Effect of Dental Implant System-Assisted Tooth Intentional Replantation in the Treatment of Anterior Teeth with Pathological Tooth Flaring, Drifting and Elongation in Patients with Stage III/IV Periodontitis: a Case Series.

OBJECTIVE: To investigate the clinical effect of implant-assisted dental intentional replantation (IR) for the treatment of "drifted" anterior periodontally hopeless teeth (PHT). METHODS: The present authors recruited 22 patients with stage III/IV periodontitis who suffered drifting of the maxillary anterior teeth, with a total of 25 teeth. The PHT were extracted for in vitro root canal treatment (RCT). The root surface was smoothed and the shape was trimmed, and the alveolar socket was scratched. The dental implant system was used to prepare the alveolar socket according to the direction, depth and shape of the tooth implantation. The PHT were reimplanted into the prepared alveolar socket. The periodontal indicators were analysed statistically before and after surgery. RESULT: Twenty-two patients who completed the full course of treatment, with a total of 25 PHT, had a successful retention rate of 88%. Mean periodontal probing depth (PPD) decreased by 2.880 ± 0.556 mm and 3.390 ± 0.634 mm at 6 months and 1 year, respectively, and clinical attachment loss (CAL) decreased by 2.600 ± 0.622 mm and 2.959 ± 0.731 mm at the same time points, respectively, showing significant improvement (P < 0.05). CONCLUSION: Dental implant system-assisted IR can effectively preserve "drifted" natural PHT in patients with stage III/IV periodontitis.

How effective is dentin autograft for socket preservation and implant site preparation: A systematic review protocol.

Background: Socket preservation is a surgical procedure aimed at preserving the dimensions of the alveolar bone following tooth extraction. It is performed by filling the extraction socket with bone graft material with or without a barrier membrane. Recently, dentine obtained from extracted teeth has been tried as an autograft for socket preservation. Studies have compared the use of dentin to other bone grafts, however, systematic reviews evaluating the efficacy of dentin for socket preservation are limited. Hence, this systematic review protocol is proposed to generate evidence on the efficacy of dentin as a viable alternative to other bone graft materials for socket preservation. Methods: This systematic review protocol was prepared according to the Methodological Expectations of the Cochrane Intervention Reviews (MECIR) guidelines. It will be conducted using the Cochrane Handbook for Systematic Review of Interventions. PubMed, Scopus, Web of Science, EMBASE, Epistemonikos, Cochrane Central, and EBSCO databases and clinical trial registries, will be searched for all randomized controlled trials (RCTs) and non-randomized studies that have used autologous dentin graft (either in particulate/putty, or/matrix form) for socket preservation. The radiographic and clinical assessment of bone and soft tissue healing of the preserved sockets along with patient-related outcomes following surgery will be assessed. The risk of bias assessment of the RCTs and Non-RCTs will be assessed using the 'Cochrane Risk of Bias assessment tool (ROB II) and ROBINS-I respectively. The certainty of evidence will be assessed by the GRADE approach. Discussion: This evidence is important for dental clinicians and the public to make an informed decision when choosing graft material for socket preservation. The extracted teeth are considered biological waste; however, this evidence provides scope for using a less invasive autograft for bone regenerative procedures. Systematic review registration: PROSPERO: CRD42021201958 (Registered on 15/02/2021).

Eggshell membrane as a regenerative material in alveolar bone grafting in combination with advanced platelet rich fibrin.

