Oral health-related quality of life (OHRQoL) and implant therapy: A prospective multicenter study of preoperative, intermediate, and posttreatment assessment.

The purpose of this multicenter continuation study was to use high patient numbers in order to generate reliable statements regarding the association between different implant indications and OHRQoL. Patients with various types of indication for dental implants, ranging from single tooth loss to edentulous jaws, were included. Quality of life relating to dental implants was assessed through the oral health impact profile (OHIP-G-21), which has a summary score from 0 to 20 in healthy patients. In total, 16 253 patients from 29 centers (European Centers for Dental Implantology (ECDI)) were involved in the study between 2009 and 2021.8251 patients (50.7%) completed the questionnaire after implant insertion, and 4996 patients (30.7%) after prosthodontic treatment. The average age was 54 years (range 18-88 years). Posterior single-tooth gap (28.5%) and free-end gap (27.8%) were the most frequent indications. The preoperative OHIP-G-21 score for all patients was 32.81 (SD 11.92), while the score during the healing period was 30.00 (SD 10.72), and after completion of treatment 27.24 (SD 9.26) (p < 0.001). The most significant improvements in OHIP-G-21 scores were in the indication of edentulous jaw (phase 1, 41.81 (SD 15.53); phase 2, 35.39 (SD 14.22); phase 3, 29.60 (SD 10.12) (p < 0.001). The study revealed significant improvements in the most frequently reported problems (chewing, serious concerns, appearance) (p < 0.001). Insertion of dental implants and prosthodontic rehabilitation led to an improved OHRQoL for patients with all indications for dental implants. Special attention should be paid to patients with edentulous jaw, since in comparison with other indications it had the greatest impact on improving OHRQoL. The psychological dissatisfaction scale of the OHIP-G-21 represented the most important factors for patients, and these scores were substantially influenced by implant therapy. Thus, treating physicians should increase their focus on these factors, in order to avoid dissatisfaction and increase the likelihood of complete implant therapy success.

Preprosthetic Surgery-Narrative Review and Current Debate.

This review describes the role of modern preprosthetic surgery. The atrophic edentulous jaw can cause severe functional impairment for patients, leading to inadequate denture retention, reduced quality of life, and significant health problems. The aim of preprosthetic surgery is to restore function and form due to tooth loss arising from congenital deformity, trauma, or ablative surgery. Alveolar bone loss is due to disuse atrophy following tooth loss. The advent of dental implants and their ability to preserve bone heralded the modern version of preprosthetic surgery. Their ability to mimic natural teeth has overcome the age-old problem of edentulism and consequent jaw atrophy. Controversies with preprosthetic surgery are discussed: soft tissue versus hard tissue augmentation in the aesthetic zone, bone regeneration versus prosthetic tissue replacement in the anterior maxilla, sinus floor augmentation versus short implants in the posterior maxilla-interpositional bone grafting versus onlay grafts for vertical bone augmentation. Best results for rehabilitation are achieved by the team approach of surgeons, maxillofacial prosthodontists/general dentists, and importantly, informing patients about the available preprosthetic surgical options.

Bone regeneration after maxillary sinus floor augmentation with different ratios of autogenous bone and deproteinized bovine bone mineral an in vivo experimental study.

OBJECTIVE: Test the hypothesis of no difference in bone regeneration after maxillary sinus floor augmentation (MSFA) with different ratios of iliac or mandibular autogenous bone (AB) graft and deproteinized bovine bone mineral (DBBM). MATERIALS AND METHODS: Forty minipigs were randomly allocated to bilateral MSFA using: (A) 100% AB, (B) 75% AB and 25% DBBM, (C) 50% AB and 50% DBBM, (D) 25% AB and 75% DBBM, or (E) 100% DBBM. The animals were euthanized 12 weeks after surgery. Percentage of bone, non-mineralized tissue, and residual DBBM were estimated by histomorphometric analysis in a randomly selected region of interest and summarized as mean percentage with 95% confidence interval (CI). RESULTS: Mean percentage of bone following MSFA with iliac or mandibular AB graft was: (A) 55.5% and 64.2%, (B) 60.3% and 61.6%, (C) 54.4% and 52.1%, (D) 51.8% and 53.1%, and (E) 47.6%, respectively. There was a significant trend toward a higher percentage of bone, with a higher ratio of AB within the graft (p < .01), regardless of the origin of AB graft (iliac or mandible). CONCLUSIONS: The hypothesis was rejected since percentage of bone was significantly increased with larger proportions of AB within the graft. Consequently, AB or a mixture of AB and diminutive quantities of DBBM seem to be the preferred graft for MSFA based solely on histomorphometric assessment. However, it should be emphasized that newly formed bone and residual AB graft particles could not be distinguished by the applied histologic procedure.

