3D printing of ultra-thin veneers made of lithium disilicate using the LCM method in a digital workflow: A feasibility study.

OBJECTIVE: This article highlights the feasibility of the additive fabrication of ultra-thin veneers made of lithium disilicate using the lithography-based ceramic manufacturing (LCM) method. CLINICAL CONSIDERATIONS: An esthetical appealing restoration of anterior teeth with thin ceramic veneers is considered one of the ultimate challenges in restorative dental prosthetics. These sophisticated restorations can be fabricated in different ways. Both analog and digital subtractive manufacturing processes have been used to date. Either of the methods is highly demanding for the dental technician and dental engineering due to the required low ceramic layer thickness. CONCLUSION: Modern additive manufacturing methods, for example LCM technology, enable the production of ultra-thin lithium disilicate veneers with layer thicknesses of down to 0.2 mm and could therefore represent a viable alternative for this indication in the future. CLINICAL SIGNIFICANCE: Digital technologies can help streamline workflows, make the outcome more predictable and reproducible, and even further optimize therapeutic restorative options such as highly esthetic veneers for anterior teeth. The reduced material thickness allows for a true non-prep solution or minimally invasive preparation.

Impact of different types of dental prostheses on oral-health-related quality of life: a prospective bicenter study of definitive and interim restorations.

PURPOSE: To assess the impact of different types of dental prostheses, including definitive and interim restorations, on oral health-related quality of life (OHRQoL) before and after prosthetic treatment. MATERIALS AND METHODS: A total of 151 patients received prosthetic treatment at one of two German departments of prosthetic dentistry. The patients' OHRQoL was assessed using the German version of the Oral Health Impact Profile (OHIP-G53) at baseline (T0) and at 1 week (T1) and 3 months (T2) after treatment. Patients were divided into 10 subgroups according to their pre- and posttreatment status. The effect of the type (no prosthesis; fixed prosthesis; removable prosthesis) and duration of wear (definitive; interim) of the restorations was evaluated. Results were analyzed using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests with a significance level of P = .05. RESULTS: The highest OHRQoL was recorded for patients with fixed restorations, as indicated by the fact that their OHIP scores were lowest. A significant improvement in OHRQoL (P ≤ .034) was observed for patients who needed prostheses and were then treated with removable or fixed restorations. The OHIP score was affected by a change in restoration type. Rehabilitation with definitive prostheses had a significant effect on posttreatment OHRQoL (P ≤ .006). CONCLUSION: In general, prosthetic rehabilitation by use of fixed or removable prostheses resulted in an improvement in OHRQoL. The use of the same type of restoration before and after treatment had a positive effect on OHRQoL. If possible, a change of restoration type should be avoided. For patients who require permanent prostheses, the use of fixed and removable restorations is recommended. For oral rehabilitation, fixed restorations should be preferred in order to achieve best possible improvement of OHIP score.

Accuracy, Reliability and Clinical Implications of Static Compared to Quantifiable Occlusal Indicators.

OBJECTIVE: This literature review summarizes the properties, advantages, limitations, and clinical implications of employing static occlusal indicators compared to quantifiable digital occlusal indicators during occlusal adjustments. METHOD: An electronic database search of dental literature was carried out in PubMed/MEDLINE using the key words Occlusal Indicators, Occlusal Assessment, Static, Reliability, Dynamic, Repeatability, Validity and Clinical Accuracy. A total of 231 papers were isolated, with 129 papers considered for review. RESULTS: The included papers were grouped by Static and Dynamic Occlusal indicators. The numbers of papers in the Static Group was extremely low (only 20 papers) compared to The Dynamic group (T-Scan: 89; Dental Prescale: 28; Intraoral Scanners:17). CONCLUSION: Little evidence supports the use of static occlusal indicators due to their high degree of subjectivity required during implementation. However, much scientific evidence supports the use of T-Scan, as it measures relative occlusal forces and timing objectively, accurately, and repeatedly. For the improvement of Occlusal Practice, Subjective Interpretation using Static occlusal indicators should be replaced with digital ones for objective measurements. CLINICAL RELEVANCE: The computerized occlusal analysis system is well studied and has the capacity to provide precise time and force sequencing information to objectively evaluate occlusal contacts for improved treatment outcome.

