Bone-level Tapered Implants for Single Tooth Replacement. Immediate vs Delayed Placement: A Randomized, Controlled, Multi-center One-year No-inferiority Clinical Study.

MATERIALS AND METHODS: Post-market, prospective, randomized, controlled, multi-center study with a primary endpoint of one year. 53 subjects were randomized to receive either immediate implant placement (test group) or delayed implant placement (control group). The mean crestal bone-level changes from implant loading to 12 months post-implant loading were measured using standardized, digital periapical radiographs. Changes in facial plate thickness measured on cone-beam computed tomography (CBCT) images, implant success and survival, implant stability, soft tissue changes, patient-centered outcomes, and adverse effects were measured to assess outcomes between the test and control treatments at 12 months post-loading. RESULTS: 46 subjects completed the study (23 in each group). Mean bone changes from loading to the 12 month follow-up were recorded with no statistically significant difference (p=0.950) between both groups. The hypothesis was confirmed that immediate implant placement (Test) in extraction sockets is similar to delayed placement (Control). The test group was found to be similar to the control group (P=0.022) in terms of mean changes in facial plate thickness. Implant survival and success were 95.8% in the test group and 92% in the control group. Stability in the control group was superior at the time of surgery, but there was no difference between both groups at implant loading, producing a non-significant p-value of (0.563). CONCLUSION: This randomized, controlled, multi-center one-year study showed comparable outcomes 1-year after prosthetic loading in the immediate and delayed placement groups.

Recruitment strategies and retention rates for five National Dental PBRN studies.

Background: We describe a retrospective assessment of practitioner and patient recruitment strategies, patient retention strategies, and rates for five clinical studies conducted in the National Dental Practice-Based Research Network between 2012 and 2019, and practitioner and patient characteristics associated with retention. Methods: Similar recruitment strategies were adopted in the studies. The characteristics of the practitioners and patients are described. The proportion of patients who either attended a follow-up (FU) assessment or completed an online assessment was calculated. For studies with multiple FU visits or questionnaire assessments, rates for completing each FU were calculated, as were the rates for completing any and for completing all FU assessments. The associations of practitioner and patient characteristics with all clinic FU visits, and with the completion of all assessments for a study were ascertained. Results: Overall, 591 practitioners and 12,159 patients were included. FU rates by patients for any assessment varied from 91% to 96.5%, and rates for participating in all assessments ranged from 68% to 87%. The mean total number of patients each practitioner recruited was 21 (sd = 15); the mean number per study was 13 (sd = 7). For practitioners, practice type and patient enrollment were associated with greater clinic retention, while only race was associated with their patients completing post-visit online assessments. For patients, age was associated with clinic retention, while female gender, age, race, and education were all associated with greater completion of post-visit online assessments. Conclusion: The Network efficiently recruited practitioners and patients and achieved high patient retention rates for the five studies.

Characteristics of dentists in the National Dental Practice-Based Research Network.

OBJECTIVES: Our aims are to describe the characteristics of dentists, members of the US National Dental practice-based research network (PBRN) in the United States, and determine how often these dentists provide specific dental procedures. METHODS: Dentists completed a questionnaire when they enrolled in the Network about their demographic and training characteristics and characteristics of their practices and patients. Dentists also reported the frequency of providing specific dental procedures. Data were analyzed using descriptive statistics. RESULTS: Of 4,483 dentists in active clinical practice, 34% identified as females, 70% as white, and 73% as general dentists. Most dentists practiced in large metropolitan areas (87%) and in solo or small practices (72%). On average, they reported about one-half of their patients were children or older adults, a third were from historically underrepresented racial and ethnic groups, and one-quarter were covered by public insurance. Most dentists routinely performed restorations and fixed prosthetics (78%), extractions (59%), removable (44%) and implant (40%) prosthetics, and endodontics on incisor and premolar teeth (44%). CONCLUSIONS: Dentists participating in the National Dental PBRN have much in common with dentists at large. The network has a broad representation of dentists, practice types, patient populations, and treatments offered, including diversity regarding race/ethnicity, gender, insurance, and geography of its practitioners and patients. CLINICAL SIGNIFICANCE: Characteristics of National Dental PBRN dentists suggest that a broad range of dentists is interested in participating in national-level research studies, thereby enabling an array of clinical study settings and topics that can optimize the generalizability of study findings.

