This review article summarizes the current modification methods employed to enhance the osseointegration properties of polyetheretherketone (PEEK), a novel biomaterial. Our analysis highlights that strategies such as surface treatment, surface modification, and the incorporation of bioactive composites can markedly improve the bioactivity of PEEK surfaces, thus facilitating their effective integration with bone tissue. However, to ensure widespread application of PEEK in the medical field, particularly in oral implantology, additional experiments and long-term clinical evaluations are required. Looking ahead, future research should concentrate on developing innovative modification techniques and assessment methodologies to further optimize the performance of PEEK implant materials. The ultimate goal is to provide the clinical setting with even more reliable solutions.
Benzophenones ; Ketones/chemistry* ; Polyethylene Glycols/chemistry* ; Osseointegration ; Humans ; Polymers ; Biocompatible Materials/chemistry* ; Surface Properties ; Prostheses and Implants ; Dental Implants

Dynamic navigation technology can "real-time guide" the implantologist to place the implant in the alveolar bone of the missing tooth area according to the preoperative design of the optimal site and path, making the whole implant surgery process more safe and precise. In order to further promote the standardized application of oral implant dynamic navigation technology, China Association of Gerontology and Geriatrics has convened distinguished experts to engage in deliberations and develop the standard. This standard covers the basic requirements, indications and contraindications, operation procedures, common complications and treatment measures, and accuracy verification. This standard can be used as a reference for the use of dynamic navigation technology in implant surgery.
Humans ; Dental Implantation, Endosseous/standards* ; Surgery, Computer-Assisted/standards* ; Dental Implants ; Surgical Navigation Systems/standards*

OBJECTIVE: To compare the influence of different emergence profile of implants in mandibular molar on the peri-implant soft tissue. METHODS: Forty-four implants were divided into two equal groups by mucosal thickness, ≥2 mm (group A) or < 2 mm (group B), and were randomly included in the test group and the control group. In the control group, the patients were treated by a prosthesis with no transmucosal modifications (subgroups A1 and B1). In groups A1 and B1, the prostheses maintained the original emergence profile of the healing abutment. In the test group, the prostheses were designed based on a width-to-height ratio (W/H) of 1.3 ∶ 1 (subgroups A2 and B2). In group A2, the buccal transmucosal configuration design was slightly concave, and in group B2, the prostheses were designed with convex buccal transmucosal configuration. Assessments were made before delivery of the definitive restoration (T0), one month (T1) and 12 months (T2) after loading. The soft tissue and prosthesis information were obtained by intraoral scan and were converted to digital models. The digital models of different time were superimposed together. Buccal mucosal W/H, emergence angle (EA) and buccal mucosal margin recession (ΔGM) were measured. RESULTS: One year after loading, the buccal mucosal margin recession in the test group (groups A2 and B2) was significantly lower than that in the control group (groups A1 and B1). The ΔGM in group A2 was significantly lower than that in group A1 (P=0.033), but in groups B1 and B2, it was not significantly different. The W/H in group A2 increased significantly one month after loading, but remained stable at one year. In the A1 group, the W/H changed little from initial to one month, but increased significantly at one year after loading. The W/H in group B2 remained stable from the beginning to one year, while in group B1, it changed little one month after loading, but increased significantly by one year. CONCLUSION When the initial mucosal thickness was ≥2 mm, the slightly concave prosthesis designed based on the biological W/H significantly maintained the level of buccal mucosa. When the mucosal thickness was < 2 mm, the slightly convex prosthesis design maintained a more stable W/H over one year.
Humans ; Mandible/surgery* ; Molar/surgery* ; Male ; Female ; Adult ; Middle Aged ; Dental Prosthesis Design ; Dental Implants ; Dental Implantation, Endosseous/methods*

