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Ectodermal dysplasias (EDs) form a large clinically and genetically heterogeneous group of manifestations characterized by dystrophy or agenesis of embryologic ectodermal derivatives. Therefore skin, nails, hair, teeth and secretory organs are mainly affected. Hypohidrotic ectodermal dysplasia (HED) is the most common ED syndrom. It is characterized by atrichosis or hypotrichosis, anodontia or hypodontia and hypohidrosis. Missing teeth or retarded eruption of teeth often leads to the diagnosis of ED, which emphasizes the significance of an appropriate dental examination. Tooth agenesis and its effects on craniofacial structures are often the most signicificant clinical and therapeutical problem. It is a challenge to manage the functional, esthetic and psychosocial needs of these patients and therefore requires the involvement of different specialists, such as pediatrists, pedodontists, oral surgeons and prosthodontists.

The combination of scanning technology and CAD/CAM procedures allows to significantly reduce working time clinically as well as for the dental laboratory. In comparison to conventional complete denture fabrication, the AvaDent® system provides specific trays and registration plates to complete all the required patient recordings and steps in the first appointment. By virtual modeling (CAD) and milling of the denture (CAM) out of a solid acrylic puck, time-consuming flasking and packing procedures are needless. Due to the abscence of any polymerisation shrinkage of the dentures, the precision of fit remains accurate. This system allows to efficiently deliver high-quality and cost-effective complete dentures for the edentulous patient in only two appointments. The clinical procedure is presented step-by-step and critically evaluated from the clinician’s point of view.

Applications such as “prepCheck” allow objective and consistent judgments of tooth preparations. Hereby the respective preparation is matched with a standardized preparation. Whereas the learning curve in the beginning is time-consuming, after some time the faculty members will be relieved from additional mentoring time in the preclinical simulation laboratory. Students independently get an objective self-assessment by the software. Time and effort at the moment are in a misbalance since three scans (preparation, occlusion record, opposite jaw) are necessary. A simple one-scan procedure would be preferable. “prepCheck” is considered as a user-friendly software. It will play an essential role in the objective assessment of students tooth preparations in the future education.

In dentist's daily practice, intraoral scanning systems are increased. Besides scanning of prepared teeth, also implants could be scanned intraorally. This clinical report describes the step-by-step techniques to scan digitally intraoral implants with two intraoral scanners (Lava™ C.O.S., 3M Espe and the CEREC AC connected with inLab MC XL, Sirona) for generating implant suprastructures without the use of impression materials, dental stone or implant impression copings. Different workflows, possibilities and limits by scanning dental implants are demonstrated.

Zirconia as a framework material is well established in fixed prosthodontics. However, for its application for removable dentures little experience exists. Zirkonzahn® has developed a copy-milling unit, that is a manually operated machine for the manufacture not only of frameworks but also of complete removable dentures. The aim of this case report is to show the step-by-step clinical and technical fabrication of a zirconia bar on implants and of a corresponding zirconia complete denture. The advantages and disadvantages of the system are presented and problems are critically discussed.

Regardless of the success of preventive measures the replace¬ment of missing teeth in young patients with caries-free dentitions is a daily challenge for the clinician. The decision-making process concerning the different treatment options is difficult, based on several equivalent solutions. Thereby the significance of minimal invasive approaches is steadily increasing. In indicated cases, resin-bonded fixed partial dentures which were introduced in the last century still represent a well documented and minimally invasive procedure, even in the era of dental implants. In this article, clinical aspects of a conventional, metal-based resin-bonded fixed partial dentures are discussed according to the current literature and the clinical steps are presented in a clinical case.

Surgical navigation allows precise implant placement and minimizes the risk of interferences with anatomical structures. Computerized implant planning based on tomographic data can be clinically realized by surgical templates. These are normally produced by stereo lithographic rapid prototyping. Accurate placement of virtually planned dental implants depends on a precise fabrication and positioning of the surgical template. Bone-, tooth-, implant-, and/or soft tissue-supported surgical templates allow for different micromovements. This report documents the diagnostics and surgical procedures of implant placement in an edentulous patient. Implant fixed complete dentures in the maxilla and mandible were planned. In the maxilla implants were inserted with the aid of a conventional surgical template. In the mandible a bone supported CT-guided surgical template was used.