Structure, function, and productivity from the National Dental Practice-Based Research Network.

Introduction: Following inception in 2005 as a multiregional practice-based research network (PBRN), the "National Dental PBRN" expanded nationwide in 2012, and in 2019 implemented additional organizational changes. The objectives are to: (1) describe the new structure and function of the network; and (2) quantify its scientific productivity since 2005. Methods: A national Administrative and Resource Center is based in Alabama; regional and specialty nodes are based in Alabama, Florida, Illinois, Minnesota, Oregon, New York, and Texas. A Network Coordinating Center is based in Oregon. Studies are funded via investigator-initiated grants. Scientific productivity is assessed using specific metrics, including the Relative Citation Ratio. Results: To date, 58 studies have been completed or are in data collection or development. These studies have investigated a broad range of topics using a wide variety of study designs. Of the studies that have completed enrollment, 70,665 patients were enrolled, as were 19,827 practitioners (some participated in multiple studies), plus electronic records for 790,493 patients in two data-only studies. To date, these studies have led to 193 peer-reviewed scientific publications in 62 different journals. The mean (1.40) Relative Citation Ratio of Network publications connotes a greater-than-average influence in their fields. Conclusions: These metrics demonstrate that the PBRN research context can successfully engage practitioners and patients from diverse settings nationally with a high and sustained level of scientific productivity. This infrastructure has enabled clinical scientists in oral health and nonoral health topics and provided additional recruitment venues outside of the typical academic health center research context.

Implications of considering peri-implant bone loss a disease, a narrative review.

BACKGROUND: Peri-implantitis has been suggested to cause significant increasing proportions of implant failure with increasing time. PURPOSE: To assess whether implant failure rates in long term studies are matching the supposed high prevalence of peri-implantitis. MATERIAL AND METHODS: This paper is written as a narrative review of the long-term clinical investigations available in the literature. RESULTS: Some implant systems have seen unacceptable marginal bone loss figures with time coupled to increased implant failure rates, resulting in the withdrawal of these systems. The reasons for such mishap are generally unknown, with the exception of one system failure that was found to be due to improper clinical handling. Modern, moderately rough implant systems have functioned excellently over 10-15 years of follow up with minor problems with marginal bone loss and implant failure rates within a few per cent. Machined implants have functioned adequately over 20-30 years of follow up. Implant failures occur predominantly during the first few years after implant placement. No significant increase of implant failures has been observed thereafter over 20-30 years of follow up. Over the years of our new millennium, scientific and technical advances have allowed the discovery of numerous molecular pathways and cellular interactions between the skeletal and immune system promoting the development of the interdisciplinary field called osteoimmunology. Nowadays, this knowledge has not only allowed the emergence of new etiologic paradigms for bone disease but also a new dynamic approach on the concept of osseointegration and MBL around oral implants, re-evaluating our older disease oriented outlook. This facilitates at the same time the emergence of translational applications with immunological perspectives, scientific approaches based on omics sciences, and the beginning of an era of personalized dental implant therapy to improve the prognosis of oral implant treatment. CONCLUSIONS: Oral implant systems have been found to function with very good clinical outcome over follow-up times of 20-30 years. Registered implant failures have occurred predominantly during the first few years after implantation, and there has been no significant increase in late failures due to peri-implantitis.

Twelve-month evaluation of a novel mineral-organic adhesive material used to stabilize dental implants placed in oversized osteotomies in vivo in an animal model.