Oral health-related impact profile of patients treated with fixed, removable, and telescopic dental prostheses in student courses-a prospective bicenter clinical trial.

OBJECTIVES: To analyze the oral health-related impact profile in patients treated with three different types of dental prosthesis in student courses. MATERIALS AND METHODS: This prospective bicenter clinical trial was conducted with 151 patients being treated with fixed (n = 70), removable (n = 61), or telescopic dental prostheses (n = 20) in clinical student courses of two German universities from October 2018 to October 2019. All patients completed three standardized German versions of the Oral Health Impact Profile (OHIP-G49/53) before prosthetic treatment (T0), at control after 1 week (T1), and after 3 months (T2), divided into five dimensions: (a) appearance, (b) oral function, (c) psychosocial impact, (d) linguistic limitations, and (e) orofacial pain. Data were analyzed with Kolmogorov-Smirnov, Wilcoxon signed-rank, Kruskal-Wallis, Mann-Whitney, and Cronbach's alpha tests. RESULTS: Within T0-T1 and T0-T2, greater improvements were determined for removable compared with fixed dental prostheses for the dimensions' oral function (p ≤ 0.014), linguistic limitations (p ≤ 0.016), and appearance (p ≤ 0.003). No significant differences were found between fixed and telescopic dental prostheses (p ≥ 0.104) or between removable (partial dental prosthesis with clasps and complete dental prosthesis) and telescopic dental prostheses (p ≥ 0.100). Within T1-T2, a significant improvement in orofacial pain could be determined (p = 0.007). CONCLUSIONS: Restorations presented an improvement in oral health-related quality of life. Removable dental prostheses showed better improvement than fixed ones in various dimensions. CLINICAL RELEVANCE: Knowledge about the influence of oral health-related quality of life on the three different types of prosthesis used in student courses can be of decisive help in dental consultations.

Clinical performance of occlusal onlays made of lithium disilicate ceramic in patients with severe tooth wear up to 11 years.

OBJECTIVES: Evaluation of survival and complication rate of monolithic occlusal onlays made of lithium disilicate ceramic used in patients with severe tooth wear up to 11years of clinical service. METHODS: In a prospective non-randomized clinical study 7 patients (4 male, 3 female; median age: 44.3±6.56years old) were restored full mouth with a total of 103 adhesively bonded occlusal onlays made of lithium disilicate ceramic (IPS e.max Press, Ivoclar Vivadent, Schaan, Liechtenstein). All restorations were examined during annual recall visits using periodontal parameters according to the modified United States Public Health Service (USPHS) criteria: (a) marginal discoloration, (b) secondary caries, (c) marginal integrity, (d) surface texture, (e) restoration fracture, and (f) occlusal wear, rating with Alpha, Bravo and Charlie over an observation period up to 11years (68-139 months; median: 94.9±26.1 months). Data was statistically analyzed using the Kaplan-Meier estimation. RESULTS: Monolithic lithium disilicate occlusal onlays presented a 100% survival rate. Four restorations within one patient (3.9%) presented marginal discoloration, one after 60 and three after 108 months (all rated Bravo). One restoration (1%) showed a marginal crack formation (technical complication) after 120 months, rated Bravo. No biological complication, debonding or secondary caries could be found and tested periodontal parameters showed excellent results. SIGNIFICANCE: Based on the analyzed data up to 11years, monolithic occlusal onlays made of lithium disilicate ceramic can be considered as a reliable treatment option for full-mouth rehabilitations in patients with severe tooth wear.

Historical development of root analogue implants: a review of published papers.

The timetable for placing a dental implant can be crucial in the reduction of resorption of the socket after an extraction. The association of immediate implantation with an implant that copies the anatomy of the extracted root seems to add benefits in limiting the hard and soft tissue changes that may occur. The purpose of this paper is to provide an overview of the historical development of all types of root analogue implants from their beginning to the present day. To our knowledge the first individualised ones were described in 1969. Later, the use of titanium instead of the polymers that were used to start with offered better bony integration, and showed that the selection of materials was a key factor in their success. Root analogue implants made from zirconia were also described when attempts were being made to improve aesthetics in the anterior regions. The more recent introduction of digital technology such as DICOM has allowed the fabrication of these implants in less time, and the combination with digital diagnostic options such as cone-beam computed tomography facilitated the fabrication of some types of implants before extraction that could be inserted immediately into the alveolar socket with optimal and safe 3-dimensional positioning. Currently digital planning allows the clinician to design the ideal implant and abutment, which reduces the need for tissue grafting in the surgical phase and gingival conditioning in the prosthetic phase.