Modified Le Fort I interpositional grafting of the severe atrophied maxilla-a retrospective study of 106 patients over 10 years.

OBJECTIVES: The objective of this study was to evaluate a modified Le Fort I interpositional grafting followed by dental implants for the rehabilitation of edentulous atrophied maxillae (Cawood classes IV and V). The surgical modification was a bilateral sinus floor augmentation prior to the osteotomy. This generated a closed recipient bed which allowed the use of particulated bone grafts (xenogenic bone mineral) and a reduced amount of autologous iliac bone grafts. MATERIALS AND METHODS: A total of 106 patients with maxillary interpositional bone grafts were included in this retrospective analysis between 2006 and 2020. The panoramic radiographs and lateral cephalograms were analyzed to assess the gain and stability of the maxillary bone and the peri-implant bone loss. In addition, the observational period of up to 14 years implant survival and success was evaluated. RESULTS: A stable vertical bone height with mean 0.63 ± 1.41 mm resorption over 5 years after implant loading was observed. A mean of 0.20 ± 0.37 mm marginal bone loss was noted after 5 years. The implant survival was 96.4% after 5 years and implant success can be rated 91.7% in a mean follow-up period of 93 months and 168 months maximal observation time. Perioperative complications included sinus membrane perforation (59.43%), wound healing disturbances (25.47%), and transient primary complications (13.78%). All receded apart from two subtotal graft losses (1.8%). CONCLUSIONS: The modified Le Fort I osteotomy with interpositional bone grafts is a predictable procedure in terms of bone and implant stability. Patients with atrophic maxillae who are fit for surgery should be informed about risks and benefits of this treatment alternative.

Prefabricated 3D-Printed Tissue-Engineered Bone for Mandibular Reconstruction: A Preclinical Translational Study in Primate.

The advent of three dimensionally (3D) printed customized bone grafts using different biomaterials has enabled repairs of complex bone defects in various in vivo models. However, studies related to their clinical translations are truly limited. Herein, 3D printed poly(lactic-co-glycolic acid)/ß-tricalcium phosphate (PLGA/TCP) and TCP scaffolds with or without recombinant bone morphogenetic protein -2 (rhBMP-2) coating were utilized to repair primate's large-volume mandibular defects and compared efficacy of prefabricated tissue-engineered bone (PTEB) over direct implantation (without prefabrication). 18F-FDG PET/CT was explored for real-time monitoring of bone regeneration and vascularization. After 3-month's prefabrication, the original 3D-architecture of the PLGA/TCP-BMP scaffold was found to be completely lost, while it was properly maintained in TCP-BMP scaffolds. Besides, there was a remarkable decrease in the PLGA/TCP-BMP scaffold density and increase in TCP-BMP scaffolds density during ectopic (within latissimus dorsi muscle) and orthotopic (within mandibular defect) implantation, indicating regular bone formation with TCP-BMP scaffolds. Notably, PTEB based on TCP-BMP scaffold was successfully fabricated with pronounced effects on bone regeneration and vascularization based on radiographic, 18F-FDG PET/CT, and histological evaluation, suggesting a promising approach toward clinical translation.

Sandwich osteotomy in atrophic mandibles: A retrospective study with a 2- to 144-month follow-up.

OBJECTIVES: The aim of the present retrospective study was to assess the long-term clinical outcome of sandwich osteotomy in pre-implant augmentation of atrophic mandible. MATERIALS AND METHODS: Sandwich osteotomies were performed in partially and fully edentulous mandibles of 63 consecutive patients in the present study. The vertical bone gain, graft stability, and marginal bone loss were measured radiographically. Implant survival and success rates were estimated in the follow-up ranged from 2 to 144 months (mean, 58 months). RESULTS: A total of 75 procedures were reviewed. After an average healing time of 148 days, 220 implants were placed in 74 procedures. Perioperative complications included intraoperative fracture (1/75), transient paresthesia (18/75), wound healing disturbance (18/75), and keratinized tissue deficiency (14/75). The average vertical bone gain was 5.4 mm at the time of implant placement. Significant marginal bone loss occurred during the first 6 months, after which the resorption remained stable. The implant survival rate was estimated as 96.7%, and the success rate was 95.3%. Implant survival and success showed no significant correlation with higher age, anticoagulation therapy, cardiovascular disease, or thyroid disorder. Smoking was correlated with significant lower success rate. CONCLUSION: Sandwich osteotomy is a suitable augmentation procedure for atrophic mandible, allowing for implant placement with promising outcome.