OBJECTIVE: To evaluate the clinical outcomes and define the indications for a one-stage mandibular reconstruction technique that combines iliac bone flaps with immediate implant-based dentures, and to assess both the accuracy of surgical planning and the long-term success of the procedure. METHODS: A total of ten patients underwent the procedure at Peking University Hospital of Stomatology between June 2020 and August 2023. The preoperative biopsy pathology of all the patients confirmed a benign tumor. In this technique, iliac bone flaps were used for mandibular reconstruction, and immediate implant-based dentures were placed during the same surgical session. Various outcome measures were evaluated, including the accuracy of the surgical reconstruction, implant placement deviations (entry point, apical point, depth, and angle), and long-term outcomes, such as cervical bone resorption, implant survival, and the cumulative survival rate. RESULTS: Thirty-eight implants were successfully inserted into the iliac flaps of the ten patients. The median follow-up duration was 23.5 months, and no significant complications occurred during the follow-up period, such as infections, titanium plate exposure, implant loosening, or damage to the implants and dentures. The accuracy of preoperative virtual surgical planning (VSP) was highly reliable. The repeatability of the VSP model compared to the postoperative reconstructed mandible was as follows: 67.82% ±10.16% within 1 mm, 82.14% ±6.58% within 2 mm, and 90.61% ±4.62% within 3 mm. The average maximum deviation from the plan was (6.10±0.89) mm, with an average overall deviation of (1.14±0.31) mm. For the implants, deviations in critical parameters were as follows: entry point deviation was (2.02±0.58) mm, apical point deviation was (2.25± 0.66) mm, depth deviation was (1.26±0.51) mm, and angular deviation was 1.84°±1.10°. The implant survival rate remained 100% during the follow-up, with a cumulative survival rate of 97.37% from 1 to 4 years. Average cervical bone resorption was 0.94 mm. CONCLUSION The combination of iliac bone flaps with immediate implant-based dentures for one-stage mandibular reconstruction demonstrated pro-mising clinical outcomes, including high implant survival and minimal complications. This technique proved to be safe and reliable for mandibular reconstruction. However, further studies with larger sample sizes and longer follow-up periods are necessary to confirm the long-term efficacy and optimal indications for this procedure.
Humans ; Mandibular Reconstruction/methods* ; Male ; Ilium/surgery* ; Female ; Middle Aged ; Surgical Flaps ; Adult ; Mandible/surgery* ; Aged ; Dental Implantation, Endosseous/methods* ; Immediate Dental Implant Loading/methods* ; Bone Transplantation/methods* ; Dental Implants

OBJECTIVE: Dynamic navigation approaches are widely employed in the context of implant placement surgery. Implant surgery can be divided into immediate and delayed surgery according to the time of implantation. This retrospective study was developed to compare the accuracy of dynamic navigation system for immediate and delayed implantations. METHODS: In the study, medical records from all patients that had undergone implant surgery between August 2019 and June 2021 in the First Clinical Division of the Peking University School and Hospital of Stomatology were retrospectively reviewed. There were 97 patients [53 males and 44 females, average age (47.14±11.99) years] and 97 implants (delayed group: 51; immediate group: 46) that met with study inclusion criteria and were included. Implant placement accuracy was measured by the superposition of the planned implant position in the preoperative cone beam computed tomography (CBCT) image and the actual implant position in the postoperative CBCT image. The 3-dimensional (3D) entry deviation (3D deviation in the coronal aspect of the alveolar ridge), 3D apex deviation (3D deviation in the apical area of the implant) and angular deviation were analyzed as the main observation index when comparing these two groups. The 2-dimensional (2D) horizontal deviation of the entry point and apex point, and the deviation of entry point depth and apex point depth were the secondary observation index. RESULTS: The overall implant restoration survival rate was 100%, and no mechanical or biological complications were reported. The implantation success rate was 100%. The 3D entry deviation, 3D apex deviation and angular deviation of all analyzed implants were (1.146±0.458) mm, (1.276±0.526) mm, 3.022°±1.566°, respectively; while in the delayed group these respective values were (1.157±0.478) mm, (1.285±0.481) mm and 2.936°±1.470° as compared with (1.134±0.440) mm, (1.265±0.780) mm, 3.117°±1.677° in the immediate group. No significant differences (P=0.809, P=0.850, P=0.575) in accuracy were observed when comparing these two groups. CONCLUSION Dynamic computer-assisted implant surgery system promotes accurate implantation, and both the immediate and delayed implantations exhibit similar levels of accuracy under dynamic navigation system that meets the clinical demands. Dynamic navigation system is feasible for immediate implantation.
Humans ; Male ; Female ; Retrospective Studies ; Middle Aged ; Cone-Beam Computed Tomography ; Dental Implantation, Endosseous/methods* ; Surgery, Computer-Assisted/methods* ; Dental Implants ; Adult ; Surgical Navigation Systems ; Immediate Dental Implant Loading/methods* ; Imaging, Three-Dimensional