Oral health-related impact profile in full-mouth restored patients with two different tooth-colored restoration materials.

OBJECTIVES: To analyze the change of oral health impact profile (OHIP) in patients with full-mouth rehabilitations due to moderate/severe tooth wear dependent on different restorative materials (ceramic/experimental CAD/CAM composite). MATERIALS AND METHODS: Twenty-nine healthy patients (15 male/14 female, age 44.6 ± 28.4 years) requiring full-mouth rehabilitation due to different degrees of tooth wear were instructed to fill the German version OHIP-G49 questionnaire before (baseline) and 30 days after prosthetic treatment with ceramic (n = 17) or experimental CAD/CAM composite (n = 12) restorations. Questions were divided into five dimensions: appearance, oral functions, psychosocial impact, linguistic limitations, and orofacial pain; changes between both OHIP-questionnaires for each question and patient were dissected by difference values, separately. Data were analyzed with the Kolmogorov-Smirnov, Wilcoxon's signed-rank, Kruskal-Wallis, Mann-Whitney, and Cronbach's alpha tests (significance level p = 0.01). RESULTS: The appearance dimension showed the highest results (p < 0.001, 100% improvement with all values > 0); the linguistic limitations dimension presented the lowest improvement (p < 0.001). The other three dimensions were not statistically different. No statistical differences between the two materials depending on OHIP questionnaire results occurred. CONCLUSIONS: The esthetic appearance of the patients was influenced positively by full-mouth rehabilitation, irrespective of the material used. Improvements were also made in the parameters "toothache" and "problem of food intake." No statements could be made for the parameter "language." CLINICAL RELEVANCE: With an increasing number of patients with moderate/severe tooth wear, thorough knowledge about the improvement of OHIP is important. This information is advantageous for the consultation and handling of patients when complex treatments are planned.

Systematic development of esthetics and function in a young patient with maxillary dental aplasia.

OBJECTIVES: Full-arch rehabilitations in young patients suffering from dental agenesis should compensate for the reduced vertical dimension of occlusion and restore both esthetics and function at minimal biological cost. This requires precise planning and maximum patient compliance during the preprosthetic phase. The pretreatment period with tooth-colored splints promotes a predictable outcome of the final restorations. Clinical considerations: Thanks to better restorative materials and adhesive techniques and increased knowledge of how to preserve sound tooth structures, prosthetic dentistry has increasingly turned toward minimally invasive procedures. The present clinical case documents a minimally/non-invasive maxillary full-arch rehabilitation of an agenesis patient with multiple dental aplasia, primary tooth persistence, and deficits in bone growth. The patient was pretreated with a tooth-colored CAD/CAM polycarbonate splint. Adequate esthetics and function were achieved by two zirconia-based single-wing adhesive fixed dental prostheses to replace the upper lateral incisors, lithium disilicate ceramic partial crowns for the posterior regions, and two feldspathic veneers for the upper central incisors. CONCLUSIONS: Non-invasive pretreatment with a removable tooth-colored splint realizes the treatment goal simply and safely, reduces treatment time, increases predictability, and facilitates the transfer of the prototype to the final restorations. New restorative options permit the minimally invasive treatment of such patients. CLINICAL SIGNIFICANCE: A pretreatment with a removable tooth-colored splint offers a simple and safe way to define the treatment goal, reduces treatment time, increases predictability, and facilitates the transfer of the results to the final restorations even in complex cases. New restorative options permit minimally invasive treatments of young patients with multiple dental agenesis.

Histo-anatomic 3D printing of dental structures.

