Materials/pharmacology* ; Rats ; Gelatin ; Regeneration/drug effects* ; Cell Differentiation/drug effects* ; Injections ; Humans ; Odontogenesis/drug effects*

OBJECTIVES: This study aims to explore the effect of improving clinical efficiency by replacing traditional impression workflow with centralized digital impression workflow. METHODS: The department of prosthodontics in Center of Stomatology, Peking University Shenzhen Hospital has improved the clinical workflow by replacing the traditional impression made by doctors using impression materials for each patient with a centralized digital impression made by one technician for all patients in the department. This cross-sectional study recorded the chairside time required for impression taking in patients undergoing single posterior zirconia full crown restoration before clinical process improvement; the time required for centralized digital impression production; the comfort level of patients; and the adjacency relationship, occlusal contact relationship, and time required for prostheses adjusting (i.e., whether centralized digital impressions would compromise the quality of pro-stheses and increase the time of prostheses adjusting). RESULTS: The average time to make a traditional impression was (9.98±1.41) min, and the average time required for each patient to make a centralized digital impression was (5.98±1.49) min, which was shorter than that to used make a traditional impression (P<0.05). Centralized digital impression made patients feel more comfortable compared with traditional impression (P<0.05). The adjacency relationship of restorations by centralized digital impression was more appropriate (P<0.05), and no significant difference in occlusal relationship was found (P>0.05). The time required for adjusting prostheses also had no significant differences (P>0.05). CONCLUSIONS Centralized digital impression can improve clinical efficiency for patients undergoing single posterior zirconia crown restoration. The time for impression taking is shorter, and patients feel more comfortable without compromising the quality of the prostheses.
Humans ; Cross-Sectional Studies ; Dental Impression Technique ; Crowns ; Zirconium ; Workflow ; Computer-Aided Design ; Time Factors ; Dental Impression Materials

OBJECTIVES: To study the clinical effect of the L-shape technique combined with concentrated growth factor on the horizontal bone defects of maxillary anterior teeth. METHODS: Twenty-five implants from 25 patients who underwent single maxillary anterior tooth implantation with simultaneous bone grafting were selected as the study subjects. Based on the bone grafting techniques, the patients were divided into a test group (L-shaped technique with guided bone regeneration combined with concentrated growth factor, 11 cases) and a control group (traditional guided bone regeneration combined with concentrated growth factor, 14 cases). The early discomfort and wound healing conditions in the two groups at two weeks after surgery were compared. The horizontal bone thickness, vertical bone thickness, and grayscale values in the augmentation area were measured immediately postsurgery and six months after surgery. Implant stability, hard tissue resorption within six months, and grayscale values were compared between the two groups. RESULTS: Differences in early discomfort, wound healing, implant stability, and grayscale values between the two groups were not statistically significant (P>0.05). Vertical bone thickness in the test group was significantly better than that in the control group at six months after surgery (P<0.05). The variation in horizontal bone thickness in the test group was significantly higher than that in the control group (P<0.05). CONCLUSIONS The application of the L-shape technique with concentrated growth factor for horizontal bone defects in the anterior maxillary area yielded satisfactory short-term results in terms of bone augmentation, early discomfort, wound healing, and implant stability at six months after surgery.
Humans ; Maxilla/diagnostic imaging* ; Intercellular Signaling Peptides and Proteins/therapeutic use* ; Wound Healing ; Bone Transplantation/methods* ; Dental Implantation, Endosseous/methods* ; Bone Regeneration ; Male ; Female ; Adult ; Dental Implants, Single-Tooth ; Middle Aged

Peri-implantitis is a pathologic condition associated with dental plaque that occurs in the implant tissue and is characterized by inflammation of the mucous membrane surrounding the implant, followed by the progressive loss of supporting bone. In this study, a case of guided bone regeneration therapy based on plaque control of peri-implant inflammation was reported. Four years after surgery for the left second premolar implant, the patient presented with "left lower posterior tooth swelling and discomfort for more than 2 years". The X-ray periapical film showed a decrease in distal bone mineral density of implant, and the clinical diagnosis was peri-implantitis of the left second premolar. Implants underwent guided bone regeneration and regular periodontal maintenance treatment. Re-examination at 3.5 months, 11 months, 18 months, and 7 years showed that the alveolar bone height and bone mineral density were stable, and the periodontal depth became shallow. However, the gingival recession was mild. In the present case, follow-up at 7 years demonstrated that the clinical periodontal indexes could be remarkably improved after complete periodontal treatment for peri-implantitis, and the alveolar bone could be well restored and regenerated.
Humans ; Peri-Implantitis/etiology* ; Follow-Up Studies ; Bone Regeneration ; Guided Tissue Regeneration, Periodontal/methods* ; Dental Plaque/prevention & control* ; Male ; Female ; Dental Implants/adverse effects*