For a simple and provisional retention of a removable prosthesis, less expensive direct retainers are an option compared to indirect cast gold copings with attachment. The Dalbo-Rotex-retainer and the Ticap-system are clinically established. The Locator Root attachment and the Würzburger Stift were recently introduced. The Locator Root attachment uses a massive profiled cylindrical post as a radicular anchorage. The Würzburger Stift has a small endodontic part which is retained by four spreadable lamellae in a convergent cavity. They further differ in the design of the male and female part. Depending on the clinical situation these characteristics can offer benefits and disadvantages. Both systems are documented and their indication, advantages and restrictions are discussed with clinical relevance.

Astrid Marinello, Klagenfurt, Alpen-Adria-Univ., Dipl.-Arb., 2010

Various attachments are available to retain overdentures on natural roots or implants. Technical aspects, the clinical handling, the capability to adapt or repair and the costs are parameters to be considered when choosing the appropriate attachment. Ball attachments and bars are clinically established and well documented. Ball attachments as prefabricated, unsplinted units are easily replaceable and show hygienic advantages, while bars show favorable stability. The Locator is a newer, popular clinical alternative to these established attachments. The ball attachment and the Locator are compared from a technical and clinical point of view.

Different materials and methods can be used for edentulous maxillae rehabilitations. A precise fit between the implant and the framework is assumed. Hence, often implant suprastructures made by conventional lost wax techniques lack such a fit and a secondary modification is necessary. Alternatively the CNC-milling technique provides implant frameworks with a passive fit made of titanium and recently also of zirconia. This article describes the fabrication of a fixed complete dental prosthesis supported by seven implants in an edentulous maxilla. Two prostheses were fabricated, one made of a titanium framework veneered with resin and one made experimentally of a zirconia framework veneered with ceramics. The clinical and technical steps are documented and discussed.

In this prospective clinical study on 40 patients with similar clinical conditions (edentulous jaw with 2 interforaminal implants) commercially available ceramic ball attachments (ruby) were compared to commercial titanium ball attachments. The primary aim of the study was to measure the wear of the ball attachments after being 1 year in function. However, in the course of the study already after 7 to 12 months multiple failures with ceramic ball attachments occurred. Twelve (28%) of 43 ceramic ball attachments had to be replaced, mostly because of fractures (8) of the ceramic ball. It seems that ceramic ball attachments of the investigated design are not able to withstand normal intraoral stresses. The short-term susceptibility to fractures didn't allow to examine the ceramic-inherent features such as compressive strength and wear resistance. Furthermore, a secure connection between a titan base and a ceramic ball seems to be challenging. Based on these results, in implant-retained removable prosthesis the use of metal-based retainers is still recommended, although during maintenance a higher wear has to be expected. This wear can be compensated by either activating or changing the matrix or the patrix.

An improvement of prognosis after tumour therapy as well as a rather high number of multiple traumas in the craniofacial area imply a high treatment need for craniofacial tissue defects. For a successful rehabilitation of these individuals, reconstructive oral and maxillofacial surgery and prosthodontics must collaborate closely and synergistically. Besides medical and psychological findings, functional and esthetical aspects need to be taken into account. In this case report the prosthetic reconstruction of a patient with a tooth-supported telescopic defect prosthesis in the maxilla and with a multiple-unit implant-supported fixed prosthesis plus two full ceramic crowns in the mandible is shown. The prosthetic solution was indicated after maxillofacial reconstruction due to the consequence of a suicide attempt.

Removable partial dentures and complete dentures are still an important part of the daily prosthetic work of dentists and dental technicians. Thereby the esthetic design of conventional fixed restorations is challenging the dentist and the dental technician in removable prosthodontics. The result is mainly influenced by the clinical and technical procedure as well as by the choice of material. In this article, the reconstruction of a patient with a complete removable dental prosthesis in the upper jaw and an overlay denture on four telescopes in the lower jaw is presented.

In modern reconstructive dentistry, practitioners delivering removable or fixed dentures still face problems when determining prospective tooth arch and tooth positions. Certain anatomical planes and reference lines, such as Camper's plane, interpupillary axis, etc. have been established as a guide. However, the ability and experience of the dentist remain essential. Adjusting the tooth arches is time-consuming and, therefore, expensive. To simplify and standardise the procedure, dental technicians and dentists may use the Staub Cranial System. It consists of three devices (Positionierer Ortho 1A, Einbaustativ Ortho 2A and Cranialstativ Ortho 3A) and the Staub Cranial software. With its aid, dental casts are surveyed and a penta-area is calculated. This penta-area, three-dimensionally adjusted, may define exactly the site and position of the dental arch. In this article, the Staub Cranial System is presented and documented by a clinical case.