The creation of dental restorations with natural appearance and biomechanics represents a major challenge for the restorative team. The manufacturing-process of high-aesthetic restorations from tooth-coloured restorative materials is currently dominated by manual manufacturing procedures and the outcome is highly dependent on the knowledge and skills of the performing dental technician. On the other hand, due to the simplicity of the manufacturing process, CAD/CAM restorations from different material classes gain more and more acceptance in the daily routine. Multi-layered restorations show significant aesthetic advantages versus monolithic ones, but are difficult to fabricate using digital technologies. The key element for the successful automated digital fabrication of aesthetic anterior restorations seems to be the form of the individual dentine core as defined by dentine enamel junction (DEJ) covered by a more transparent layer of material imitating the enamel layer to create the outer enamel surface (OES). This article describes the possibilities and technologies available for so-called '4D-printing'. It introduces the digital manufacturing process of multilayered anterior teeth using 3D multipart printing, taking the example of manufacturing replicas of extracted intact natural teeth.

Composite Resin Core Buildups With and Without Post for the Restoration of Endodontically Treated Molars Without Ferrule.

OBJECTIVE: The aim of this study was to investigate the restoration of highly damaged, broken-down endodontically treated molars without the ferrule effect using glass ceramic crowns on different dual-cure composite resin core buildups. METHODS AND MATERIALS: Thirty (N=30, n=15) decoronated, endodontically treated teeth (no ferrule) were restored without a ferrule with a direct buildup using the dual-curing composite Multicore HB (group MHB) or the dual-curing composite core buildup Multicore Flow in combination with glass-fiber-reinforced composite post (FRC post; group MFP). All teeth were prepared to receive bonded glass ceramic crowns (Empress CAD luted with Variolink II) and were subjected to accelerated fatigue testing. Cyclic isometric loading was applied to the palatal cusp at an angle of 30 degrees and a frequency of 5 Hz, beginning with a load of 200 N (×5000 cycles), followed by stages of 400, 600, 800, 1000, 1200, and 1400 N at a maximum of 30,000 cycles each. Specimens were loaded until failure or to a maximum of 185,000 cycles. Groups were compared using the life table survival analysis (log rank test at p=0.05). Average fracture loads and number of survived cycles were compared with one-way analysis of variance (Scheffé post hoc at p=0.05). Previously published data from the same authors about core buildups made of high-performance polymers (group HPP, n=15) and light-curing composite resin without FRC posts (group TEC, n=15) and with FRC posts (group TECP, n=15) using the same experimental setup were included for comparison. RESULTS: None of the tested specimen withstood all 185,000 load cycles. There was no significant difference in mean fracture load (p=0.376), survived cycles (p=0.422), and survival (p=0.613) between MHB (facture load 859.4 N±194.92) and MFP (796.13 N±156.34). Group HPP from a previous study appeared to have significantly higher performance than all other groups except MHB. All groups with posts were affected by an initial failure phenomenon (wide gap at the margin between the buildup/crown assembly and the root). CONCLUSIONS: HPP and MHB enhanced the performance of all-ceramic leucite-reinforced glass ceramic crowns, and insertion of a fiber-reinforced composite post was not influential when using other materials.

CAD/CAM Polymer vs Direct Composite Resin Core Buildups for Endodontically Treated Molars Without Ferrule.

OBJECTIVES: The aim of this study was to investigate the restoration of broken-down endodontically treated molars without ferrule effect using glass ceramic crowns on different composite resin core buildups. METHODS AND MATERIALS: Forty-five decoronated endodontically treated teeth (no ferrule) were restored with a semidirect buildup using an experimental computer-aided design/computer-aided manufacturing (CAD/CAM) high-performance polymer (HPP group) or with light-curing composite core buildups of Tetric EvoCeram with (TECP group) or without (TEC group) a glass-fiber-reinforced post. All teeth were prepared to receive bonded glass ceramic crowns (Empress CAD luted with Variolink II) and were subjected to accelerated fatigue testing. Cyclic isometric loading was applied to the palatal cusp at an angle of 30° and a frequency of 5 Hz, beginning with a load of 200 N (×5000 cycles) and followed by stages of 400, 600, 800, 1000, 1200, and 1400 N at a maximum of 30,000 cycles each. Specimens were loaded until failure or to a maximum of 185,000 cycles. Groups were compared using the life-table survival analysis (log rank test at p=0.05). Average fracture loads and number of survived cycles were compared with one-way analysis of variance (Scheffé post hoc at p=0.05). RESULTS: None of the tested specimen withstood all 185,000 load cycles. There was a significant difference in mean fracture load, survived cycles, and survival; the HPP group (fracture load 975.27N±182.74) was significantly higher than the TEC (716.87N±133.43; p=0.001) and TECP (745.67±156.34; p=0.001) groups, and the TEC and TECP groups showed no difference (p=0.884). Specimens in the TECP group were affected by an initial failure phenomenon (wide gap at the margin between the buildup/crown assembly and the root). CONCLUSIONS: Semidirect core buildup made from high-performance polymer enhanced the performance of all-ceramic leucite-reinforced glass ceramic crowns compared with direct light-curing composite resin buildups. The use of a fiber-reinforced post system did not influence the fatigue strength of all-ceramic crowns.