Abstract: The eggshell and the eggshell membrane (ESM) are significant by-products of the poultry industry and are being utilized for various valuable purposes in health care, like soft tissue healing and pain alleviation. The aim and objective of our study are to assess the effect of the eggshell membrane on alveolar bone regeneration after tooth extraction. A total of 40 extraction sockets (bilateral) among 20 patients were assessed clinically for healing, and radiographic parameters of bone density and socket volume were assessed on CBCT at baseline, 3 months, and 6 months. Advanced platelet-rich fibrin was created from 5 ml of autologous blood from the patient and centrifuged for 15 minutes at 1500 RPM/168 RCF. The commercially available powdered form of egg shell membrane was used in the study. Based on the randomized allotment (coin-flip), A-PRF alone or A-PRF mixed with eggshell membrane was placed inside the extraction socket and was stabilized using 3-0 silk sutures. It was ob-served that wound healing was uneventful in all 20 patients. No evidence of dry sockets or allergic reactions was noted in any patient. Statistical analysis was done using the un-paired t-test and Mann-Whitney U test with SPSS version 20.0. P<0.05 was considered significant. On comparison of the mean bone density at baseline, 3 months, and 6 months, the socket density in the eggshell with the PRF group was higher compared to the control group. To conclude, eggshell membrane has good regenerative properties and excellent osteogenic capacity; therefore, it could be a useful graft due to its low cost, abundant availability, and simple application.

Feasibility and Preliminary Efficacy of α-Calcium Sulfate Hemihydrate in Socket Preservation: Protocol for a Pilot Randomized Controlled Trial.

BACKGROUND: Tooth extraction procedures often lead to bone resorption, which can have adverse effects on the dimensions of the alveolar ridge. Research has shown that socket preservation techniques using bone graft substitutes can effectively minimize early bone loss in such cases. α-calcium sulfate hemihydrate (α-CSH) has garnered significant attention as a potential bone graft material due to its favorable properties, including osteoconductivity, angiogenic potential, and biocompatibility. Considering these facts, we developed a preliminary protocol for applying α-CSH in addressing alveolar bone loss following tooth extraction. OBJECTIVE: This research's general objective is to evaluate the feasibility and initial effectiveness of α-CSH as bone-inducing graft material for socket preservation after tooth extraction. METHODS: This preliminary clinical trial will involve 30 fresh extraction sockets from individuals aged 18-35 years. The participants will be divided into 2 groups: one group will receive α-CSH graft material after tooth extraction for socket preservation, while the other group will not receive any graft material. Throughout the study, the participants will be closely monitored for safety measures, which will include clinical examinations, radiographic imaging, and blood tests. Radiographic imaging will be used extensively to assist the progress of bone formation. RESULTS: The study commenced enrollment in August 2022 and is scheduled to conclude post assessments and analyses by the end of 2023. The results of the study are anticipated to be accessible in late 2024. CONCLUSIONS: This clinical study represents the initial investigation in humans to assess the feasibility and efficacy of α-CSH in alveolar bone regeneration. We hypothesize that the inclusion of α-CSH can greatly expedite the process of bone formation within fresh sockets, resulting in a swift restoration of bone height without the disadvantages associated with harvesting autogenous bone graft. TRIAL REGISTRATION: Indonesia Registry Center INA-D02FAHP; https://tinyurl.com/2jnf6n3s. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49922.

Concentrated growth factor and collagen as barrier materials in alveolar ridge preservation for posterior teeth: a prospective cohort study with one-year follow-up.

OBJECTIVES: This study aims to evaluate the efficacy of concentrated growth factor (CGF) membrane and collagen as barrier materials in sealing the alveolar socket in alveolar ridge preservation (ARP) in the posterior region during a one-year follow-up. METHODS: A total of 24 patients who underwent ARP in the posterior region were selected for inclusion and randomly assigned to the CGF group (12 cases) and Collagen group (12 cases). The patients in both groups underwent extraction of posterior teeth. The extraction sockets were filled with a bone substitute to the level of the pre-extraction buccal and lingual or palatal alveolar bone plates. The wounds in the CGF group were closed with a fabricated CGF overlaying the upper edge of the bone substitute material, whereas those in the Collagen group were closed with Bio-Oss Collagen. The implants were placed after 6 months. The evaluation was based on implant retention, re-grafting rate, and vertical and horizontal alveolar ridge bone volume changes measured by cone beam computed tomography (CBCT). Data were statistically analyzed using SPSS 28.0 software. RESULTS: No patient withdrew throughout the follow-up period. No implant failure and no severe peri-implant or mucosal soft tissue complications were observed. Six months after the operation, the degree of vertical alveolar ridge height resorption in the CGF group was lower than that in the Collagen group (P<0.05). There were no statistically difference between the groups at 1 year after the operation (P>0.05). The amount of bone reduction in horizontal alveolar ridge width showed no difference between the groups at 6 months and 1 year after surgery (P>0.05). CONCLUSIONS: CGF membrane and Bio-Oss Collagen as barrier materials for posterior ARP inhibited reduction in alveolar ridge bone mass.