Despite comprising one of the routine duties of dental practitioners, the methods used for the determination of the vertical and horizontal jaw position differ considerably from dentist to dentist. For the overwhelming majority of patients, however, the techniques generally applied for the maxillomandibular relationship record appear to lead to acceptable results. No method seems to be clearly superior to the other. As far as the determination of the horizontal mandibular position (centric relation interocclusal record) is concerned, bimanual manipulation has shown to be particularly reliable. The decisive factor, apart from any preferred method, is that the chosen therapeutic mandibular position be reproducible for both the treatment provider as well as the patient.

The aim of the current study was to gather information about time and etiology of tooth loss, and to analyze the reasons for treatment needs with a questionnaire used among edentulous patients. 60 patients (age 44-98 years) who requested dental treatment were included. More than half of the patients were edentulous before the age of 60, in almost all cases the maxilla was affected first. This difference was more pronounced in women, who experienced tooth loss in the maxilla 17 years prior to the mandible. At the time of edentulism women were about ten years younger than men. According to patients'report, periodontal disease was the most common reason for tooth loss. In the mandible, prosthesis retention was influenced by alveolar ridge resorption, while in the maxilla there was no relation between the amount of resorption and perceived retention. This indicates that maxillary prostheses retention is influenced by other factors besides the alveolar ridge morphology. So, permanent intake of drugs potentially causing xerostomia was related to poorer assessment of prostheses retention in the upper jaw. The results of the questionnaire "Patient satisfaction related to prosthetic restoration" before treatment indicated that the general satisfaction with the existing complete denture in the mandible was influenced by functional problems and the impairment of patients'self-confidence (R-squared = 0.754). The main reason for requesting treatment was the poor retention of the lower denture. More than half of the participants stated that they refrained from eating certain foods due to a reduced chewing ability.

The aim of the present study was to investigate patients' satisfaction with removable implant restorations with two or four implants compared to a complete denture (CD) in the edentulous mandible. 20 patients in each group were asked to fill out a questionnaire ("Patient satisfaction related to the prosthetic restoration") before treatment, after six months and three years. With implant restorations, either implant-retained (IRET) or implant-supported (ISUP), greater improvements in prostheses retention and pain reduction were achieved in comparison to complete dentures. In addition, restrictions related to food selection were resolved for most implant patients. Despite great inter-individual differences, there was a tendency for larger improvements of almost all parameters with IRET, except chewing ability, which was rated best with ISUP. Long-term results revealed that patients with ISUP (four implants) assessed prostheses retention with the highest ratings compared to those with IRET and CD (p = 0,0147). These results indicate that an improvement in functional and psychological parameters can be achieved with two implants, whilst stabilization with four implants improves prosthesis retention, chewing ability and pain reduction in the long term. Maintenance efforts were more complex for implant restorations than for CD and imply a recall at least once a year.

Procera AllCeram is one of the all-ceramic systems with an aluminium-oxide core employing CAD/CAM technology. The aim of the current study was to investigate the fracture resistance of Procera AllCeram full-ceramic crowns with a reduced core design compared to the conventional method. In addition, a possible influence of the preparation form (molars or premolars) and the cementation material (glas-ionomer or composite) was analyzed. For both preparation forms, 30 ceramic cores with reduced margins (collarless cores, test) and 30 cores with extended cores (control) were veneered with porcelain in a standardized procedure (total 120 crowns). For the test group, Procera-AllCeram-margin ceramic material was used for the porcelain collar. 40 crowns each were cemented on stainless steel dies with either Ketac-Cem Aplicap or Panavia F. The additional 40 crowns were set on polyurethane dies without cementation and occlusally loaded until fracture occurred. Among the molar crowns, no differences were observed in fracture resistance neither for the different core designs (test or control) nor for the cementation materials. For the premolar form, fusing of a porcelain margin was associated with a reduction in fracture resistance, while the use of composite cement was accompanied with an increase. The present in vitro results indicate that for Procera AllCeram crowns with a highly undulating preparation margin, a conventional core design combined with adhesive cementation is preferable, especially in the posterior region due to higher chewing forces; this assumption needs to be proven in clinical studies.