Peri-implantitis and its prevention.

This perspective article on peri-implantitis and its prevention was produced as a supplement to a 3-D, computer-animated film aiming at presenting key characteristics of peri-implant health, the build-up of a biofilm and the ensuing host-response resulting in peri-implant mucositis and, subsequently, peri-implantitis. Treatment concepts for peri-implantitis were briefly reviewed, and prevention of the condition was brought to attention as a priority in implant dentistry. The overview also highlighted the 2017 World Workshop on Classification of Periodontal and Peri-implant diseases and Conditions, in which new disease definitions and case definitions were presented for peri-implant health, peri-implant mucositis, and peri-implantitis.

Current concepts in cleft care: A multicenter analysis.

The current surgical techniques used in cleft repair are well established, but different centers use different approaches. To determine the best treatment for patients, a multi-center comparative study is required. In this study, we surveyed all craniofacial departments registered with the German Society of Maxillofacial Surgery to determine which cleft repair techniques are currently in use. Our findings revealed much variation in cleft repair between different centers. Although most centers did use a two-stage approach, the operative techniques and timing of lip and palate closure were different in every center. This shows that a retrospective comparative analysis of patient outcome between the participating centers is not possible and illustrates the need for prospective comparative studies to establish the optimal technique for reconstructive cleft surgery.

Particulate Coral Hydroxyapatite Sheltered by Titanium Mesh for Localized Alveolar Rehabilitation After Onlay Graft Failure: A Case Report.

Reconstruction of bone loss in the alveolar ridge has long been challenging. Autologous bone grafts are considered as the "golden standard," while little research has focused on how to repair pronounced alveolar bone defects after autologous bone graft failure. The aim of this study was to detail a method based on the titanium mesh technique coupled with particulate coral hydroxyapatite to solve the onlay graft failure. With bone deficiency in the No. 11 and No. 24-25 regions, we harvested 2 autologous bone blocks for reconstruction. Two weeks after transplantation, the graft in the No. 11 region had healed uneventfully, while the graft in the anterior mandible became infected because of soft tissue dehiscence. After removal of the failed autologous bone block, pure coral hydroxyapatite stabilized within titanium mesh was used for alveolar rehabilitation. Six months later, the width of the local alveolar bone was evaluated. After the titanium mesh was removed, a biopsy was performed to study bone regeneration by micro computerized tomography and histology, following by a standard Straumann implant insertion. Although there was wound dehiscence 14 days after bone augmentation, repeated local rinsing and anti-inflammation therapy controlled the inflammatory reaction. The total horizontal bone gain was 4.2 ± 0.5 mm. Micro computerized tomography revealed that the closer the coral hydroxyapatite was to the host bone, the more was resorbed and the more bone regenerated. Histology showed mature lamellar bone structures, with evident residual coral hydroxyapatite. A 3-year follow-up revealed stable bone around the dental implant and successful function of the implant-born prosthesis. This study proposes that the method of particulate coral hydroxyapatite sheltered by titanium mesh is a promising solution in handling alveolar bone augmentation failure. More cases are needed for further research to form an efficient treatment procedure.

Pre-augmentation soft tissue expansion improves scaffold-based vertical bone regeneration - a randomized study in dogs.