Use of autologous tooth-derived material as a graft in the post-extraction socket. Split-mouth study with radiological and histological analysis.

BACKGROUND: The healing process after tooth removal involves bone remodelling which implies some loss of alveolar bone volume. Among materials proposed for minimising this remodelling and preserving the bone, autologous dental tissue is a promising option, but more data are needed. In this context, we evaluated size and density changes using cone beam computed tomography in autologous dental material (ADM)-preserved sockets compared to controls, and assessed biological responses by histological analysis. METHODS: A split-mouth study was conducted including 22 patients, who underwent removal of ≥ 2 single-rooted teeth with intact sockets, assigning one socket to the experimental group which received ADM for alveolar preservation and another to the control group, which only underwent blood clot stabilisation. Cone beam computed tomography was performed postoperatively (week 0) and at weeks 8 and 16 to assess socket size and bone density. Histological analysis was carried out on trephine biopsies taken (Ø4 × 4.5 mm) from the experimental group. RESULTS: Less horizontal shrinkage was observed in the ADM group, especially at week 16 considering the group-by-time interaction for the following variables: difference in height between the lingual and buccal alveolar crests (-1.00; p < .01; 95% CI: -0.28 - -1.73), and half-widths, measured as the distance from the long axis of the missing tooth to the buccal alveolar crest at 1 mm (-0.61; p < .01; 95% CI: -0.18 - -1.04) and at 3 mm (-0.56; p < .01; 95% CI: -0.15 - -0.97) below the crest, with mean decreases of 1.07 and 2.14 mm in height difference, 0.66 and 1.32 mm in half-width at 1 mm and 0.43 and 1.02 mm in half-width at 3 mm in ADM and control groups respectively. Densitometry analysis showed higher bone densities in Hounsfield units in the ADM group considering all factors analysed regardless of time point and socket third (coronal, middle, or apical). Histologically, there were no signs of inflammation or foreign body reaction, and dentin particles were surrounded by and in close contact with bone tissue. CONCLUSION: These results add to the evidence that dentin can be used successfully as a material for alveolar socket preservation, given its desirable mechanical and biological properties, and warrant larger studies.

Selective Preservation of Tooth (SPOT): A Step-by-Step Protocol for a Precise, Reproducible, Socket-Shield Technique.

The socket-shield technique is a clinical procedure aimed at preventing both hard- and soft-tissue collapse following immediate implant placement. The technique can be challenging as multiple factors influence the precision of this treatment. Selective preservation of tooth (SPOT) is a standardized, reproducible tooth-guided preparation protocol for achieving a socket shield and for immediate post-extraction implant site preparation and placement. SPOT emphasizes the utilization of osseodensification burs in both forward (ie, clockwise) rotation, to allow for simultaneous precise root apex removal and shield preparation, and reverse (ie, counterclockwise) rotation, to allow for implant site preparation with further compaction-autografting of bone and dentin, thereby improving implant primary stability and its subsequent early healing. This article presents SPOT in a step-by-step protocol for socket-shield and implant site preparation with immediate post-extraction implant placement. The article describes the stepwise application for single-rooted teeth.

Reconstruction of Sockets and Associated Maxillary Ridge Defect Using Suture Tenting, Synthetic Bone Graft, and Unique Macro Morphology Implants With an Immediately Loaded Provisional Bridge.

