Karl Andreas Schlegel

Universitätsklinikum Erlangen · Department of Oral and Cranio-Maxillofacial Surgery

Aim: This randomized controlled clinical study focused on graft volume alterations after sinus floor augmentation with a deproteinized bovine bone mineral (DBBM, Geistlich Bio-Oss®), deproteinized porcine bone mineral (DPBM, THE GRAFT®) or a biphasic calcium phosphate (BCP, OSOPIA®). Material and methods: 28 patients with edentulous situations in...

In addition to full-guided planning before surgery, digital processes can also be used directly after implant placement. In this approach, the implant position is recorded directly after the insertion of the implant body via scan bodies. Afterward, the digital data can be sent to the referring colleagues for immediate restoration, for example, to o...

Loading protocols can be combined with simultaneous extraction and immediate implant placement. Some examples are immediate loading (with occlusion) or immediate restoration (without occlusion) using a temporary denture. However, in cases with poor primary implant stability, substantial bone augmentation, implants of reduced dimensions, parafunctio...

Preoperative planning for guided surgery includes software that shows a three-dimensional representation of the clinical and the radiographic matched data. The exact implant position and template design will be coded in the surgical guide. The template can be produced in specialized dental laboratories or one of the milling centers of the program m...

Full-guided surgery includes different steps that might lead to complications. The measurement inaccuracy within CBCT scans was evaluated to be up to 0.26 mm. The resolution of the extraoral scanner used to scan the cast models is specified by the manufacturer as less than 20 μm. Deviations in intraoral scans depend on the extension of the optical...

In the next chapters, we would like to discuss various initial situations and treatment options on the subject of guided surgery. For this purpose, we will present a number of clinical cases.

An initial treatment plan is key. There are three main existing workflows. In principle, a cast model or intraoral scans with a wax-up/mock-up and CBCT or CT scans of the patient are necessary. Subsequently, before planning implant positioning, these files containing the clinical and radiological information are matched together. Optical impression...

Every guided surgery kit is specific to the individual implant system. The surgical protocol, which includes implant size and drilling sequence, is followed. On the one hand, the pilot drilling or the complete implant bed preparation can be performed as part of half-guided surgery. With full-guided surgery, on the other hand, the implant is also in...

Full-guided surgery may be of enormous help, especially in full-arch edentulous cases. Due to the esthetic and hygienic challenges in full-arch crown and bridge prostheses, the use of a removable denture, such as an overdenture supported by a bar, telescope, or individual attachments, may be recommended in individual cases. A temporary tooth setup...

The pros of guided surgery are precise surgery planning, minimal invasiveness, exact implant positioning, shorter surgical time, and possibilities of a flapless approach. The cons of guided surgery include higher costs for the surgeon and patient, longer preoperative planning time, and difficult radiological estimation of bone quality and quantity...

From the very beginning, the most important advantages of guided surgery are a comprehensive diagnosis and treatment planning and the 3D examination of the anatomical condition in every case. Anatomical structures and bone quality may vary not only between female and male patients but also between both jaws and within adjacent implant sites. For th...

Objectives The aim of this study was to investigate if bone regeneration can be promoted by homologous transplantation of STRO-1 sorted (STRO-1+) porcine tooth germ mesenchymal stem cells (TGSCs) with the combination of polyethylenglycol (PEG)-based hydrogel and biphasic calcium phosphate (BCP) scaffolds. Material and methods TGSCs were isolated f...

This book is an accurate introduction to guided implantology. As practitioners with many years of experience, the authors present an important basis for scientific findings and a valid decision-making aid for digital oral surgery. Readers are invited to learn step by step about full guided surgery. Numerous full color images demonstrate the anatomi...

Polyurethanes have the potential to impart cell-relevant properties like excellent biocompatibility, high and interconnecting porosity and controlled degradability into biomaterials in a relatively simple way. In this context, a biodegradable composite material made of an isocyanate-terminated co-oligoester prepolymer and precipitated calcium carbo...