OBJECTIVES: The aim of this study is to evaluate long-term in vivo stability of dental implants stabilized at time of placement in oversized osteotomies with a novel, self-setting, mineral-organic bone adhesive. MATERIALS/METHODS: Canine (26) mandibular teeth were removed, and three oversized osteotomies prepared bilaterally. Implants were placed with either adhesive, particulate xenograft, or with blood clot filling the implant/osteotomy gaps. Removal torque and histology were assessed. RESULTS: The adhesive provided significant and clinically relevant immediate implant stability of 22.2 N-cm (95% CI 5.3; 39.0), which continued throughout the early postoperative course and persisted through the nine- (155 N-cm 95% CI 113; 197) and 12-month (171 N-cm 95% CI 134.2; 209.4) time points. This is in comparison with the blood clot of 1.4 N-cm (95% CI 0.7; 2.1), 128.6 N-cm (95% CI 66.8; 190.4), and 140.7 N-cm (95% CI 78.8; 202.5) and particulate xenograft, 1.3 N-cm (95% CI 0.6; 2.0), 132.1 N-cm (95% CI 94.5; 169.7), and 101.5 (95% CI 59.5; 143.5), respectively. Histological examination shows the adhesive establishes intimate contact with the implant and bony walls and is replaced with new bone without compromising stability. Soft tissue does not penetrate the adhesive, and marginal bone/biomaterial level is maintained. Control sites filled with xenograft or blood clot heal with reduced bone levels, and in some cases, xenograft particles were encapsulated in connective tissue. CONCLUSIONS: Implants placed in oversized osteotomies and lacking primary stability can be stabilized at placement with a novel, highly osteoconductive, and resorbable adhesive. Gradual replacement of the biomaterial allows osseointegration without loss of stability through 12 months of follow-up. This novel adhesive has the potential to stabilize implants placed in sites with inadequate bony support.

Radiographic evaluation of a novel bone adhesive for maintenance of crestal bone around implants in canine oversized osteotomies.

BACKGROUND: A novel bone adhesive (tetracalcium phosphate and O-phospho-L-serine) has been developed as an osteoconductive, biodegradable bone-adherent material. The purpose of this study was to evaluate the maintenance of crestal bone/material level by standardized radiographs. METHODS: This was a randomized, controlled, three arm, prospective study. Twenty-six mixed breed hound dogs were included in this study. Three implants were placed on either side of the mandible with either bone adhesive (BA), bovine bone mineral (BBM), or no biomaterial (negative control [NC]). Standardized periapical radiographs were taken immediately after implant placement and at every month up to 1 year. The vertical distance between the implant platform to the first radiopaque material on both the mesial and distal surfaces were measured and crestal bone/material level changes were analyzed. RESULTS: The crestal bone/material level adjacent to BA was stable and maintained throughout the study. There were statistically significant differences found between BA and NC in terms of maintenance of crestal bone levels at any given timepoint. CONCLUSION: This study demonstrated that BA maintained crestal bone levels and had a similar ability to maintain that level over 1 year compared with BBM.

Risk assessment of labial bone perforation in the anterior mandibular region: a virtual immediate implant placement study.

BACKGROUND: This study investigated the prevalence of labial bone perforation (LBP) related to the associated anatomic factors in anterior mandibular region using a virtual immediate implant placement procedure. METHODS: Series qualified CBCT images of 149 participants (894 teeth) were selected to analyze the assigned anatomical parameters, including concavity depth, concavity angle, torque, and deep bone thickness. Four classes of crestal and radicular dentoalveolar bone phenotypes (CRDAPs) of mandibular anterior teeth were categorized according to the thickness of dentoalveolar bone at both crestal and radicular zones. Data were adjusted for categorical (gender and CRDAP) and continuous (age, cavity angle, cavity depth, and deep bone thickness) variables using a multivariable logistic regression analysis with generalized estimating equation method. RESULTS: The overall probability of LBP after virtual implant placement was 21.6%. There is statistically significant higher prevalence of LBP at canine (28.5%) and CRDAP class II (29.2%) regions (p < 0.001). After adjusting confounding variables, CRDAP class II and class IV regions are more likely to have LBP when compared with CRDAP class I (control) regions (p < 0.01). The risk of LBP at canine site is 6.31 times more likely than at the central incisor (control) (p < 0.01). CONCLUSIONS: Using a virtual immediate implant placement technique, the prevalence of LBP is significantly higher at the mandibular canine site and thin radicular dentoalveolar phenotype in the anterior mandibular region.

Regeneration of critical-sized mandibular defect using a 3D-printed hydroxyapatite-based scaffold: An exploratory study.