Immediate implant placement in the anterior maxilla remains complex, particularly when the labial cortical plate of the socket is deficient and there is an associated class IV ridge defect with both hard- and soft-tissue deficiencies. This case report describes a novel combination of polydioxanone (PDS) suture tenting to support a synthetic bone graft with simultaneous implant placement with implants featuring a body-shift design and subcrestal internal angle correction. In addition, the implants were immediately loaded with a four-unit provisional bridge at the time of surgery, thus reducing morbidity, costs, and total treatment time.

Guidelines for Immediate Vs Delayed Dental Implant Placement in the Esthetic Zone.

The placement of immediate dental implants in the esthetic zone is a highly successful procedure, however it requires careful case selection. Depending on the structural integrity of the alveolar socket and the gingival level, either an implant can be placed immediately and provisionalized or its insertion may need to be delayed. If the extraction site is compromised, implant placement should be deferred to allow bone or soft-tissue grafting or a combination of both to facilitate esthetic implant placement. In addition, two other treatment factors need to be considered with regard to immediate placement: (1) if the implant has low primary stability (ie, low insertion torque value), a custom healing abutment should be fabricated to maintain tissue contour and retain bone placed into the buccal gap; (2) if there is high primary stability (ie, high insertion torque value), fabrication of an immediate fixed provisional will preserve tissue contour, hold a buccal gap bone graft in place, and provide an esthetic result. At sites where the implant will be placed, factors favoring immediate placement include the following: coronal position of the gingiva compared to adjacent teeth, a type I socket classification, and class I or II sagittal root position. The purpose of this article is to present clinical guidelines that can aid in the decision-making process for delayed versus immediate implant placement.

Clinical and radiographic outcomes of a two-piece ceramic implant: one year results from a prospective clinical trial.

OBJECTIVE: To describe the clinical and radiographic performance and survival rate of a new two-piece ceramic implant system after at least 12 months of follow-up. MATERIALS AND METHODS: Sixty-five implants were placed and followed up for at least 12 months (12.3 ± 1.5), in 50 patients. The implants were installed both in fresh extraction sockets and in healed sites and received provisional restoration when the clinical insertion torque was greater than 35Ncm. The primary results describe the survival rate of these implants. Clinical performance was evaluated through the evaluation of the Pink Esthetic Score (PES) and the degree of satisfaction of the patients. Bone loss was measured through radiographic measurements of the marginal bone loss in the mesial (MBLM) and distal (MBLD) sites. RESULTS: The survival rate was 98.5%. The average MBLM was 0.24 mm (± 0.53) and the MBLD was 0.27 mm (± 0.57). A statistical difference was observed only when comparing immediate implants with delayed ones (MBLM - p = 0.046 and MBLD - p = 0.028) and when they received immediate provisionalization or not (MBLM - p = 0.009 and MBLD - p = 0.040). The PES before the intervention (T0) was 13.4 (± 0.8) and the PES at T2 (12-month follow-up) was 12.9 (± 1.5) (p = 1.14). CONCLUSION: The new two-piece ceramic implant used in the present study showed predictable and reliable results, similar to those found with titanium implants after one year of follow-up. CLINICAL RELEVANCE: These implants can be used as an alternative to titanium implants in terms of the marginal bone loss and the degree of patient satisfaction.

Ridge Preservation Combined With Open Barrier Membrane Technique in Case of Postextractive Oroantral Communication: A Case Series Retrospective Study.