OBJECTIVES: This study aims to use 3D prin-ting technology based on the principle of stereo lithography apparatus (SLA) to shape dental lithium disilicate ceramics and study the effects of different slurry proportions on the microstructure and properties of heat-treated samples. METHODS: The experimental group comprised lithium disilicate ceramics manufactured through SLA 3D printing, and the control group comprised lithium disilicate ceramics (IPS e.max CAD) fabricated through commercial milling. An array of different particle sizes of lithium disilicate ceramic powder materials (nano and micron) was selected for mixing with photocurable acrylate resin. The proportion of experimental raw materials was adjusted to prepare five groups of ceramic slurries for 3D printing (Groups S1-S5) on the basis of rheological properties, stability, and other factors. Printing, debonding, and sintering were conducted on the experimental group with the optimal ratio, followed by measurements of microstructure, crystallographic information, shrinkage, and mechanical properties. RESULTS: Five groups of lithium disilicate ceramic slurries were prepared, of which two groups with high solid content (75%) (Groups S2 and S3) were selected for 3D printing. X-ray diffraction and scanning electron microscopy results showed that lithium disilicate was the main crystalline phase in Groups S2 and S3, and its microstructure was slender, uniform, and compact. The average grain sizes of Groups S2 and S3 were (559.79±84.58) nm and (388.26±61.49) nm, respectively (P<0.05). Energy spectroscopy revealed that the samples in the two groups contained a high proportion of Si and O elements. After heat treatment, the shrinkage rate of the two groups of ceramic samples was 18.00%-20.71%. Test results revealed no statistical difference in all mechanical properties between Groups S2 and S3 (P>0.05). The flexural strengths of Groups S2 and S3 were (231.79±21.71) MPa and (214.86±46.64) MPa, respectively, which were lower than that of the IPS e.max CAD group (P<0.05). The elasticity modulus of Groups S2 and S3 were (87.40±12.99) GPa and (92.87±19.76) GPa, respectively, which did not significantly differ from that of the IPS e.max CAD group (P>0.05). The Vickers hardness values of Groups S2 and S3 were (6.53±0.19) GPa and (6.25±0.12) GPa, respectively, which were higher than that of the IPS e.max CAD group (P<0.05). The fracture toughness values of Groups S2 and S3 were (1.57±0.28) MPa·m^0.5 and (1.38±0.17) MPa·m^0.5, respectively, which did not significantly differ from that of the IPS e.max CAD group (P>0.05). CONCLUSIONS The combination of lithium disilicate ceramic powders with different particle sizes can yield a slurry with high solid content (75%) and suitable viscosity and stability. The dental lithium disilicate ceramic material is successfully prepared by using 3D printing technology. The 3D-printed samples show a small shrinkage rate after heat treatment. Their microstructure conforms to the crystal phase of lithium disilicate ceramics, and their mechanical properties are close to those of milled lithium disilicate ceramics.
Printing, Three-Dimensional ; Dental Porcelain/chemistry* ; Ceramics/chemistry* ; Materials Testing ; Particle Size

In the realm of oral implantology, currently, there is no unanimous consensus or authoritative guideline regarding how to conduct implant restoration for cases involving oroantral communication or oroantral fistula. In these cases, the bony plate of the maxillary sinus floor is discontinuous, the oro-sinus mucosa is in communication, and a vertical alveolar bone defect exists. This paper presents a case of a patient with two oroantral communications who successfully underwent implant restoration via simple staged surgeries. Following a 2-year clinical follow-up, the implant remains in good condition, and the patient expresses satisfaction. The objective of this paper is to offer a simple, safe, and readily-promotable new approach for such cases.
Humans ; Dental Implantation, Endosseous/methods* ; Dental Implants ; Maxillary Sinus/surgery* ; Oroantral Fistula/surgery*