BACKGROUND: Three-dimensional (3D) printing has become an available technology to fabricate customized tissue engineering scaffolds with delicate architecture. This exploratory study aimed to evaluate the potential of a 3D-printed hydroxyapatite-based scaffold as a biomaterial for obtaining guided bone regeneration (GBR) in vivo. METHODS: Scaffolds composed of 90% hydroxyapatite and 10% poly(lactic-co-glycolic acid) were printed using a microextrusion process to fit 4 mm diameter and 0.5 mm thick through-and-through osseous defects on the mandibular ramus of rats, with unfilled defects serving as controls. Specimens were analyzed for regeneration-associated gene expression on day 7, and micro-computed tomography (micro-CT) and histology assessments were carried out on day 28. RESULTS: The scaffolds were 3.56 ± 0.43 mm (x-axis) and 4.02 ± 0.44 mm (y-axis) in diameter and 0.542 ± 0.035 mm thick (z-axis), with a mean pore size of 0.420 ± 0.028 × 0.328 ± 0.005 mm2 . Most scaffolds fit the defects well. Type I collagen, VEGF, and Cbfa1 were upregulated in the scaffold-treated defects by day 7. By day 28, de novo osteogenesis and scaffold-tissue integration were evident in the scaffold-treated defects, and entire mineralized tissue, as well as newly formed bone, was significantly promoted, as seen in the micro-CT and histologic analyses. CONCLUSION: The 3D-printed hydroxyapatite-based scaffold showed acceptable dimensional stability and demonstrated favorable osteoregenerative capability that fulfilled the need for GBR.

Preclinical evaluation of a 3D-printed hydroxyapatite/poly(lactic-co-glycolic acid) scaffold for ridge augmentation.

BACKGROUND/PURPOSE: Supracrestal ridge augmentation (SRA) is a major challenge for clinicians. This study investigated the efficacy of a 3D-printed (3DP) hydroxyapatite/poly(lactic-co-glycolic acid) (HA/PLGA) scaffold as a potential biologic for SRA. METHODS: Scaffolds that were 5 mm in diameter and 2.5-mm thick with a 1.2-mm diameter through-and-through central hole composed of 90% HA and 10% PLGA were printed using an extrusion-based bioprinter. The HA/PLGA scaffold was fixed with a 1.2-mm titanium mini-implant on the buccal surface of rat mandible (Ti-HPS), and the outcome of SRA were compared with sites treated with a titanium mini-implant alone (control) and a titanium mini-implant covered with deproteinized bovine bone-derived matrix (Ti-DBBM) at 4 and 8 weeks by microcomputed tomography (micro-CT), back-scattered SEM, and histology assessments. RESULTS: The HA/PLGA scaffolds were 2.486 ± 0.082 mm thick with an outer diameter of 4.543 ± 0.057 mm and an inner diameter of 1.089 ± 0.045 mm, and the pore dimensions were 0.48-0.52 mm. There was significantly more mineralized tissue in the Ti-DBBM and Ti-HPS groups than in the control group at both time points. Newly formed bone (NB) was well-integrated with the DBBM and HA/PLGA scaffolds. The framework of the 3DP-HA/PLGA scaffold remained in place, and NB-implant contact (NBIC) was advanced to the middle level in the Ti-HPS group until 8 weeks, whereas dispersion of DBBM with a lower level NBIC was noted in the Ti-DBBM group at both time points. CONCLUSION: The 3DP HA/PLGA scaffold maintains supracrestal space and demonstrates osteoconductivity to facilitate SRA.

Citation Characteristics of H-Classics Articles in Implant Dentistry: A Citation Analysis Using H-Classics Method.

PURPOSE: Citation-based metrics, such as the H-classics method, have been used as an indicator to assess academic performance in the scientific community. However, information addressing issues regarding self-citation, citation half-life, and subject area of origin in implant dentistry is lacking. The purpose of this study was to investigate the citation characteristics of H-classics articles in implant dentistry throughout different time periods. MATERIALS AND METHODS: H-classics implant dentistry articles were searched and selected by applying the H-classics method from the Scopus database. Bibliometric analysis was conducted to evaluate the citation characteristics, including institutional and journal self-citation, citation half-life, and subject area of origin of identified H-classics articles. RESULTS: The International Journal of Oral & Maxillofacial Implants and Clinical Oral Implants Research are the leading journals contributing the majority of citations to the retrieved H-classics articles. Articles published in the United States cited the most H-classics articles. Journal self-citation was 12.41% on average, while institutional self-citation was approximately 7.81%. Citation half-life decreased significantly across time periods, with an average decreasing ratio of 43.95%. Research on Scope III, bioengineering interventions, had the most prominent distribution citation frequency in the subject area "Others." CONCLUSION: This study provides insightful views regarding citation characteristics of H-classics articles in implant dentistry (eg, interdisciplinary publications on bioengineering interventions) during the investigation periods, which may foster the translation of preclinical research into clinical applications in the future.