After dental extraction, a physiological phenomenon of reabsorption of the dentoalveolar process is triggered, especially if periradicular lesions are present, which can sometimes be associated with oroantral communication in the upper posterior maxilla. To investigate a minimally invasive approach, 19 patients undergoing tooth extraction in the posterosuperior maxilla were recruited. All cases presented an oroantral communication with a diameter of 2-5 mm after tooth extraction and the alveolar process and, in some cases, with a partial defect of 1 or more bony walls. In these cases, a single surgical procedure was used to preserve the alveolar ridge using an open barrier technique with an exposed dense polytetrafluoroethylene membrane. The bottom of the extraction socket was filled with a collagen fleece. The residual bone process was reconstructed using a biomaterial based on carbonate-apatite derived from porcine cancellous bone. After 6 months, all patients were recalled and subjected to radiographic control associated with an implant-prosthetic rehabilitation plan. Data relating to the sinus health status and the average height and thickness of the regenerated bone were collected. Radiographic evaluation verified the integrity of the maxillary sinus floor with new bone formation, detecting a vertical bone dimension between 3.1 mm and 7.4 mm (average 5.13 ± 1.15 mm) and a horizontal thickness between 4.2 mm and 9.6 mm (average 6.86 ± 1.55 mm). The goal of this study was to highlight the advantage of managing an oroantral communication and, simultaneously, obtain the preservation and regeneration of the alveolar bone crest. The open barrier technique appears to be effective for the minimally invasive management of oroantral communication up to 5 mm in diameter in postextraction sites, with a good regeneration of hard and soft tissue.

Comparison of Immediate Implantation into the Socket with and without Periapical Pathology: Systematic Review and Meta-Analysis.

Background and Objectives: The present systematic review and meta-analysis were conducted to evaluate and compare the long-term clinical outcomes of immediate implants placed into fresh sockets with and without periapical pathology. Materials and Methods: After the search and review of the literature in the electronic databases, 109 publications were achieved. The titles and abstracts of 66 publications were screened. After the evaluation of the full text of 22 publications, based on the inclusion criteria, six controlled clinical studies were included in this systematic review and meta-analysis. Results: The statistical calculation showed no heterogeneity among the studies included. The implant survival was 99.6% in the test (socket with periapical pathology) and control (socket without periapical pathology) groups of all the clinical trials. The results of the meta-analysis showed no statistically significant difference between test and control groups regarding the marginal bone level and the width of keratinized mucosa in all the studies. Other parameters indicating plaque level, bleeding on probing, and gingival recession also did not differ between test and control groups at the final follow-up in nearly all studies. Conclusions: Within the limitation of this systemic review and meta-analysis, the obtained data suggest that implants immediately placed into the extraction sockets of teeth exhibiting periapical pathology can be successfully osseointegrated for an extended period.

Performance of a multiphase bioactive socket plug with a barrier function for alveolar ridge preservation.

The natural healing process of extraction socket and traditional socket plug material could not prevent buccal bone wall resorption and down growth of epithelium from the socket orifice. A multiphase bioactive socket plug (BP) is designed to overcome the natural healing process by maintaining the three-dimensional (3D) volume of extraction sockets, particularly in sockets with wall defects, and later provide sufficient alveolar bone volume for implant placement. The study aimed to fabricate and evaluate the physical, chemical, and biological performance of BPin vitro. The BP was fabricated through freeze-drying and layer-by-layer assembly, comprised of a base serving as a scaffold, a central portion for promoting bone regeneration, an upper buccal portion for maintaining alveolar socket dimension with a covering collagen membrane (Memb) on the top and upper buccal surface to prevent soft tissue infiltration. The BP as the experimental group and a pure collagen plug (CP) as the control group were investigated and compared. Radiograph, scanning electron microscopy, and energy-dispersive spectroscopy mapping confirmed that the four-part BP was successfully assembled and fabricated. Swelling rate analysis indicated that BP, CP, and Memb reached swelling equilibrium within 1 hour. BP exhibited a high remaining weight percentage in collagenase solution (68.81 ± 2.21% on day 90) and sustained calcium ion release, reaching the maximum 0.13 ± 0.04 mmol l-1on day 14. In biological assays, BP exhibited excellent cell proliferation (The OD value increased from 0.02 on day 1 to 0.23 on day 21.). The BP group exhibited higher alkaline phosphatase activity and osteocalcin content than the CP group within 21 days. Memb and BP exhibited outstanding barrier function, as evidenced by Hematoxylin and eosin staining. In summary, the multiphase bioactive socket plug represents a promising scaffold for alveolar ridge preservation application.

Microbial colonization in the partially exposed nonabsorbable membrane during alveolar ridge preservation.