OBJECTIVES: This study aims to evaluate the short- to medium-term clinical efficacy of demineralized dentin matrix (DDM) particles applied during the immediate implantation of alveolar bone defects in the posterior region. METHODS: A total of 76 patients with 110 simple taper retentive implants were included in the conducted study and divided into Groups A and B in accordance with the bone grafting materials. Cone beam computed tomography and panoramic radiographs were taken immediately after implant surgery, immediate crown repair, and final follow-up time. The average follow-up time for Groups A and B was recorded. The primary observed clinical indicators were overall survival rate of the implant, bone resorption of the mesial and distal margins of the implant, buccal bone width resorption at the platform level and 1 mm below the platform, and bone height of the implant. Implant complication was a secondary observed clinical indicator. RESULTS: During the 1-to-5-year follow-up observation period, the mean follow-up of Group A was 38.2 months while that of Group B was 39.9 months. In Group A, two implants failed, one of which fractured, and implant overall survival rate was 96.4%. Four implants failed in Group B due to peri-implantitis, and implant overall survival rate was 92.6%. No statistically significant difference in implant overall survival rate was found between the two groups (P>0.05). In Group A, the average bone resorption in the mesial and distal margins of the implants was (1.011±2.047) mm and (0.841±2.183) mm, respectively. In Group B, the average bone resorption of the mesial and distal margins of the implants was (1.546±1.778) mm and (1.431±1.909) mm, respectively. No statistically significant difference was noted between the two groups (P>0.05). In Group A, buccal bone width resorption at the platform level and 1 mm below the platform of the implant was (0.782±2.084) mm and (0.681±2.307) mm, respectively. In Group B, buccal bone width resorption at the platform level and 1 mm below the platform of implant was (1.071±1.474) mm and (0.949±1.909) mm, respectively. No statistically significant difference was found between the two groups (P>0.05). In Group A, the buccal bone height of resorption of the implant was (1.044±2.214) mm. In Group B, the buccal bone height of resorption of the implant was (1.075±1.456) mm. No statistically significant difference in bone height was observed between the two groups (P>0.05). CONCLUSIONS During the 1-to-5-year follow-up observation period, DDM particles can effectively increase the height and width of alveolar bone, and they can achieve the same effect of maintaining alveolar bone contour and bone augmentation compared with deproteinized inorganic calf bone. DDM particles can be used as a potential new bone grafting material for the treatment of bone defects in clinical practice.
Humans ; Follow-Up Studies ; Dentin ; Cone-Beam Computed Tomography ; Dental Implants ; Male ; Female ; Adult ; Alveolar Bone Loss/surgery* ; Middle Aged ; Bone Transplantation ; Radiography, Panoramic ; Dental Implantation, Endosseous/methods* ; Immediate Dental Implant Loading

OBJECTIVES: This study aimed to investigate the influence of the dimensional stability of 3D printed resin master model on the replication accuracy of implant replicas. METHODS: Ten digital impressions of patients undergoing continuous crowns or fixed bridge restoration supported by two implants were obtained, and resin models with implant replicas were 3D printed. Scanning rods were fixed on the replicas 3, 7, and 14 days after printing. The 3D, linear, and angular deviations of the scanning rods at different times were analyzed through Geomagic Wrap 2021 software. RESULTS: The position of the replicas shifted mesiolingually, in the same direction as the shrinkage of the model. From day 7 onward, the 3D, distance linear, and angular deviations of the replicas (scanning rod) significantly increased compared with those on the 3rd day (P<0.05). On the 14th day, the changes were even more pronounced, with the above deviations showing statistical significance (P<0.05) compared with those for the 3-day and 7-day groups. No statistical difference in height linear deviation was observed among the groups. CONCLUSIONS The insufficient dimensional stability of 3D printed resin models can lead to changes in the relative position and angle of the replicas, thereby affecting the accuracy of the replicas in recreating the implant's position. Complete manufacturing of prosthesis is recommended within 7 days after the model is printed.
Printing, Three-Dimensional ; Humans ; Dental Implants ; Models, Dental ; Dental Impression Technique ; Crowns