OBJECTIVE: Soft tissue (ST) dehiscence with graft exposure is a frequent complication of vertical augmentation. Flap dehiscence is caused by failure to achieve tension-free primary wound closure and by the impairment of flap microcirculation due to surgical trauma. Soft tissue expansion (STE) increases ST quality and quantity prior to reconstructive surgery. We hypothesized that flap preconditioning using STE would reduce the incidence of ST complications after bone augmentation and that optimized ST healing would improve the outcome of bone regeneration. MATERIALS AND METHODS: Self-filling tissue expanders were implanted in mandibular bone defects in ten beagle dogs. After expansion, alloplastic scaffolds were placed for vertical bone augmentation in STE sites and in control sites without STE pre-treatment. ST flap microcirculation was analysed using laser Doppler flowmetry. The incidence of graft exposures was evaluated after 2 weeks. Bone formation was assessed after 2 months, using histomorphometry and immunohistochemistry. RESULTS: Test sites showed significantly less impairment of perfusion and faster recovery of microcirculation after bone augmentation. Furthermore, no flap dehiscences occurred in STE sites. Bone regeneration was found in both groups; however, significantly greater formation of new bone was detected in test sites with preceding STE. CONCLUSIONS: Preconditioning using STE improved ST healing and bone formation after vertical augmentation. The combination of STE and the subsequent placement of alloplastic scaffolds may facilitate the reconstruction of severe bone defects.

Oral health-related quality of life and implant therapy: A prospective multicenter study of preoperative, intermediate, and posttreatment assessment.

PURPOSE: Loss of teeth is associated with a significant reduction in quality of life. The aim of this prospective multicenter study was to assess the impact of dental implants on oral health-related quality of life (OHRQoL). MATERIAL AND METHODS: Patients with various kinds of indications for dental implants ranging from single-tooth loss to edentulous jaws were included. Quality of life related to dental implants was assessed through the Oral Health Impact Profile (OHIP-G 21), which has a score from 0 to 20 in healthy patients. RESULTS: In total, 8689 patients from 17 centers from 2009 to 2014 were enrolled in the study. The sex distribution was almost even (53.3% men, 46.7% women). The most frequent indications for the insertion of dental implants were free-end gaps (30.6%) and posterior single-tooth gaps (27%). In all, 12.4% of patients had an edentulous jaw. For all indications, patients reported significant changes in mean OHIP scores after prosthetic reconstruction. The most significant improvements in the OHIP score occurred in the groups of patients with edentulous jaws (pretreatment score: 42.3) after prosthodontic reconstruction (score: 24.8) and in the patient group with an anterior single-tooth gap (pretreatment score: 36.4) after prosthodontic reconstruction (score: 24.8). CONCLUSION: The insertion of dental implants and prosthodontic rehabilitation led to an improved OHRQoL for patients with all indications for dental implants, with the most significant improvements in patients with edentulous jaws and anterior single-tooth gaps.

The current state of facial prosthetics ­ A multicenter analysis.

Even though modern surgical techniques are dominating reconstructive facial procedures, the capability to use facial epitheses for reconstruction is still an important skill for the maxillofacial surgeon. We present an international multicenter analysis to clarify which techniques are used to fixate facial prostheses. We contacted all maxillofacial departments in Germany, Austria, Switzerland and Norway which were registered with the German society for oral and maxillofacial surgery (DGMKG). These centers were asked via electronical mail to provide information on the type of epithesis fixation systems currently in use. The return rate from 58 departments was 43.1% (n = 25). Overall, implant fixation was the preferred fixation system (92%). Plates were the second most common fixation technique (32%). No centers reported the standard use of non-invasive fixation techniques for permanent epithesis fixation. The main retention systems in use were magnets (24/25), other retention systems are used much less often. The current preferred fixation technique for facial epitheses consists of implant-based, magnet-fixated epitheses. For nasal prostheses, a plate-based, magnet-fixated system is often used.

Occlusal rehabilitation in patients with congenitally missing teeth-dental implants, conventional prosthetics, tooth autotransplants, and preservation of deciduous teeth-a systematic review.

BACKGROUND: Implant patients with congenitally missing teeth share some common charateristics and deserve special attention. METHODS: The PICO question was "In patients with congenitally missing teeth, does an early occlusal rehabilitation with dental implants in comparison to tooth autotransplants, conventional prosthetics on teeth or preservation of deciduous teeth have better general outcomes in terms of survival, success and better patient centered outcomes in terms of quality of life, self-esteem, satisfaction, chewing function?" After electronic database search, a total of 63 relevant studies were eligible, of which 42 qualified for numerical data synthesis, 26 being retrospective studies. A data synthesis was performed by weighted means for survival/success/annual failure rates. RESULTS: The mean survival of implants was 95.3 % (prosthesis survival 97.8 %), autotransplants 94.4 %, deciduous teeth 89.6 %, and conventional prostheses 60.2 %. The implant survival in children, adolescents, and adults was 72.4, 93.0, and 97.4 %. Annual failure rates of implants 3.317 %, autotransplants 1.061 %, deciduous teeth 0.908 %, and conventional prostheses 5.144 % indicated better results for natural teeth and more maintenance needs for the both prosthetic treatments. The mean OHIP score was 27.8 at baseline and a mean improvement of 14.9 score points was reported after implant prosthetics. The mean satisfaction rates were 93.4 (implants), 76.6 (conventional prostheses), 72.0 (autotransplants), and 65.5 % (orthodontic space closure). CONCLUSIONS: In synopsis of general and patient-centered outcomes, implants yielded the best results, however, not in children <13 years. Autotransplants and deciduous teeth had low annual failure rates and are appropriate treatments in children and adolescents at low costs. Conventional prosthetics had lower survival/success rates than the other options. Due to heterogeneity and low number of studies, patient-reported outcomes in this review have to be interpreted with caution.