Enhancing the predictability of complex rehabilitation with a removable CAD/CAM-fabricated long-term provisional prosthesis: a clinical report.

Implementing any definitive prosthetic treatment of the residual edentulous ridge involves several risks. The patient's expectations may not be completely fulfilled as such treatment procedures include major changes in function and esthetics. Innovative materials, such as high-density polymers based on a highly cross-linked polymethylmetacrylate (PMMA) or composite resin for CAD/CAM-manufacturing are an alternative treatment option. They enhance the predictability of complex rehabilitations, especially in situations where the prognosis of the residual ridge behavior over time is challenging. This article describes an innovative approach of an extended pretreatment phase by using intraoral scanning and CAD/CAM technology for the fabrication of a long-term provisional removable dental prosthesis made of high-density polymer.

Description and evaluation of a new approach on pre-clinical implant dentistry education based on an innovative simulation model.

INTRODUCTION: Predominantly theoretical courses are employed to teach German dental students in implant dentistry at pre-clinical stage. As implant dentistry is an important part of the clinical treatment spectra, practical implementation of this field at an early stage of education seems to be appropriate. By a newly developed interdisciplinary implant dentistry course, students should assess an improved competence level as well as first practical experiences in the field of implant dentistry at the pre-clinical stage of their education. MATERIALS AND METHODS: Interdisciplinary implant dentistry education was integrated in the final pre-clinical course Phantom II at the Department of Prosthodontics, LMU, Munich. In total 120 pre-clinical students participated at the implant dentistry education course. After theoretical introduction into implant surgery and implant prosthetics, 30 simulation units were employed for the practical training of the participants. All important treatment steps were carried out by the students under instruction by the supervisors, including interdisciplinary planning, the use of the drilling template, the template guided insertion of two implants, as well as the integration of two ball attachments into a pre-existing full denture. After the course participants were asked by questionnaire about the quality of the course and their personal opinion. RESULTS: The course received an extraordinary positive feedback. In total 108 students evaluated the course with the overall grade of 1.68 according to the German school-mark system (1 = excellent, 6 = unsatisfactory). Also the single parts of the course were voted constantly positively. CONCLUSION: The aim of this first interdisciplinary course for pre-clinical students was to enhance competence level and practical implementation of implant dentistry at an early stage of education. Participants' comments and suggestions on the questionnaires demonstrated the positive response and the general interest in this form of dental education, as well as the demand for further development of training in this field.

Digital dentistry: an overview of recent developments for CAD/CAM generated restorations.

As in many other industries, production stages are increasingly becoming automated in dental technology. As the price of dental laboratory work has become a major factor in treatment planning and therapy, automation could enable more competitive production in high-wage areas like Western Europe and the USA. Advances in computer technology now enable cost-effective production of individual pieces. Dental restorations produced with computer assistance have become more common in recent years. Most dental companies have access to CAD/CAM procedures, either in the dental practice, the dental laboratory or in the form of production centres. The many benefits associated with CAD/CAM generated dental restorations include: the access to new, almost defect-free, industrially prefabricated and controlled materials; an increase in quality and reproducibility and also data storage commensurate with a standardised chain of production; an improvement in precision and planning, as well as an increase in efficiency. As a result of continual developments in computer hardware and software, new methods of production and new treatment concepts are to be expected, which will enable an additional reduction in costs. Dentists, who will be confronted with these techniques in the future, require certain basic knowledge if they are to benefit from these new procedures. This article gives an overview of CAD/CAM-technologies and systems available for dentistry today.

Retention of selected core materials to zirconia posts.