AIM: This study evaluated the impact of the partial exposition of the nonabsorbable membrane (dPTFE) on microbial colonization during bone healing. MATERIALS AND METHODS: Patients indicated for tooth extraction were randomized to dPTFE group (n = 22) - tooth extraction and alveolar ridge preservation (ARP) using an intentionally exposed dPTFE membrane and USH group (n = 22) - tooth extraction and unassisted socket healing. Biofilm samples were collected at the barrier in the dPTFE and on the natural healing site in the USH after 3 and 28 days. Samples from the inner surface of the dPTFE barrier were also collected (n = 13). The microbiome was evaluated using the Illumina MiSeq system. RESULTS: Beta diversity was different from 3 to 28 days in both groups, and at 28 days, different microbial communities were identified between therapies. The dPTFE was characterized by a higher prevalence and abundance of gram-negative and anaerobic species than USH. Furthermore, the inner surface of the dPTFE membrane was colonized by a different community than the one observed on the outer surface. CONCLUSION: Intentionally exposed dPTFE membrane modulates microbial colonization in the ARP site, creating a more homogeneous and anaerobic community on the inner and outer surfaces of the membrane. CLINICAL RELEVANCE: DPTFE promoted faster biofilm colonization and enrichment of gram-negative and anaerobes close to the regenerated site in the membrane's inner and outer surfaces. dPTFE membrane can be used exposed to the oral site, but approaches for biofilm control should still be considered. The study was retrospectively registered at Clinicaltrials.gov (NCT04329351).

Immediate Loading Using the Digitalized Customized Restoration of Single-tooth Implants Placed in Fresh Extraction Sockets in the Aesthetic Anterior Maxilla: A 10-Year Prospective Study of Marginal Bone Level.

AIM: The objective of this study was to assess marginal bone level around single implants inserted in fresh extraction sockets in the anterior maxillary region and instantly restored with computer-aided design/computer-aided manufacturing customized temporary crowns cemented on the final abutment. MATERIALS AND METHODS: A total of 20 patients (15 females and 5 males, with a mean age of 30 years), where 20 were placed in fresh extraction sockets. After raising a full-thickness flap, atraumatic extraction was performed the implant site was prepared and fixtures were stabilized on the palatal bone wall. The implant location was immediately transmitted to the prepared master model using the pick-up impression coping seated in the surgical guide template. Prefabricated abutments were used as the final abutment on the master model, scanned and the crown was planned using computer-aided manufacturing customized software. Later on 8th weeks, abutments were torqued as per the manufacturer's recommendation, and the final crowns were cemented. Using personalized intraoral radiographs marginal bone level was evaluated mesially and distally to the implant shoulder as a reference at implant placement, 8 weeks, 1, 3, 5, and 10 years after loading. RESULTS: Wholly implants were osteo-integrated positively after 10 years of practical loading, but only 18 were available for clinical and radiological follow-up, and 2 patients with two implants were excluded from the study due to relocation abroad without any implant failure. The average marginal bone loss (MBL) in the current report was 0.16 ± 0.167 mm at crown cementation, 0.275 ± 0.171 mm after 1 year, 0.265 ± 0.171 mm after 3 years, 0.213 ± 0.185 mm after 5 years, and 0.217 ± 0.194 mm at 10 years. CONCLUSION: The strategy of inserting and not removing the final abutment at the time of implant placement facilitates the establishment of adequate attachment of both soft and hard tissues to the abutment surface, ensuring uninterrupted organization of tissue architecture and offers advantages in helping maintain soft tissue maturation and preventing marginal bone level. CLINICAL SIGNIFICANCE: Immediately loaded implants in freshly extracted sockets lead to a significant reduction in marginal ridge resorption. The use of a temporary crown on a prefabricated abutment, exclusive of successive abutment manipulation, proved effective in preserving the primarily founding blood clot and served as a prototype for shaping the soft tissue around the previously wounded gum. How to cite this article: Berberi A, El Zoghbi A, Aad G, et al. Immediate Loading Using the Digitalized Customized Restoration of Single-tooth Implants Placed in Fresh Extraction Sockets in the Aesthetic Anterior Maxilla: A 10-Year Prospective Study of Marginal Bone Level. J Contemp Dent Pract 2024;25(3):213-220.