OBJECTIVE: To compare the cyclic fatigue resistance of nickel-titanium files made by 3 new heat treatment in simulated S-shaped root canals at different temperatures. METHODS: Gold heat-treated nickel-titanium files TruNatomy (25 mm, tip size 26#/0.04) and ProTaper Gold (25 mm, tip size 25#/0.08) were selected as the experimental group, M wire technique nickel-titanium file ProTaper Next (25 mm, tip size 25#/0.06) was selected as the control group. It was speculated that the Gold technique used in TruNatomy nickel-titanium file was R phase separation technique, which included a complete intermediate R-phase, increasing its flexibility. ProTaper Gold was a CM wire nickel-titanium file and the increased phase transformation temperature by heat treatment introduced martensite at room temperature, while it underwent gold heat treatment on the surface, generating an intermediate R phase during phase transformation, providing hyperelastic. ProTaper Next used M wire technique, M wire included austenite at room temperature, where heat mechanical processing introduced hardened martensite, which was incapable of participating phase transformation. Because of the lower elastic modulus of hardened martensite than austenite, the flexibility of the file was increased. Twenty instruments of each nickel-titanium file were submitted to the cyclic fatigue test by using a simulated canal with double curvatures at room tem-perature (24 ℃) and 65 ℃, 10 instruments of each nickel-titanium file were selected at each temperature (n=10). At the same temperature, the number of cyclic fatigue (NCF) and fragment length were analyzed by using One-Way analysis of variance at a significance level of P < 0.05. NCF and fragment length of the same nickel-titanium file at room temperature and 65 ℃ were compared by paired sample t test and the significance level was α=0.05. Fractured surfaces were analyzed by using scanning electron microscope. RESULTS: In double-curved canals, all the failure of the files due to cyclic fatigue was first seen in the apical curvature before the coronal curvature. At room temperature, in the apical curvature, NCF of TruNatomy was 344.4±96.6, ProTaper Gold was 175.0±56.1, ProTaper Next was 133.3±39.7, NCF of Tru Natomy was the highest (P < 0.05). In the coronal curvature, NCF of TruNatomy was 618.3± 75.3, ProTaper Gold was 327.5±111.8, ProTaper Next was 376.6±67.9, NCF of TruNatomy was also the highest (P < 0.05). There was no significant difference among the apical and coronal fragment length of the 3 nickel-titanium files (P>0.05). At 65 ℃, in the apical curvature, NCF of TruNatomy was 289.6±65.8, ProTaper Gold was 187.5±75.4, ProTaper Next was 103.0±38.5, NCF of TruNatomy was the highest (P < 0.05). In the coronal curvature, NCF of TruNatomy was 454.2±45.4, ProTaper Gold was 268.3±31.4, ProTaper Next was 283.8±31.7, NCF of TruNatomy was also the highest (P < 0.05). The apical fragment length of ProTaper Next was the highest (P < 0.05), and there was no significant difference among coronal fragment length of the 3 nickel-titanium files (P>0.05). Compared with room temperature, at 65 ℃, in the coronal curvature, NCF of TruNatomy decreased significantly (P < 0.05). The fractured surfaces of the three nickel-titanium files demonstrated typical cyclic fatigue. CONCLUSION Gold heat-treated nickel-titanium file had better cyclic fatigue resistance than M wire nickel-titanium file in S-shaped root canals.
Nickel/chemistry* ; Titanium/chemistry* ; Hot Temperature ; Root Canal Preparation/methods* ; Humans ; Materials Testing ; Gold/chemistry* ; Dental Alloys/chemistry* ; Stress, Mechanical

OBJECTIVE: To observe the long-term health condition of the single-tooth dental implant at the first molar site, and to evaluate the related factors affecting the peri-implant health. METHODS: In this study, 82 patients who were treated in the Second Clinical Division, Peking University School and Hos-pital of Stomatology from January 2008 to December 2020 were enrolled. Peri-implant tissue conditions were assessed by clinical and radiographic examination. The peri-implant probing depth (PPD), modified sulcus bleeding index (mSBI), modified plaque index (mPLI) and papilla index (PI) were recorded for 278 implants. The X-ray analysis included the restoration emergence angle (REA), the clinical crown-implant ratio (cC/I), the horizontal tooth-implant distance (HTID), the contact point level (CPL) and the embrasure surface area (ESA), etc. Kruskal-Wallis rank sum test and generalized estimation equation were used for statistical analysis. RESULTS: The average age of the patients was (40.2±9.5) years (19 to 84 years), with 33 males and 49 females. The follow-up time was (4.9±3.3) years (1 to 10 years). According to the diagnostic criteria in 2018, the prevalence of peri-implantitis in this study was 14.03% on the implant level and 21.95% on the patient level. The peri-implant health rate was 19.06% on the implant level and 18.29% on the patient level. The prevalence of peri-implant mucositis was 66.91% on the implant level and 59.75% on the patient level. At the baseline, there were statistically significant differences between the peri-implant health group and peri-implantitis group in PPD, distal HTID and mesial/distal CPL, cC/I (P < 0.05), while there was no statistically significant difference in mSBI, mPLI, PI, mesial HTID, mesial/distal REA and mesial/distal ESA between the two groups. Among the differences between follow-up and baseline, there were statistically significant dif-ferences between the two groups in PPD, mesial/distal HTID, mesial/distal CPL and mesial/distal ESA (P < 0.05). Generalized estimation equation showed that PPD, mesial/distal HTID, mesial CPL, and mesial ESA had significant positive correlations with the risk of peri-implantitis in the difference between baseline and follow-up. CONCLUSION Based on the results of this study, the peri-implant health rate is still unsatisfied, and the PPD, HTID, CPL, ESA may be related to the long-term health of the implant.
Humans ; Male ; Female ; Middle Aged ; Adult ; Dental Implants, Single-Tooth/adverse effects* ; Aged ; Aged, 80 and over ; Periodontal Index ; Young Adult ; Peri-Implantitis/epidemiology*