Abstract Aim: This study evaluates the early volumetric changes after buccal soft tissue contour augmentation around implants with a porcine collagen matrix (CM) vs. the subepithelial connective tissue graft (SCTG) from the palate. Materials and methods: 14 patients were enrolled after early implant placement with simultaneous contour augmentatio...

In the article by Möst et al., entitled "Osseous ingrowth in allogeneic bone blocks applied for vertical bone augmentation: a preclinical randomized controlled study.

Objectives The aim of the present study was the qualitative and quantitative evaluation of osseous graft consolidation using allogeneic bone blocks for vertical bone augmentation in an animal model. Material and methods Standardised allogeneic and autologous bone blocks were fixed on the frontal skull of 20 adult female pigs and covered with a res...

Objectives The preclinical study aimed to establish a standardized preclinical model to investigate osseous graft consolidation in defect configurations of limited regenerative capacity. Material and methods Critical size defects (CSD) were prepared and titanium tubes inserted for defect separation from local bone in the forehead area of 18 pigs....

Aim: To compare ten-month histological and immunohistological outcomes after soft tissue thickening around teeth with a porcine collagen matrix (CM) versus a subepithelial connective tissue graft (SCTG). Material and methods: In eight beagle dogs, soft tissue thickening of the buccal gingiva of upper canines was performed with the SCTG or the CM...

Objectives: To evaluate whether zirconia implants demonstrate differences in hard and soft tissue integration compared to titanium implants in preclinical studies. Material and methods: In March 2017, electronic (MEDLINE, EMBASE) and hand search was performed to identify preclinical studies comparing zirconia and titanium implants. Primary outco...

The aim of this study was to assess the clinical and microbiological parameters around dental zirconia and titanium implants compared with natural teeth during experimental plaque accumulation. Clinical parameters were evaluated (gingival index, plaque index, bleeding on probing, and probing pocket depth). Microbiological samples were analyzed for...

The purpose of this study was to assess host-derived parameters around dental zirconia and titanium implants and natural teeth during the occurrence of mucositis. After 4 weeks of perfect oral hygiene, 16 clinically profiled patients were asked to refrain from oral hygiene for 2 weeks, resulting in experimental plaque accumulation. This was followe...

Objectives To evaluate implant survival, peri‐implant marginal bone loss, technical, and biological complications as well as aesthetic outcomes of zirconia implants in clinical studies. Material and Methods Electronic (Medline, Embase) and hand searches were performed to identify clinical studies published between January 2004 and March 2017 inves...

Objectives Working Group 2 was convened to address topics relevant to prosthodontics and dental implants. Systematic reviews were developed according to focused questions addressing (a) the number of implants required to support fixed full‐arch restorations, (b) the influence of intentionally tilted implants compared to axial positioned implants wh...

Purpose: Soft tissue interactions with ceramic dental implants have previously been shown to have favorable esthetic outcomes. This study aimed to evaluate the papilla-crown proportion around zirconia implants in a 3-year follow-up study and the correlation between the gingival biotype and changes in papillary height. Materials and methods: This...

The posterior segment of the edentulous region represents an anatomical peculiarity when planning for the restoration of missing teeth with dental implants. Alveolar atrophy and pneumatization of the maxillary sinus often preclude the insertion of implants at standard lengths ( > 8 mm). In cases of advanced atrophy and a residual bone height of les...

The study aimed to evaluate the papilla-crown proportion around zirconia implants in a 3-year follow- up study. In addition, the correlation between the gingival biotype and changes in papillary height were evaluated. This was a prospective study of 39 patients with 40 single-gap implants assessing the papilla-crown proportion after 3 months, 1 yea...

The aim of this study was to measure bone levels around zirconia implants during follow-up of up to 3 years. Additionally, the effect of clinical contact point positions on the papilla deficit was evaluated. Eighty-one patients with 105 zirconia implants were examined at the 3-year follow-up. Bone levels were measured on the date of implant placeme...