Practitioner Engagement in Activities of the National Dental Practice-Based Research Network (PBRN): 7-Year Results.

PURPOSE: To 1) quantify practitioner activities of the National Dental Practice-Based Research Network (Network) for which Continuing Education (CE) credits were received (study training, videos, webinars, meetings, and symposia); 2) quantify practitioner coauthoring Network publications and presentations; and 3) test whether practitioner characteristics were associated with participation in these activities. METHODS: A retrospective analysis of 4361 practitioners who enrolled in the Network between April 12, 2012 and October 12, 2018. RESULTS: Overall, 59% (n = 2586) of practitioners earned CE credit from the Network; among these, 68% (n = 1757) from a video, 38% (n = 993) attended an annual Network meeting, 31% (n = 798) due to training for a Network clinical study, 9% (n = 226) attended a national symposium, and 7% (n = 170) participated in a Network webinar. Members of 2 large group practices earned on average more CEs than practitioners from other practice settings. Four percent (n = 159) of practitioners coauthored a Network presentation or publication. Practitioners who received their dental degree before 2000, were general practitioners, or were members of 2 large group practices, were more likely to have coauthored a publication or presentation. CONCLUSION: This Network used a broad range of activities to engage community practitioners. These activities were successful in sustaining a high level of practitioner engagement in clinical research and its relevance to everyday clinical practice.

Synthesis and Characterization of Melatonin-Loaded Chitosan Microparticles Promote Differentiation and Mineralization in Preosteoblastic Cells.

In terms of a novel scaffold with well good osteoinductive and osteoconductive capacity, melatonin (Mel) possesses positive effects on chemical linkage in scaffold structures, which may allow osteogenic differentiation. The aim of this study is to fabricate Mel-loaded chitosan (CS) microparticles (MPs) as a novel bone substitute through generating a Mel sustained release system from Mel-loaded CS MPs and evaluating its effect on the osteogenic capacity of MC3T3-E1 in vitro. The physical-chemical characteristics of the prepared CS MPs were examined by both Fourier transform infrared spectroscopy and scanning electron microscopy. The released profile and kinetics of Mel from MPs were quantified, and the bioactivity of the released Mel on preosteoblastic MC3T3-E1 cells was characterized in vitro. An in vitro drug release assay has shown high encapsulation efficiency and sustained release of Mel over the investigation period. In an osteogenesis assay, Mel-loaded CS MPs have significantly enhanced alkaline phosphatase (ALP) mRNA expression and ALP activity compared with the control group. Meanwhile, the osteoblast-specific differentiation genes, including runt related transcription factor 2 (Runx2), bone morphogentic protein-2 (Bmp2), collagen I (Col I), and osteocalcin (Ocn), were also significantly upregulated. Furthermore, quantificational alizarin red-based assay demonstrated that Mel-loaded CS MPs notably enhanced the calcium deposit of MC3T3-E1 compared with controls. In essence, Mel-loaded CS MPs can control the release of Mel for a period of time to accelerate osteogenic differentiation of preosteoblast cells in vitro.

Harnessing Omics Sciences and Biotechnologies in Understanding Osseointegration- Personalized Dental Implant Therapy.

A number of significant advances (omics and bioengineering) now enable seamless stratification of patients according to their individual genotypes. This allows for more precise diagnoses coupled with patient phenotypes and improved treatment planning and predictable outcomes. Collectively, these advances are designated as "personalized dental medicine." To become an essential part of personalized dental medicine, this term will have a robust impact on dental implant practice. This narrative review elucidates the importance of utilizing advanced bioengineering techniques and biotechnologies in the realm of dental implants, aiming to understand gene expression profiles controlling endosseous wound healing and promoting bone formation. Thus, the first objective of the review was to present the state of the art of conceptualizing osseointegration as a phenomenon. The second objective was to pave the way for personalized dental implant therapy and to introduce "implantogenomics" for the first time.

Compression-Resistant Polymer/Ceramic Composite Scaffolds Augmented with rhBMP-2 Promote New Bone Formation in a Nonhuman Primate Mandibular Ridge Augmentation Model.