Due to their favorable optical and mechanical properties, endodontic posts made of partially stabilized zirconia ceramic (ZrO2-Y2O3) are a promising alternative to those made of metal. Zirconia posts can be combined with various tooth-colored core materials to increase the optical properties of a final esthetic restoration. For stability, a reliable bond between core material and the post should be generated. This in vitro study evaluated the retention of selected core materials to zirconia posts dependent on different surface treatments and bonding procedures. Two types of zirconia posts (CeraPost [CEP], Lemgo, Germany) and CosmoPost [COP], Ivoclar Vivadent, Amherst NY 14228, USA) were employed for the study. Ring-shaped cores were fabricated of either heat-pressed, zirconia-containing glass ceramic (IPS Empress Cosmo [EMC], Ivoclar Vivadent), highly-filled hybrid composite (Tetric Ceram [TEC], Ivoclar Vivadent) or an experimental, high-strength glass ceramic (OHSU-RWTH [EX], Ivoclar Vivadent). The core made of material EX was either directly heat pressed (EXP) or adhesively bonded (EXB) onto the post using a flowable composite. Prior to core application, the post surfaces were preconditioned by alumina abrasion (AA) or tribochemical silicoating and silanation (TCS). Specimens (10 per group) were stored in artificial saliva (pH 5.2) for 150 days. Storage time included 5,000 thermocycles (5/55 degrees C per 30 seconds). Defect analysis was conducted visually using a light microscope and a fiber optic transillumination prior to the testing procedure. The loads required to separate post and core were determined by a push-out test. Following testing, the surfaces of the posts and core materials were evaluated in a scanning electron microscope (SEM). There were no statistically significant differences between the separation loads of groups COP/AA/EMC, COP/TCS/TEC, CEP/AA/EMC and COP/AA/EXB. Group COP/AA/EXP showed significantly higher retention, but also the highest standard deviation and the highest number and diversity of severe defects in the core material prior to testing. Similar defects were detected in the group COP/AA/EXC. In group COP/TCS/TEC, where there were a lower number of minor defects, and in COP/AA/EMC and COP/AA/EMC, no defects were observed. For both post systems tested with the combinations alumina abrasion/zirconia-containing glass-ceramic and tribochemical silicoating and silanation/highly-filled hybrid composite, a reliable retention was achieved. The use of the experimental high-strength glass ceramic as a core material is contraindicated due to a discrepancy in the coefficient of thermal expansion to the zirconia-post.

Maxillary sinus augmentation with the xenograft Bio-Oss and autogenous intraoral bone for qualitative improvement of the implant site: a histologic and histomorphometric clinical study in humans.

The aim of the present clinical study was to determine, through histologic and histomorphometric investigations of human bone specimens, whether the addition of autogenous bone to the bone substitute material Bio-Oss can produce a high-quality implant site. To improve vertical bone height, 13 sinus floor elevations were carried out in a total of 12 patients. Augmentation of the maxillary sinus floor was completed using a mixture of Bio-Oss and bone harvested intraorally from the mandibular symphysis, the retromolar space, or the tuberosity region. Following an average of 7.1 months of healing, 36 Brånemark System implants were placed. During this surgical intervention, 23 cylinder-shaped bone biopsies were taken from the augmented maxillary region using trephine burs. Histologic analysis of the bone biopsies revealed that the Bio-Oss granulate was well-integrated into the newly formed bone; 33.1% (+/- 12.4%) of the substitute material surface was in direct contact with bone. Histomorphometric analysis of the samples revealed an average percentage proportion of bone of 18.9% (+/- 6.4%). The bovine substitute material and soft tissue occupied, respectively, 29.6% (+/- 8.9%) and 51.5% (+/- 9.4%) of the measured surface. When the implants were uncovered after an average healing phase of 6 months, all 36 implants had become osseointegrated. The combination of osteoconductive Bio-Oss and osteoinductive autogenous bone thus proved to be a material suitable for application in sinus floor augmentation.

Metal-free inlay-retained fixed partial dentures.