Objectives This study aimed to assess the impact of different abutment materials on peri-implant tissue regeneration after surgical treatment of peri-implantitis in a large animal model. Material and Methods Titanium implants (n = 51) were inserted in the upper and lower jaw of eight beagle dogs and a peri-implant infection was induced. After two...

Stem cells of dental origin emerged as a new source for the regeneration of tissues with advantages mainly including non-invasive collection procedures and lack of ethical contraversies with their harvest or use. In this study, porcine TGSCs (pTGSCs) were isolated from mandibular third molar tooth germs of 6-month-old domestic pigs. This is the fir...

Purpose The aim of the study was to evaluate the possibility of supracortical peri-implant bone formation after periosteal elevation. Materials and Methods Periosteal elevation with an elevation height of 5 or 10 mm was performed in an animal experiment with 24 female domestic pigs. For this purpose, four implants were inserted in the frontal bone...

The increasing number of digitization in dental medicine has also been recorded in implantology. In addition to the possibility of the three-dimensional representation of the jaw bone and the adjoining anatomical structures, virtual implant planning is also increasingly used. The implant planning programs required for this are often different in th...

In recent years, the number of patients undergoing bisphosphonate therapy and requesting a dental implant reconstruction has steadily increased. Ten years ago, implant treatments in such patient collectives were usually avoided due to a lack of evidence concerning implant survival. At the time, there was uncertainty regarding the relative risk of t...

The osseointegration of dental implants is the result of a complex array of biological processes, which mainly occur during the first few days following insertion. This article will review the transition from a primary- to a secondary stability and elucidate relevant influencing factors.

The aim of the study was to evaluate implant survival of reduced-diameter implants compared to regular-diameter implants. A retrospective evaluation of 154 Straumann Bone Level Roxolid(®) implants (diameter 3.3 mm) with SLActive(®)-surface in 107 patients, which were inserted between 2009 and 2010 in private practice, was performed. The mean observ...

The cover image, by Christian M Schmitt et al., is based on the Animal Experiment Soft tissue volume alterations after connective tissue grafting at teeth: the subepithelial autologous connective tissue graft versus a porcine collagen matrix – a pre-clinical volumetric analysis, DOI: 10.1111/jcpe.12547.

The pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) remains unknown, and the development of a reliable experimental model would help to improve our understanding of it. We used 12 domestic pigs of which 6 made up the experimental group and were treated with zoledronate 4 mg intravenously weekly for 5 weeks, while the control...

Objectives: The study aims to establish a peri-implant dehiscence-type bone defect in a diabetic animal model of human bone repair and to quantify the influence of diabetes on peri-implant bone regeneration. Material and methods: Experimental diabetes was induced in three domestic pigs by streptozotocin. Three animals served as healthy controls....

Long-term dental implant success depends on bone quality and quantity. Insufficient bone quantity makes pre- or intraoperative augmentative procedures necessary. For this purpose, autologous, allogeneic, xenogeneic, and alloplastic bone substitute materials (BSMs) are available, which differ in their capacity for osteogenesis, osteoconduction, and...

Peri-implant soft tissues and their management have become increasingly important in the last few years. In terms of the significance of peri-implant soft tissues on the health and inflammatory state of implants, a slight trend has emerged in the literature that recommends sufficient dimensions (> 2 mm width) of keratinized peri-implant soft tissue...

Aim: This study evaluates a porcine collagen matrix (CM) for soft tissue thickening in comparison to the subepithelial connective tissue graft (SCTG). Material and methods: In eight beagle dogs, soft tissue thickening was performed at the buccal aspects of the upper canines (SCTG and CM). Impressions were taken before augmentation (i1), after su...