OBJECTIVE: To evaluate the filling quality of single cone obturation in root canal model with irregular structure (Hus&Kim Ⅴ, Yin Ⅱ-type isthmus) which established by 3D printing technology using slices and radiographic methods, in order to provide reference for clinical practice. METHODS: (1) Extracted fresh premolars with Hus&Kim Ⅴ and Yin-type Ⅱ isthmus were collected and scanned by cone-beam computed tomography (CBCT), then standard root canal models were designed and printed. Rhodamine B staining and bias fitting were used to verify the availability of the models. (2) 30 root canal models were randomly divided into 3 groups according to different filling methods (n=10). CONTROL GROUP: vertical compaction obturation; Experimental group 1: single cone obturation with 0.06-taper cone (30#); Experimental group 2: single cone obturation with 0.04-taper cone (35#), GuttaFlow 2 as canal sealers. Slices were taken at 2, 4, 6, and 8 mm from the root apex in the direction perpendicular to the long axis of the root and observed under a stereomicroscope to calculate the percentage of filling area (PAV), percentage of gutta-percha-filled area (PGFA), percentage of sealer filled area (PSFA). (3) On the basis of the above results, two groups (n=4) were selected to further analyze the filling quality by micro-computed tomography (Micro-CT), the filling volume of main root canal and the isthmus were obtained, and the percentage of filling volume (PFV) was calculated. Two-way ANOVA was used to evaluate the differences between the groups, and Tukey' s multiple comparison was used to compare the data between the groups and within the groups. RESULTS: (1) Rhodamine B staining solution could overflow the apical foramen, and the main root canal system and the isthmus area were stained, showed no remnants of support material. The 3D standard deviation of the printed model data was 0.03 mm, and the average fitting distance was 0.02 mm. (2) The PFA of the two experimental groups were both significantly lower than that of the control group (F=45.04, P < 0.01). There was no statistical difference of the PFA at apical 2 and 4 mm between the two experimental groups (P>0.01), but at the middle and coronal portions of the root canal (6, 8 mm), the PFA of the experimental group 1 was higher than that of the experimental group 2 (P < 0.01). PFA in the apical 2, 4 mm of the two experimental groups were both lower than that in the middle and coronal portions 6, 8 mm of the canal (P < 0.01). There was no difference in the PGFA and PSFA between the two experimental groups at the apical 2, 4 mm (F=2.383, P>0.01). (3) The results of Micro-CT showed that the PFV of the experimental group 1 was statistically different with the control group (F=47.33, P < 0.01). The PFV of the experimental group 1 was 54.33%±4.35% in the isthmus and 78.31%±4.21% in the main root canal, which were both lower than the PFV of the control group of 76.48%±4.89% (isthmus) and 86.90%±3.29% (main root canal, P < 0.01). The PFV of the main root canal in the experimental group 1 was higher than that in the isthmus (P < 0.01), while there was no difference between the isthmus and the main root canal in the control group (P>0.01). CONCLUSION In the irregular root canal structure with isthmus, using large-taper gutta-percha can improve the filling quality of the middle and upper part of the canal, but the percentage of filling volume in the isthmus is lower than that of the main canal, and more technical improvements are needed.
Humans ; Root Canal Obturation/methods* ; Cone-Beam Computed Tomography ; Root Canal Filling Materials ; Dental Pulp Cavity/diagnostic imaging* ; Printing, Three-Dimensional ; In Vitro Techniques ; Gutta-Percha ; Bicuspid