Conventional retainers for removable prostheses are frequently used in the daily practice. Financial limits, physical and mental restrictions especially among elderly or disabled patients, and/or limited prognosis of abutment teeth may require simple and less expensive alternatives. For these indications the well-established Dalbo-Rotex-retainer and the newly developed Ticap-system are available. Both systems are options for the anchorage of removable prostheses. Their clinical use is presented; furthermore their advantages and restrictions are discussed.

A case presentation documents the prosthetic treatment of a denture in the upper jaw, and a conventional tooth--supported as well as a combined tooth--implant--supported fixed partial denture in the lower jaw.

The goal of the present study was to measure attachmentlevel changes in patients of 12-48 years of age whose maxillary incisors have been intruded during an orthodontic treatment lasting between 9 and 14 months. Clinical parameters such as clinical probing depth, clinical attachment level and bleeding on probing were evaluated. The results show that i) the intruded teeth gained an average of 0.6 mm of clinical attachment, while the control teeth showed a stable attachment level and ii) the clinical probing depth remained stable at test and control teeth. It was concluded that orthodontical intrusion of maxillary front teeth in patients with a high level of oral hygiene maintains stable periodontal parameters and may even lead to a small clinical attachment gain.

Necrotizing ulcerative gingivitis (NUG) and necrotizing ulcerative Periodontitis (NUP) share many clinical and etiologic characteristics. Both forms are characterized by necrotic gingival tissues, bleeding and pain. Malodor and malaise may be also present. NUG is an infection limited to the gingiva whereas NUP also involves the attachment apparatus. Predisposing factors may include immune dysfunction, poor oral hygiene, cigarette smoking and emotional stress. NUG and NUP might possibly be different stages of the same infection. This case report shows the successful treatment of a patient suffering from NUP.

The aim of this investigation was to evaluate the fracture resistance of three-unit fixed partial dentures manufactured with the Procera-System in vitro. Metal abutments representing the teeth 25 and 27 were prepared with a 90 degrees circumferential internally rounded shoulder. The abutments were duplicated with polyvinysiloxane, and master dies were fabricated. Using the Procera-System, 21 aluminiumoxid frameworks were manufactured. Twelve of these were veneered with porcelain in a standardized manner. All non-veneered and veneered frameworks were cemented on the original metal abutments and loaded to fracture. The mean fracture loads of the non-veneered and veneered frameworks were 477 N and 645 N, respectively. The Weibull modules of the test series were 4.7 for the non-veneered and 4.0 for the veneered frameworks. The in vitro results of this investigation seem to indicate that the use of fixed partial dentures manufactured with the Procera-System are clinically questionable. Furthermore, the low Weibull modules point to a limited fracture predictability. Assuming that chewing forces up to 600 N may occur in the molar region and loading of dental ceramics causes fatigue and weakening over time, the clinical application may not be recommended.

Poor metabolic control of diabetes mellitus has often been associated with the severity of periodontal disease. This case report describes the diagnosis, therapeutic concept, treatment steps, and long-term monitoring of a 22-year-old female with generalized aggressive periodontitis who had a history of type 1 brittle diabetes mellitus. The main objective was to treat the patient with periodontal surgery despite the difficult baseline situation to avoid tooth loss that would have been accompanied by a need for prosthodontic treatment. The mean of glycosylated hemoglobin [figure: see text] measurement (HbA1c) was used to indicate the long-term control of diabetes mellitus. This report proves the efficiency of periodontal therapy in the prevention of future periodontal breakdown and improvement of the HbA1c level in a systemically compromised patient.

The aim of this study is to report about the dental health situation in Switzerland and to evaluate frequencies of dental visits. Data were obtained from the first and second national Health Survey of the Federal Office for Statistics in 1992/3 and 1997. Based on a random sample of the population aged from 15 to 74 years, 71% participated in an oral interviews and of this group of individuals, 75% later filled in a written questionnaire in 1992/3. Data analysis showed that the proportion of the fully dentate population (28 remaining teeth) is 41%, while almost 50% had some prosthetic treatment. 31% were treated with fixed prostheses, i.e.crowns and/or bridges, and 19% with removable prostheses, i.e. partial and/or full dentures. With increasing age the number of missing teeth and the frequency of prosthetic treatment went up. The population with prosthodontic reconstruction increased mainly in the third and forth decades. In the elderly population (age 65-74 years), a shift was observed from fixed to removable prostheses; two thirds in this groups was restored with removable prostheses. The proportion of subjects visiting the dentist was by 70% in 1992/3 and declined to 65% in 1997. Subjects wearing removable prostheses had apparently lower frequencies (43%) in dental visits than subjects with fixed prostheses (80%). A potential concern exists for the edentulous population who presented a limited need for dental visits of only 22% during the year preceding the study.