Augmentation of the alveolar crest is often a necessary condition for dental implants in patients with congenital or acquired bone loss. Furthermore, the augmentation can improve the function, esthetic and prognosis of implants and helps to prevent surgical complications. The introduction of short and diameter-reduced implants led to discussion abo...

Objectives: The overall aim of the study was to investigate a biofunctionalized implant surface with electrochemically deposition of hydroxyapatite and the synthetic peptide (P-15) and its effect on osseointegration. Material and methods: Three modified implant types of ANKYLOS(®) C/X implants were used; (1) machined implants used as negative co...

Objectives The animal study aims to evaluate a new experimental model for measuring sole the influence of the surface characteristics independent from implant macro-design on the level of osseointegration by registering the pull-out strength needed for removal of experimental devices with different surfaces from artificial defects. Material and me...

The desire for implant-supported prostheses is steadily increasing in edentulous patients. For the clinician, the restoration of edentulous jaw is a challenge in implant prosthodontics because of alveolar atrophy and changes in the maxillomandibular relationship. Three-dimensional imaging shows the extent of the residual bone volume. In this case r...

The aim of this study is to evaluate the effects of nanoporous anodic aluminum oxide (alumina) with pore diameters from 15 to 40 nm on osteoblasts (hFOB) and fibroblasts (HFF). After 7 days, a significantly higher proliferation of osteoblasts with a regular cell morphology is visible on the 40 nm samples compared to the 15 nm pore diameter (p = 0.0...

The present study aimed to evaluate the influence of implant length on implant survival and patient satisfaction during the first 24 months in function. A retrospective cohort of 312 "short" Straumann(®) SLActive(®) implants (length ≤ 8 mm) in 224 patients, which were inserted between 2008 and 2010 in private practice, were evaluated. The mean obse...

Today, the use of dental implants represents a reliable treatment option for functional and esthetic rehabilitation of edentulous or partially edentulous jaws. However, patient-related risk factors may contraindicate surgical treatment and can consequently have an impact on implant survival and success rates. Patients with metabolic diseases (eg, d...

Today, the use of dental implants represents a reliable treatment option for functional and esthetic rehabilitation of edentulous or partially edentulous jaws. However, patient-related risk factors may contraindicate surgical treatment and can consequently have an impact on implant survival and success rates. Patients with metabolic diseases (eg, d...

Porcine collagen matrices are proclaimed being a sufficient alternative to autologous free gingival grafts (FGG) in terms of augmenting the keratinized mucosa. The collagen matrix Mucograft(®) (CM) already showed a comparable clinical performance in the early healing phase, similar histological appearance, and even a more natural appearance of augm...

This study aimed to compare autologous bone (AB), bovine bone (BB), and equine bone (EB) blocks with regard to de novo bone formation, connective tissue, and residual bone substitute material portions in a standardized defect animal model. In the frontal skull of 20 pigs, 106 standardized cylindrical "critical size defects" were prepared. Defects w...

Aim: Microvascular free tissue transfer is a standard method in head and neck reconstructive surgery. However, previous radiotherapy of the operative region is associated with an increased incidence in postoperative flap-related complications and complete flap loss. As transforming growth factor beta (TGF-β) 1 and galectin-3 are well known markers...

We present a mild one-pot freeze gelation process for fabricating near-net, complex-shaped hydroxyapatite scaffolds and to directly incorporate active proteins during scaffold processing. In particular, the direct protein incorporation enables a simultaneous adjustment and control of scaffold microstructure, porosity, resorbability and enhancement...

AimThis study aimed to evaluate the healing of peri-implant defects grafted with microparticles (MPs).Material and Methods Six domestic pigs received nine standardized defects at the calvaria, and an implant was inserted in the middle of each defect. The space between the implant and lateral bone portion was filled with MP pellets (n = 18) or MP su...

Objectives This investigation focused on histological characteristics and 5-year implant survival after sinus floor augmentation with anorganic bovine bone (ABB, Bio-Oss®) and ABB plus autologous bone (AB) with a ratio of 1/1.Material and methodsNineteen consecutive patients with bony atrophy of the posterior edentulous maxilla and a vertical bone...