Improvement of microcirculation and wound healing in vertical ridge augmentation after pre-treatment with self-inflating soft tissue expanders - a randomized study in dogs.

OBJECTIVES: We investigated the effect of soft tissue expansion (STE) on vertical ridge augmentation with regard to the incidence of wound dehiscences and the impairment of microcirculation in dogs, and the applicability of laser Doppler flowmetry (LDF) to explore the relation between microcirculation and wound healing. MATERIAL AND METHODS: Bone defects were created on both mandibular sides in ten beagle dogs by extraction of premolars and removal of bone. Six weeks later, self-filling tissue expanders were implanted in randomly assigned test sites. After 5 weeks of expansion, vertical augmentation was carried out in test and control sites using calvarial onlay grafts side by side with granular biphasic calcium phosphate covered with a resorbable polyethylene glycol membrane. Microcirculation was evaluated with laser Doppler flowmetry (LDF). The incidence of wound dehiscences was evaluated after 2 weeks. The validity of LDF to predict dehiscences was evaluated by construction of receiver operating characteristic (ROC) curves. RESULTS: After augmentation, test sites showed significantly better perfusion than control sites without preceding STE (P = 0.012). Three days after surgery, perfusion was still significantly decreased in control sites (P = 0.005), while microcirculation in test sites had returned to pre-surgical levels. After 2 weeks, healing in test sites was good, whereas eight dehiscences were found in control sites (P = 0.002). ROC curves showed that microcirculation levels immediately after augmentation surgery significantly predicted subsequent wound dehiscences (AUC = 0.799, CI 0.642-0.955, P = 0.006). CONCLUSIONS: Laser Doppler flowmetry is suitable for evaluation of soft tissue microcirculation after ridge augmentation. STE reduced the impairment of microcirculation caused by vertical ridge augmentation and decreased the incidence of wound dehiscences in the investigated animal model.

Tissue engineering of a vascularized bone graft of critical size with an osteogenic and angiogenic factor-based in vivo bioreactor.

Engineering a large vascularized bone graft is a much greater challenge than engineering small bone tissues. Although this is essentially feasible through an osteogenic factor-based in vivo bioreactor technique, the ossification needs improving. This study was aimed to investigate the possibility and efficacy of ectopic cultivation of sizeable bone grafts with large angiogenic and osteogenic factor-loaded natural bovine bone mineral (NBBM) scaffolds. For this purpose, six groups of sizeable composite scaffolds were constructed, consisting of a titanium mesh cage of NBBM or a mixture of NBBM/autogenous bone particles (AB), which were preloaded with 660 µg recombinant human bone morphogenetic protein-7 (rhBMP-7) and/or 4 µg recombinant human vascular endothelial growth factor165 (rhVEGF165). The scaffolds were implanted in bilateral latissimus dorsi muscles in eight pigs to construct in vivo bioreactors. Sequential fluorescence labeling was then applied to trace bone formation at the early stage. The implants were retrieved 12 weeks later. The undecalcified sections were observed in turn under the fluorescence microscope and light microscope to investigate early stage osteogenesis and histology. Moreover, new bone density (BD) was measured with histomorphometry. Compared with rhBMP-7-delivered NBBM scaffolds, rhVEGF165/rhBMP-7-delivered NBBM scaffolds were with more intense intra-scaffold osteogenesis at the early stage and the ultimate sizeable bone grafts of microstructurally more lamellae and trabeculae, and quantitatively higher BD (31.93% vs. 22.37%, p<0.01). This study demonstrated that as for the endocultivation of a large bone graft with bioactive factor-based in vivo bioreactor technique, dual delivery of rhVEGF165/rhBMP-7 has synergic effects on improving early stage bone formation and subsequently bone quality and quantity of the bone grafts.