OBJECTIVE: The treatment procedures used in conjunction with two different metal-free restorative systems are illustrated on the basis of clinical examples. In addition, a report on the initial clinical findings is provided. METHOD AND MATERIALS: Metal-free restorative materials are opening doors to new preparation methods because of their close link to the adhesive cementation technique. As a result of the developments over the past few years, various metal-free systems that can be used to fabricate short-span fixed partial dentures (FPD) are now available. Certain guidelines, however, must be observed in the process. Because of their minimal invasiveness, inlay-retained FPDs offer an interesting solution in cases where the residual dentition exhibits low caries activity. Since the beginning of 1997, a total of 23 metal-free inlay-retained FPDs made of two different types of framework material (11 of high-strength pressed ceramic and 12 of fiber-reinforced composite) have been examined in a clinical study. RESULTS: One inlay-retained FPD made of pressed ceramic had to be replaced because of a fracture. Because the materials have only been on the market for a short time, long-term results are not yet available. CONCLUSION: This type of restoration provides excellent esthetics and reduced invasiveness compared with complete crown-retained FPDs, although indications are limited by the special mechanical properties of the material.

Clinical use of an intraoral silicoating technique.

UNLABELLED: A ceramic fracture rate of metal-ceramic fixed prosthodontics of up to almost 9% calls for an efficient and effective intraoral repair system. For the repair of fractured veneering material, an intraoral silicoating technique was introduced. In contrast to other repair techniques, the silicoating can successfully be used on a variety of dental restorative materials and, therefore, offers additional applications in the field of the intraoral adhesive technique. This silicoating technique, consisting of a chairside airabrasion device filled with a specific silica-coated air-abrasion medium, has been used intraorally by the authors since 1993 for clinical purposes. The clinical procedure is described for different applications in the field of the adhesive technique: intraoral repair, preconditioning of core buildups, implant abutments, and surfaces of fixed prosthodontics for the bonding of orthodontic brackets or periodontal splints. CLINICAL SIGNIFICANCE: The intraoral silicoating technique promotes reliable adhesion to the major part of metal alloy, composite, and ceramic surfaces of fixed prosthodontics. Preliminary clinical results of intraoral repairs conducted with this technique have shown that it presents a medium-term alternative to the replacement of the restoration. Also, the preliminary results of the clinical applications in other fields of adhesive dentistry are promising.

Maxillary sinus augmentation using xenogenic bone substitute material Bio-Oss in combination with venous blood. A histologic and histomorphometric study in humans.

The aim of the present study was to evaluate bone formation following maxillary sinus augmentation using bovine bone substitute material Bio-Oss in combination with venous blood by means of histologic and histomorphometric examination of human biopsies. This involved a total of 15 sinus floor elevation procedures being carried out on 11 patients (average age of 49.6 years) according to the technique described by Tatum (1986). The subantral sinus cavity was augmented using bovine apatite combined with venous blood. After an average healing phase of 6.8 months, trephine burrs were used to take 22 bone biopsies from the augmented sinus region. Then 38 Brånemark implants were inserted in both the osteotomies resulting from bone sampling and in regular sites in the augmented posterior maxilla. Histomorphometric analysis of ground sections from the bone biopsies prepared according to the standard method of Donath & Breuner (1982) produced an average percentage of newly-formed bone of 14.7% (+/- 5.0%) and a proportion of residual xenogenic bone substitute material of 29.7% (+/- 7.8%). Some 29.1% (+/- 8.1%) of the surface of the Bio-Oss granulate was in direct contact with newly-formed bone. Histologically, newly-developed bone became evident, partly invaginating the particles of apatite and forming bridges in the form of trabeculae between the individual Bio-Oss particles. Despite the absence of osteoclastic activity, the inward growth of bone indicates slow resorption of the xenogenic bone graft material. When the implants were uncovered, after an average healing phase of 6 months, 4 of the 38 implants had become loose. Of these 4 implants, 1 had to be subsequently explanted, while the others remained as "sleeping implants" and were not included in the implants superstructure. Thus, the resulting clinical survival rate, prior to prosthetic loading, was 89.5%.

Ceramic abutments--a new era in achieving optimal esthetics in implant dentistry.

In the visible dental region in particular, implant-prosthetic restorations filling single-tooth gaps make exacting demands on function and esthetics. One crucial factor influencing the esthetic outcome is the emergence profile of the restoration. The introduction of aluminum oxide or zirconium oxide abutments, which can be milled to meet individual requirements, provides new opportunities for reconstruction adapted to anatomic findings. Tooth-matched coloring combined with customized preparation and dimensioning make for optimal mucogingival esthetics in implant-supported single-tooth restorations. The aim of the present article is to give a general survey and to illustrate the use of ceramic abutments with clinical case reports.