Both Osteoradionecrosis (ORN) and Bisphosphonate associated osteonecrosis of the jaws (BRONJ) present clinically as regions of exposed necrotic bone. The study aimed to demonstrate the histopathological differences behind the observed clinical similarities. Ten ORN specimens and ten BRONJ specimens were used, as well as ten samples of normal mandib...

Objectives The long-term outcome after sinus augmentation with autogenous bone or a bovine xenograft (Bio-Oss®) was assessed in 47 patients. Inclusion criterion was a vertical dimension of the maxilla of <4 mm. After a functional loading period of 60 months, implant survival and reduction in the augmentation height were compared between the two gro...

The study assessed the use of a new xenograft material. The aim of the present in vivo experiment was to obtain information on the clinical results and the rate of bone formation using two new experimental bone substitutes compared with an established bovine bone substitute and the autogenous graft, which is considered the gold standard for graftin...

Nano-scale surface modification of biomedical implant materials offers enhanced biological activity concerning protein adsorption and cell adherence. Nano-porous anodic alumina (AAO) layers were prepared by electrochemical oxidation of thin Al-seed layers in 0.22 M C2H2O4 applying anodization voltages of 20 - 60 V. The AAO layers are characterized...

The scapular/parascapular free flap was described by Saijo in 1978 and has since then been widely used in reconstructive procedures. This is a retrospective study, describing our experience with the use of free scapula/parascapular flap in 130 reconstructions over a period of 5 years in the Department of Oral and Maxillofacial Surgery of the Univer...

Rhabdomyomas are rare benign mesenchymal tumors with skeletal muscle differentiation and a predilection for the head and neck area. A 38-year-old man presented with persistent, slowly growing, painless swelling in the left inner cheek for 2½ years. The lesion was detected during routine dental examination and was considered to represent a mucocele....

Mesenchymal stem cells such as bone marrow stromal cells and Adipose-derived stem cells are widely being used for clinical applications in regenerative medicine. Dental stem cell sources such as dental pulp stem cells, stem cells from human exfoliated deciduous teeth, periodontal ligament stem cells, stem cells from apical papilla, dental follicle...

The objective of this study was to investigate if osseous regeneration can be accelerated by involvement of periosteal tissue. Bone defect regeneration could be accelerated by the involvement of periosteal tissue if osteogenic cell signalling is maintained within the defect. It was questioned if local cell-mediated BMP-2 gene delivery makes a cell...

A free gingival graft (FGG) is currently the gold standard for augmenting small areas of keratinized mucosa. As of yet, no satisfactory results were found with synthetic transplants or autologous transplants derived from tissues other than palatal mucosa. Nonetheless, disadvantages include the inability to harvest larger grafts, high morbidity rate...

An autologous free gingival transplant is currently the gold standard for augmenting small areas of keratinized mucosa. This case report describes an alternative augmentation procedure of keratinized pen-implant mucosa with the use of Mucograft and an implant-supported vestibular retention splint. A vestibuloplasty was performed prior to the insert...

In 2008, a consensus meeting of the Association for Dental Education in Europe stated that dental implant treatment represents a popular treatment alternative and, therefore, it should be an integral part of dental student pre-graduate education. In 2009, the Friedrich-Alexander University, Erlangen-Nuremberg implemented a voluntary, structured, ed...

Inflammatory pen-implant diseases are one of the main reasons for the loss of endosseous implants. Bacterial infection initially leads to an inflammation of the soft tissue and later to a progressive loss of the alveolar bone. In some cases, this destruction of hard tissue leads to a complete loss of osseointegration of the implant. In this case, a...

Purpose The aim of study paper is to present an overview of osseointegration of dental implants, focusing on tissue response, surface modifications and future perspective. Discussion Great progress has been made over the decades in the understanding of osseous peri-implant healing of dental implants, leading to the development of new implant mat...