Submucosal implantation of soft tissue expanders does not affect microcirculation.

AIM: To investigate the effect of submucosal implantation of self-filling osmotic tissue expanders on mucosal microcirculation. MATERIAL AND METHODS: In ten beagle dogs, all premolars were extracted on both sides of the mandible. Tooth-supporting bone and excess soft tissue were removed to mimic a severely resorbed edentulous ridge. Six weeks later, tissue expanders with 0.7 ml final volume were implanted into a submucosal pouch at randomly selected test sites, while contralateral sites served as untreated controls. Microcirculation was assessed in perfusion units (PU) before surgery, after local anaesthesia, directly after surgery, and after 1 and 3 days, using Laser Doppler flowmetry. RESULTS: Local anaesthesia caused a significant decrease of blood flow from baseline (zero) to -6.4 PU (median; Q1 -10.5; Q3 -0.9; P = 0.006); however, no additional significant decrease was recorded after completion of surgery. Blood flow showed significant increases to -3.6 PU (median; Q1 -11.3, Q3 2.1; P = 0.02) and -4.0 PU (median; Q1 -9.2, Q3 1.1; P = 0.013) after 1 and 3 days, respectively, when compared to the measurements obtained after application of local anaesthesia and completion of surgery. Blood flow had returned to unimpaired baseline levels 1 day after surgery (P > 0.05). CONCLUSIONS: Submucosal implantation of self-filling osmotic tissue expanders results in only momentary disturbance of microcirculation. The minor impairment of perfusion may explain the consistently good outcomes of submucosal implantation of these tissue expanders.

Antimicrobial peptide coating of dental implants: biocompatibility assessment of recombinant human beta defensin-2 for human cells.

PURPOSE: Artificial materials such as dental implants are at risk of bacterial contamination in the oral cavity. Human beta defensins (HBDs), small cationic antimicrobial peptides that exert a broad-spectrum antibacterial function at epithelial surfaces and within some mesenchymal tissues, could probably help to reduce such contamination. HBDs also have protective immunomodulatory effects and have been reported to promote bone remodeling. The aim of this study, therefore, was to investigate the influence of recombinant HBD-2 on the proliferation and survival of cells in culture. MATERIALS AND METHODS: Human mesenchymal stem cells (hMSCs), human osteoblasts, human keratinocytes (control), and the HeLa cancer cell line (control) were incubated with recombinant HBD-2 (1, 5, 10, or 20 µg/mL). Cell proliferation and cytotoxicity were evaluated via a water-soluble tetrazolium salt (WST-1) and lactate dehydrogenase assays, respectively. RESULTS: HBD-2 was not toxic in any tested concentration to hMSCs, osteoblasts, keratinocytes, or HeLa cells. Furthermore, proliferation of hMSCs and osteoblasts increased after treatment with HBD-2 at all tested concentrations, and keratinocyte proliferation increased when treated at 20 µg/mL. In contrast, HeLa cancer cells were not affected by HBD-2 as tested. CONCLUSIONS: HBD-2 is not only biocompatible but also promotes proliferation of hMSCs, osteoblasts, and keratinocytes in culture. Further investigation of HBD-2 functional surface coating of artificial materials is recommended.

Bone-to-implant contact after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios in mini pigs.