PURPOSE: This study was designed to test the hypothesis that compression-resistant (CR) scaffolds augmented with recombinant human bone morphogenetic protein-2 (rhBMP-2) at clinically relevant doses in a nonhuman primate lateral ridge augmentation model enhances bone formation in a dose-responsive manner without additional protective membranes. MATERIALS AND METHODS: Defects (15 mm long × 8 mm wide × 5 mm deep) were created bilaterally in the mandibles of nine hamadryas baboons. The defect sites were implanted with poly(ester urethane) (PEUR)/ceramic CR scaffolds augmented with 0 mg/mL rhBMP-2 (CR control), 0.75 mg/mL rhBMP-2 (CR-L), or 1.5 mg/mL rhBMP-2 (CR-H). The primary outcome of ridge width and secondary outcomes of new bone formation, cellular infiltration, and integration with host bone were evaluated using histology, histomorphometry, and microcomputed tomography (micro-CT) at 16 weeks following implantation. RESULTS: New bone formation in the mandible was observed in a dose-responsive manner. CR-H promoted significantly greater new bone formation compared with the CR control group. In all groups, ridge width was maintained without an additional protective membrane. CONCLUSION: CR scaffolds augmented with a clinically relevant dose of rhBMP-2 (1.5 mg/mL) promoted significant new bone formation. These results suggest that a CR PEUR/ceramic composite scaffold without a protective membrane may be a potential new rhBMP-2 carrier for clinical use.

Crestal bone response to loaded zirconia and titanium implants: a radiographic and histometric analysis in canines.

OBJECTIVES: To evaluate the crestal bone response to a two-piece zirconia implant compared with a control titanium implant using periapical radiographs (PAs) and histometry. MATERIALS AND METHODS: Thirty zirconia and 30 titanium implants were placed in healed posterior mandibles of five canines. Full-ceramic single-tooth restorations were cemented after 6 weeks of healing. Three observers measured the distance between the implant shoulder and the crestal bone (DIB) at placement, loading, and harvesting after 4 or 16 weeks in function. The influence of implant material and loading time on DIB as well as the inter-observer agreement were analyzed. Additionally, histometric distance between implant shoulder and most coronal bone-to-implant contact (IS-cBIC) was compared with DIB. RESULTS: Mean DIB values increased between 4 and 16 weeks of loading for both zirconia (from 1.66 to 2.25 mm; P < 0.0001) and titanium (from 1.81 to 1.95 mm; P = 0.06). Zirconia yielded mean IS-cBIC values of 2.18 mm and 2.48 mm (P < 0.001) and titanium 2.23 mm and 2.34 mm (P = 0.27) after 4 and 16 weeks, respectively. The raters reached an excellent intraclass correlation coefficient. PAs underestimated the bone loss on average by 0.39 mm. CONCLUSIONS: Zirconia implants showed a greater increase of DIB during early healing and function than titanium. CLINICAL RELEVANCE: Crestal peri-implant tissue dimensions may show more pronounced changes around two-piece zirconia implants during early healing. PAs may underestimate peri-implant bone loss.

Immediate Dental Implant Stabilization in a Canine Model Using a Novel Mineral-Organic Adhesive: 4-Month Results.

PURPOSE: This study evaluated a novel injectable, self-setting, osteoconductive, resorbable adhesive that provides immediate implant stabilization. MATERIALS AND METHODS: Twenty-six large canines had the mandibular second through fourth premolars and the first molar removed bilaterally. After 3 months, oversized osteotomies were prepared with only the apical 2 mm of the implant engaging native bone. One site had a novel resorbable, self-setting, mineral-organic adhesive (TN-SM) placed around the implant, a second site received bone graft, and a third site received only blood clot. Removal torque, standardized radiography, and histology were used to evaluate implant stability and tissue contact after 24 hours, 10 days, and 4 months. RESULTS: Mean removal torque values after 24 hours were 1.4, 1.3, and 22.2 Ncm for the control, bone graft, and mineral-organic adhesive, respectively. After 10 days, these values were 5.7, 6.2, and 45.7 Ncm and at 4 months increased to 88.7, 77.8, and 104.7 Ncm, respectively. Clinical, radiographic, and histologic evaluations showed a lack of inflammatory reaction. Control defects were initially radiolucent in the coronal area; grafted sites revealed particles in the gap, with both conditions gradually filling with bone over time. At 10 days, histologic evaluation demonstrated excellent biocompatibility and intimate contact of mineral-organic adhesive to both the implant and bone, providing an osseointegration-like bond; control sites revealed no bone contact in the defect area, while the bone-grafted sites revealed unattached graft particles. At 4 months, much of the mineral-organic adhesive was replaced with bone; the control and grafted sites had some bone fill, and many of the defects demonstrated no bone-to-implant contact and were filled with soft tissue or isolated graft particles. CONCLUSION: The mineral-organic adhesive provides immediate (osseointegration-like) and continued implant stabilization over 4 months in sites lacking primary stability. Experimental sites demonstrated maintenance of crestal bone levels adjacent to the mineral-organic adhesive and soft tissue exclusion without the use of membranes in this canine model. These results demonstrate that this novel mineral-organic adhesive can enable implant osseointegration in a site where insufficient native bone exists to allow immediate implant placement.