With the rapid development of implant dentistry, increasing attention has been paid to the long-term stability and aesthetic outcomes of dental implants, among which sufficient volume and quality of soft and hard tissues are considered crucial contributing factors for successful treatment outcomes. Among the various available tissue regeneration strategies, plasmatrix, an autologous biomaterial derived from the patient ' s own peripheral blood, has demonstrated unique and significant clinical value in the regeneration and augmentation of both soft and hard tissues associated with dental implant therapy in recent years. This notable potential is primarily attributed to its rich content of multiple growth factors, viable cells, and a supportive fibrin scaffold, along with its excellent biocompatibility, tunable biodegradation profile, and a relatively simple and rapid preparation process that does not require complex laboratory equipment. As a result, its clinical applications have been continuously expanding across a wide range of indications. Based on a comprehensive review of the existing literature and current research evidence, this article provides an in-depth summary of the advancements in both basic science and clinical applications of plasmatrix in the context of implant dentistry. Particular attention is given to its classification from a materials science perspective, underlying molecular mechanisms, biological effects in promoting tissue regeneration, and its implementation under different clinical scenarios. Furthermore, the article discusses unresolved technical challenges and existing controversies, and outlines potential future directions for research and technological innovation, aiming to provide robust evidence-based guidance for clinical practice as well as a theoretical and methodological reference for future scientific investigations.
Humans ; Biocompatible Materials/therapeutic use* ; Dental Implants ; Tissue Scaffolds ; Fibrin/therapeutic use* ; Tissue Engineering/methods* ; Dental Implantation/methods* ; Dental Implantation, Endosseous/methods*

OBJECTIVE: To assess the osteogenesis height in maxillary sinus segment one year after zygomatic implantation by imaging methods, and evaluate the influence of patient factors, maxillary sinus anatomical factors and surgical factors on postoperative osteogenesis height. METHODS: This study is a retrospective study, including patients who underwent zygomatic implantation and whose zygomatic implants passed through the maxillary sinus at the Department of Implantology, Peking University School and Hospital of Stomatology from July 2017 to January 2022. Preoperative and postoperative cone beam CT (CBCT)was taken to measure and calculate the average osteogenesis height (AOH) in maxillary sinus segment of the zygomatic implants, then the residual bone height, the width and morphology of the maxillary sinus floor in the buccal and palatal directions were measured. Besides, the integrity of Schneiderian membrane during implant surgery, and the general information of the patients and zygomatic implants were recorded. By comparing anatomical situations and surgical characteristics, the differences of AOH under different conditions were analyzed. Then AOH was divided into two groups (obvious osteogenesis group and non-obvious osteogenesis group) using the median as the threshold, and the influencing factors of osteogenesis were evaluated using mixed effect generalized linear model univariable and multivariable analysis. RESULTS: A total of 47 zygomatic implants were implanted in 24 patients. During the average follow-up period of 12.1 months, there was no implant failure, and the implant survival rate was 100%. Postoperative CBCT showed that 43 zygomatic implants had osteogenic images in the maxillary sinus segment, most of which originated from the floor of the maxillary sinus, and the median AOH was 3.1 mm [interquartile range (IQR): 4.0 mm]. In terms of maxillary sinus width, there were 31 cases (66.0%) of wide type and 16 cases (34.0%) of narrow type. In the aspect of buccal and palatal morphology, 17 cases were taper (36.2%), 20 cases were round (42.6%), and 10 cases were flat (21.3%). The median of residual bone height was 2.8 mm (IQR: 2.2 mm) before operation. Univa-riate analysis of mixed effect generalized linear model showed that postoperative obvious osteogenic rate was related to the residual bone height (OR=2.09, P=0.006). Multivariate analysis showed that the resi-dual bone height (OR=2.55, P=0.022) and the shape of a taper maxillary sinus (OR=11.44, P=0.040) had a significant impact on the postoperative obvious osteogenic rate. CONCLUSION The maxillary sinus floor showed osteogenic images 1 year after the zygomatic implantation surgery. Larger residual bone height and the shape of a taper maxillary sinus may be favorable factors for osteogenesis.
Humans ; Maxillary Sinus/surgery* ; Cone-Beam Computed Tomography ; Retrospective Studies ; Zygoma/diagnostic imaging* ; Male ; Female ; Osteogenesis/physiology* ; Middle Aged ; Adult ; Dental Implants ; Aged ; Dental Implantation, Endosseous/methods*