OBJECTIVES: The objective was to test the hypotheses: (i) no differences in bone-to-implant contact formation, and (ii) no differences between the use of autogenous mandibular or iliac bone grafts, when autogenous bone, Bio-Oss mixed with autogenous bone, or Bio-Oss is used as graft for the maxillary sinus floor augmentation. MATERIAL AND METHODS: Bilateral sinus floor augmentation was performed in 40 mini pigs with: (A) 100% autogenous bone, (B) 75% autogenous bone and 25% Bio-Oss, (C) 50% autogenous bone and 50% Bio-Oss, (D) 25% autogenous bone and 75% Bio-Oss, or (E) 100% Bio-Oss. Autogenous bone was harvested from the iliac crest or the mandible and the graft composition was selected at random and placed concomitant with the implant placement. The animals were euthanized 12 weeks after surgery. Bone-to-implant contact was estimated by stereological methods and summarized as median percentage with 95% confidence interval (CI). Bone-to-implant contact formation was evaluated by fluorochrome labelling and assessed by median odds ratios (OR) with 95% (CI). RESULTS: Median bone-to-implant contact was: (A) 42.9% (95% CI: 32.1-54.5%), (B) 37.8% (95% CI: 27.1-49.9%), (C) 43.9% (95% CI: 32.6-55.9%), (D) 30.2% (95% CI: 21.6-40.3%), and (E) 13.9% (95% CI: 11.4-16.9%). Bone-to-implant contact was significantly higher for A, B, C, D as compared to E (P < 0.0001). Bone-to-implant contact was not significantly influenced by the ratio of Bio-Oss and autogenous bone (P = 0.19) or the origin of the autogenous bone (P = 0.72). Fluorochrome labelling revealed extensive variation in bone-to-implant contact formation over time. The labelling at weeks 2-3 was significantly increased with A compared to E (OR = 8.1 CI: 5.0-13.1, P < 0.0001), whereas E showed a significantly increased labelling at weeks 8-9 compared to A (OR = 0.5 CI: 0.3-0.7, P = 0.0028). CONCLUSIONS: The hypothesis of no differences in bone-to-implant contact between the various treatment modalities was rejected since the bone-to-implant contact was significantly increased with autogenous bone or Bio-Oss mixed with autogenous bone as compared to Bio-Oss. Early bone-to-implant contact formation was more advanced with autogenous bone. No differences between the use of mandibular or iliac bone grafts were observed since the bone-to-implant contact was not significantly influenced by the origin of the bone graft.

Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft: a systematic review.

AIMS: The objective of the present systematic review was to test the hypothesis of no differences in the implant treatment outcome when Bio-Oss or Bio-Oss mixed with autogenous bone is used as graft for the maxillary sinus floor augmentation (MSFA) applying the lateral window technique. MATERIAL AND METHODS: A MEDLINE (PubMed) search in combination with a hand search of relevant journals was conducted by including human studies published in English from January 1, 1990 to June 1, 2010. The search provided 879 titles and 35 studies fulfilled the inclusion criteria. Considerable variation in the included studies prevented meta-analysis from being performed and no long-term study comparing MSFA with the two treatment modalities was identified. Also, the survival of suprastructures after the two augmentation procedures was not compared within the same study. RESULTS: The 1-year implant survival was compared in one study demonstrating no statistically significant difference. The implant survival was 96% with Bio-Oss and 94% with a mixture of 80% Bio-Oss and 20% autogenous mandibular bone. Addition of a limited amount of autogenous bone to Bio-Oss seemed not to increase the amount of new bone formation and bone-to-implant contact compared with Bio-Oss. CONCLUSIONS: Therefore, the hypothesis of no differences between the use of Bio-Oss or Bio-Oss mixed with autogenous bone as graft for MSFA could neither be confirmed nor rejected.

Survival of transplanted rat bone marrow-derived osteogenic stem cells in vivo.

This study was designed to trace bone marrow-derived stromal cells (MSC) after implantation in an ectopic rat model of bone tissue engineering. MSC were isolated from adult donor rats, expanded, seeded on a hydroxyapatite/ß-tricalcium phosphate bone graft substitute (Straumann® BoneCeramic), and cultivated until confluent. Before subcutaneous implantation of seeded constructs and controls (unseeded bone graft substitute) in isogenic rats (n = 32), cells were labeled with the fluorescent dye carboxyfluoresceine-diacetate-succinimidyl-ester. Specimens were harvested at sacrifice on day 1, 3, 7, or 14 after implantation (n = 8 per group) and processed for histology (hematoxylin and eosin, CD68, 4',6-diamidino-2-phenylindol). Carboxyfluoresceine-diacetate-succinimidyl-ester-labeled transplanted cells were quantified in decalcified sections (50 fields of view per specimen) at 488 nm. Over time, transplanted cells decreased in number from 31.3 ± 2.3 (day 1) to 9.2 ± 1.1 (day 3) and 0.3 ± 0.1 (day 7) (p < 0.001). Fourteen days postimplantation MSC could no longer be identified. Additionally, starting on day 3 postimplantation, cellular disintegration was noted. Multinucleated giant cells were present in constructs and controls on day 7 and increased to day 14 postimplantation. These results indicate that ectopically transplanted MSC survive for a rather short time after implantation. Possible reasons for early cell death are discussed.