Hard and soft tissue evaluation of titanium dental implants and abutments with nanotubes in canines.

BACKGROUND: Little is known regarding the interaction of dental implant surface nanotubes and oral soft and hard tissues. The purpose of this study was to evaluate both histologically and radiographically the qualitative and quantitative effects of dental implant surface nanotubes on hard and soft tissue in a canine model. METHODS: Three subgroups consisting of a combination of test and control implants and abutments (Group A: control implant/control abutment, Group B: control implant/test abutment: Group C: test implant/test abutment) were placed in edentulous mandibles of six large-breed canines. Implants and abutments were placed on one side at baseline, and on the opposite side of the mandible at week 10; sacrifice occurred at week 12. Quantitative and qualitative analyses were used to measure newly formed hard and soft tissues histologically and radiographically. RESULTS: The mean radiographic change in marginal bone level from weeks 0 to 12 between implant groups was not statistically significant (P > 0.05). Mean soft tissue contact (junctional epithelium + connective tissue) for Groups A, B, and C were 2.29, 2.33, and 2.31 mm, respectively, with no statistically significant difference (P > 0.05) between the groups. All connective tissue fibers were oriented parallel to the abutment regardless of surface treatment. CONCLUSIONS: The findings of this study suggest that healing of hard and soft tissues around implants and abutments is similar when comparing grit-blasted surfaces to machined, turned surfaces with nanotubes. Both resulted in similar soft tissue contact values, as well as connective tissue fiber orientation.

Esthetic, clinical, and radiographic outcomes of two surgical approaches for single implant in the esthetic area: 1-year results of a randomized controlled trial with parallel design.

AIM: The objectives of this study were to compare (a) esthetic, (b) clinical, (c) radiographic, and (d) patient-centered outcomes following immediate (Type 1) and early implant placement (Type 2). MATERIAL AND METHODS: Forty-six subjects needing a single extraction (premolar to premolar) were randomly allocated to Type 1 or Type 2 implant placement. One year following permanent restoration, evaluation of (a) Esthetics using soft tissue positions, and the pink and white esthetic scores (PES/WES), (b) Clinical performance using probing depth, modified plaque index, and sulcus bleeding index (c) Radiographic bone level, and (d) Patient satisfaction by means of visual analogue scales (VAS) was recorded. RESULTS: Thirty-five patients completed the one-year examination (Type 1, n = 20; Type 2, n = 15). Type 1 implants lost 1.03 ± 0.24 mm (mean ± SE) of mid-facial soft tissue height while Type 2 implants lost 1.37 ± 0.28 mm (p = 0.17). The papillae height on the mesial and distal was reduced about 1 mm following both procedures. Frequency of clinical acceptability as defined by PES ≥ 6 (Type 1: 55% vs. Type 2 40%), WES ≥ 6 (Type 1: 45% vs. Type 2 27%) was not significantly different between groups (p > 0.05). Clinical and radiographic were indicative of peri-implant health. Patient-centered outcomes failed to demonstrate significant differences between the two cohorts. CONCLUSION: One year after final restoration, there were no significant differences in esthetic, clinical, radiographic, and patient-centered outcomes following Type 1 and Type 2 implant placement. At one year, patient satisfaction may be achieved irrespective of the two placement protocols.