The goal of the questionnaire was to determine the materials and methods that general dentists in Switzerland at present use for the treatment of non-vital abutment teeth. Questionnaires were sent to 1000 dentists from a computer generated random sample of the list of members of the SSO (Swiss Dental Society). The return ratio was 36%. The responses provided information on the current philosophies and prevailing techniques used to restore endodontically treated abutment teeth. Most of the answering dentists believed it was necessary to stabilize a root treated tooth with a post. The preferred restoration in anterior teeth was the cast post and core, while composite resin build-up with a prefabricated post was predominantly made for posterior teeth. Conical or combined cylindrical-conical posts, which had a sand-blasted surface, were predominantly used. Most of the answering dentists strove to stabilize the remaining tooth structure by circular enclosure of the tooth structure by the later crown (ferrule effect). Zinc phosphate cement was still preferred for cementation of metal posts and ceramic posts were most often fixed with the help of the acid etching technique. The most frequently described failures were retention loss or root fractures.

The purpose of this article is to draw attention to the possible complications of foreign body ingestion or aspiration associated with dental treatment, especially oral implant treatment. A guide for the management of swallowed or inhaled objects is given. When the object cannot be coughed out, then it is mandatory to take frontal and lateral chest roentgenograms to identify the object's position in the intestinal system or in the tracheobronchial tree. In case of ingestion, attempts should be made to recover the foreign object by esophagoscopy. Aspirated foreign bodies should be removed within 24 hours. Acute obstruction can be life threatening and delaying the removal of foreign objects may make a bronchoscopy technically more difficult. The clinician must be aware of the complications involved in accidentally inhaling or ingesting foreign bodies during dental treatment. Patients at greater risk of swallowing or aspirating foreign objects need to be identified and extra preventive steps must be taken to avoid such complications.

The aim of this article was to present the CAD/CAM-assisted Procera system as a new all-ceramic full-coverage crown system. New technologies need to be evaluated technically and clinically to be able to fulfill the requests for aesthetics, physical strength and biocompatibility when restoring the anterior and posterior region. The Procera AllCeram system offers the opportunity to fabricate densely sintered, high-purity, tooth-colored copings. Mechanical properties of the Procera alumina coping, indications and contraindications and additional applications are discussed. The clinical and technical procedures and any specific limitations and peculiarities are summarized and documented with clinical cases in a step-by-step illustration.

In a combined retrospective longitudinal study an evaluation of different dental and periodontal indexes (tooth mobility, probing pocket depth, plaque index, sulcus bleeding index, probing attachment level) in 62 patients with 77 resin-bonded bridges was performed. The direct comparison between test (abutment) and control (non-abutment) teeth revealed no differences at the day of evaluation in comparison to the date of incorporation. The longitudinal evaluation resulted in more favourable values at the day of evaluation in comparison to the date of incorporation for both the test and control teeth. Despite the altered contour of the abutment teeth, resin-bonded bridges seem not to change the periodontal status in a long-term evaluation, if good patient cooperation and regular care by a dental hygienist are guaranteed.

788 patients with 3-unit resin-bonded bridges were followed up over a time period of up to 5 years after placement. In this multicenter study, the following clinical variables were analyzed: caries, periodontal disease, loss of pulp vitality and the behavior of the dental materials involved were assessed. Adverse findings were rare. More data are needed over a longer period of time to support the present results.

An evaluation of about 300 abutment teeth of resin-bonded bridges (Rochette, electrochemically etched) and resin-bonded extracoronal attachments was performed to determine the surface area and the length of the circumference of the retainers. By using a combined indirect (preparation of the specimen) and direct (automatic image analysis) method for the determination of both parameters a mean value of 50 mm2 for the surface area and 30 mm for the circumference, respectively, was evaluated. In addition, two indices (loading-index (BI): sigma surface area/width of pontic tooth; moisture penetration-index (FPI): sigma surface area/sigma circumferences) as predictors for the longevity of resin-bonded reconstructions were calculated. The loading-index was a good predictor for successful reconstructions: the clinical success was the better, the bigger the retention area, and the smaller the circumference of the retainer and the smaller the pontic tooth.