Purpose In order to determine whether a newly developed implant material conforms to the requirements of biocompatibility, it must undergo rigorous testing. To correctly interpret the results of studies on implant material osseointegration, it is necessary to have a sound understanding of all the testing methods. The aim of this overview is to elu...

This animal study evaluated bone healing around titanium implant surfaces biomimetically coated with bone morphogenic protein-2 (BMP-2) and/or vascular endothelial growth factor (VEGF) by examining bone matrix proteins and mineralisation. Five different implant surfaces were established: acid-etched surface (AE), biomimetic calcium phosphate surfac...

Promising biomaterial characteristics of diamond-coatings in biomedicine have been described in the literature. However, there is a lack of knowledge about implant osseointegration of this surface modification compared to the currently used sandblasted acid-etched Ti-Al6-V4 implants. The aim of this study was to investigate the osseointegration of...

Stafne cysts are often defined as static lesions located in the angle of the mandible. Consequently many authors have proposed that there is no need for surgical treatment of these bony defects on the lingual side of the mandible. This article describes the case of a 55-year-old patient, in whom a Stafne cyst showed a significant enlargement, reach...

Sufficient intraoral and extraoral wound healing is a prerequisite for symptom-free, esthetic, and functional rehabilitation in oral and maxillofacial surgery. Because of the constantly increasing survival rates of the Western population, aging represents a factor that should be included in the planning of surgical interventions. Aging skin, oral m...

Objectives The augmentation of the alveolar ridge using iliac cortico-spongeous bone grafts is routinely used. However, bone grafts show a substantial degree of resorption, which may negatively affect the long-term success of dental implants in the augmented area. The aim of this study was to evaluate the effect of a deproteinized bovine bone matri...

Objectives This investigation focused on long-term changes in graft height, implant survival rate, and peri-implant tissue conditions of dental implants placed in alveolar ridges after augmentation procedures with a follow-up of 10years. Material and methodsWe conducted a retrospective cohort study with prospective long-term follow-up of 25 patient...

Background: A free gingival graft (FGG) is currently the gold standard for augmenting small areas of keratinized mucosa. The porcine collagen matrix (CM) represents an alternative to autologous tissue harvesting. This study aims to compare the CM versus FGGs for augmenting keratinized peri-implant mucosa based on clinical and histologic evaluation...

Sufficient bone in both the vertical and horizontal dimensions is a prerequisite for successful implant therapy. Over the course of the recent development of modern dentistry, different ways and techniques to create adequate bone levels have been developed. In particular, focus is placed on bone replacement materials that promise to eliminate donor...

To compare the effect of ceramic and metal implant materials on the expression pattern of inflammatory cytokines in peri-implant soft tissue. This split-mouth study included patients who received dental implants. In each patient, four different materials were used for the implant cover screws: the ceramic material titanium niobium oxynitride ([Ti,N...

Objective: This study aimed at identifying the ideal concentration of a biofunctional surface coating of dental implants with a synthetic peptide (P-15). In a previous study, P-15 was shown to enhance osseointegration parameters. Material and methods: Implants (modified ANKYLOS(®) A8; FRIADENT Plus(®) surface) with five different concentrations...

In the present paper we report the oral findings of a patient who was diagnosed with hyperoxaluria. Hyperoxalurias can basically be classified as primary and secondary, with the first being inborn errors of metabolism and the second a result of excessive oxalate intake. Primary hyperoxalurias form a rare group of metabolic diseases that are inherit...

Objective: This investigation focused on a comparison of clinical and histological characteristics after sinus floor augmentation with biphasic calcium phosphate (BCP, Straumann BoneCeramic(®) ), anorganic bovine bone (ABB, Geistlich Bio-Oss(®) ), mineralized cancellous bone allograft (MCBA, Zimmer Puros(®) ), or autologous bone (AB). Materials a...