Dynamic analyses of a soft tissue-implant interface: Biological responses to immediate versus delayed dental implants.

AIM: To qualitatively and quantitatively evaluate the formation and maturation of peri-implant soft tissues around 'immediate' and 'delayed' implants. MATERIALS AND METHODS: Miniaturized titanium implants were placed in either maxillary first molar (mxM1) fresh extraction sockets or healed mxM1 sites in mice. Peri-implant soft tissues were evaluated at multiple timepoints to assess the molecular mechanisms of attachment and the efficacy of the soft tissue as a barrier. A healthy junctional epithelium (JE) served as positive control. RESULTS: No differences were observed in the rate of soft-tissue integration of immediate versus delayed implants; however, overall, mucosal integration took at least twice as long as osseointegration in this model. Qualitative assessment of Vimentin expression over the time course of soft-tissue integration indicated an initially disorganized peri-implant connective tissue envelope that gradually matured with time. Quantitative analyses showed significantly less total collagen in peri-implant connective tissues compared to connective tissue around teeth around implants. Quantitative analyses also showed a gradual increase in expression of hemidesmosomal attachment proteins in the peri-implant epithelium (PIE), which was accompanied by a significant inflammatory marker reduction. CONCLUSIONS: Within the timeframe examined, quantitative analyses showed that connective tissue maturation never reached that observed around teeth. Hemidesmosomal attachment protein expression levels were also significantly reduced compared to those in an intact JE, although quantitative analyses indicated that macrophage density in the peri-implant environment was reduced over time, suggesting an improvement in PIE barrier functions. Perhaps most unexpectedly, maturation of the peri-implant soft tissues was a significantly slower process than osseointegration.

Synchrotron Analysis of Damaged Extraction Sockets Augmented Using a Synthetic Bone Block: A Pilot Study.

This study aimed to investigate the dimensional stability and quality of the alveolar ridge augmented using a synthetic bone block (SBB) at damaged extraction sockets. Four participants were included, and socket augmentation was performed using SBB and a collagen membrane. Intraoral and CBCT scans were performed before extraction (baseline), immediately postoperative (IP), and at 6 months postoperative (6M). At 6M, a trephine biopsy sample was obtained during implant placement, and the sample was observed using synchrotron. Soft tissue profile changes were assessed using profilometric analysis of the intraoral scan data, while dimensional changes in hard tissue were evaluated based on CBCT measurements. Bone quality was analyzed using synchrotron imaging. There were minimal changes in the soft tissue profile between baseline and IP, baseline and 6M, and IP and 6M (0.11 ± 1.08 mm3, 0.02 ± 0.8 mm3, and -0.65 ± 0.82 mm3, respectively). Horizontal bone width was measured at 1-mm increments from the augmented bone crest to 5 mm apically and revealed only a slight reduction (< 1 mm) at all levels between IP and 6M. The augmented bone height was well maintained from IP until 6M (-0.21 ± 0.53 mm). Synchrotron analysis revealed low to moderate bone quality after 6M (percentage of new bone: 16.49% ± 4.91%). Socket augmentation using SBB appears to be a viable technique for regenerating damaged extraction sockets, with the augmented ridge dimensions maintained up to 6M. Further long-term randomized clinical trials are needed.

[Dynamic monitoring and esthetic evaluation of dimensional changes in the peri-implant soft tissue contour after the immediate implant placement and provisionalization with the modified socket-shield technique in the esthetic zone].

Objective: To accurately measure the dynamic changes of peri-implant soft tissue within one year after the immediate implant placement and provisionalization with the modified socket-shield technique (MSST) in the esthetic zone, and to provide a basis for evaluating the effect of the modified socket-shield technique on the maintenance of peri-implant soft tissue. Methods: A total of 22 patients (22 implants) were prospectively included 1 year after completion of immediate implant placement and provisionalization (IIPP) within MSST in the esthetic zone from January 2022 to January 2024 at the Department of Oral Implantology in the Stomatological Hospital of Chongqing Medical University. The intraoral optical models of patients were obtained by an intraoral scanner system preoperatively and at 3, 6, and 12 months postoperatively, respectively. The standard tessellation language files of intraoral optical models at multiple time points were imported to Geomagic Studio 2013 to be superimposed and aligned for analyzing the peri-implant soft tissue contour on the labial side of the implant site at multiple levels. The amount of gingival margin recession, gingival papilla change, and thickness change of the labial side of the soft tissues at each postoperative point in time were measured at each postoperative time point, as well as evaluating the esthetic effect by the pink esthetic score (PES). Results: The patients were (40±13) years old (21-75 years), including 9 males and 13 females. No adverse events occurred in all the implants during the 12-month follow-up period. The recession level of the gingival margin of the implant site (GL) was 0.08 (0.07) mm, the recession level of the mesial papilla (ML) was 0.19 (0.25) mm, and the recession level of the distal papilla (DL) was 0.19 (0.10) mm. The average collapse thickness of the soft tissue contour on the labial side of the implant (ΔD) was (0.39±0.09) mm, mainly occurring within 2 mm of the root of the gingival margin. The height of the alveolar bone was reduced by (0.17±0.08) mm. The thickness of the labial alveolar bone at 1, 3, and 5 mm root side of the implant shoulder was reduced by (0.13±0.08), (0.12±0.10) and 0.04 (0.17) mm, respectively. The postoperative pink esthetic score was 13.00 (2.25) points at 12 months, which suggested that all implant sites achieved ideal esthetic results. Conclusions: The labial soft tissue contour at implant sites shows minimal change following immediate implant placement and provisionalization using the modified socket-shield technique for 1 year in the esthetic zone.

RNA Technology to Regenerate and Repair Alveolar Bone Defects.

microRNA-200a (miR-200a) targets multiple signaling pathways that are involved in osteogenic differentiation and bone development. However, its therapeutic function in osteogenesis and bone regeneration remains unknown. In this study, we use in vitro and in vivo models to investigate the molecular function of miR-200a overexpression and miR-200a inhibition using a plasmid-based miR inhibitor system (PMIS) on osteogenic differentiation and bone regeneration. Inhibition of miR-200a using PMIS-miR-200a significantly increased osteogenic biomarkers of human embryonic palatal mesenchyme cells and promoted bone regeneration in rat tooth socket defects. In rat maxillary M1 molar extractions, the supporting tooth structures were removed with an implant drill to yield a 3-mm defect in the alveolar bone. A collagen sponge was inserted into the open alveolar defect and PMIS-miR-200a plasmid DNA was added to the sponge and the wound sutured to protect the sponge and close the defect. It was important to remove the existing tooth supporting structure, which can influence alveolar bone regeneration. The alveolar bone was regenerated in 4 wk. The collagen sponge acts to stabilize and deliver the PMIS-miR-200a DNA to cells entering the sponge in the bone defect. We show that mesenchymal stem cells expressing CD90 and Stro-1 enter the sponges, take up the DNA, and express PMIS-miR-200a. PMIS-miR-200a initiates a bone regeneration program in transformed cells in vivo. In vitro inhibition of miR-200a was found to upregulate Wnt and BMP signaling activity as well as Runx2, OCN, Lef-1, Msx2, and Dlx5 associated with osteogenesis. Liver and blood toxicity testing of PMIS-miR-200a-treated rats showed no increase in several biomarkers of liver disease. These results demonstrate the therapeutic function of PMIS-miR-200a for rapid bone regeneration. Furthermore, the studies were designed to demonstrate the ease of use of PMIS-miR-200a in solution and applied using a syringe in the clinic through a simple one-time application.