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Aim of this study was to get an overview of what dentists estimate to be the reason for failure of adhesive composite restorations and to gain knowledge about potential future foci for targeted further education. Therefore, a survey about the fabrication of composite restorations was conducted in the course of seven dental conferences with the main topic tooth-prevention. A total of 577 dentists participated in the survey. The most often called estimated factor for failure of composite restorations was the "dentist" (70.7%), followed by "indication" (32.2%), "material" (8.5%) and "patient" (8.1%). Participants estimated insufficient drying and fluid management (67.9%), incorrect application of the adhesive system (41.8%), insufficient lightpolymerisation (31.2%) and errors in incremental technique (27.6%) to be the main mistakes. The participating dentists claimed to attach great importance to careful drying and fluid management (60.8%), thorough adhesive application (37.3%), adequate incremental technique (32.6%) and sufficient lightpolymerisation (28.8%) while placing their own restorations. According to the survey participants, the treating dentist has the greatest influence on the quality and longevity of composite restorations. Drying and fluid management was the most often called estimated reason for failure but at the same time the step which is given the greatest caution.

The aim of this study was to carry out a representative survey on the implementation of and experience with repairs of single-tooth restorations among dentists in the Canton of Zurich, Switzerland. An anonymous questionnaire was sent to all 1,411 dentists registered in the Canton of Zurich; 38.9% of the delivered questionnaires were returned and 35.3% could be evaluated. The statistical analysis comprised Kendall’s rank correlation coefficient (tau), Wilcoxon signed-rank tests, and Kruskal-Wallis tests. The level of significance was set at p≤0.05. Repair restorations are frequently made (composite: 98.5%, ceramic: 88.9%, crowns: 86.5%, metal: 54.6%, amalgam: 51.5%). Main indications for repairs were the partial loss of an existing restoration or of the adjacent dental hard substance, while restoration failures due to secondary caries were repaired to a lesser extent. The decision to repair is largely dependent on the size of the defect (90%), the size of the original restoration (63%), and the material of the failed restoration (84%). Repair restorations are most frequently made with composite following adequate conditioning of the repair surface. A majority of the dentists rate the lifespan of repair restorations as reduced in comparison with newly made restorations. In summary, repairs of defective single-tooth restorations are frequently performed by dentists in the Canton of Zurich, Switzerland, and constitute a well-established treatment procedure.

This study evaluated the fracture loads of different threeunit fixed dental prostheses (FDPs) for temporary restorations. In total, three CAD/CAM materials (VITA CADTemp [CT], Telio CAD [TC], and ZENO ProFix [ZP]) and two chairside materials (Protemp 4 [PT], and Dentalon Plus [DP]) were used for the fabrication of the FDPs. Sixteen FDPs were fabricated from each material in an anatomical shape and stored in 0.9% NaCl solution at 37°C for 14 days. Thereafter, one half of the specimens from each group (n = 8) were additionally mechanically and thermally loaded (240,000 chewing cycles, 50 N, 5°/55°C, 2,100 thermal cycles). Fracture loads were measured and data analyzed using two- and one-way ANOVA, followed by Scheffé's post hoc test. ZP showed the highest mean fracture loads, regardless of the aging regime. Significantly lowest values were identified for DP and TC within the non-thermal loaded group, and for PT and CT within the thermal loaded group. No negative impact of aging regimes could be observed.

To evaluate the effect of immediate dentin sealing and optical powder removal method on the fracture resistance of CAD/CAM-fabricated ceramic endocrowns.Seventy-eight extracted premolars were endodontically treated. Standardized endocrown preparations were done in 60 teeth. Teeth were divided equally (n = 10) depending on the treatment of dentin (delayed sealing [DS] or immediate sealing [IS]), and the methods of optical powder removal (air-water spray washing [AW]; microabrasion [MA]; or aqueous suspension of pumice [PB], followed by air-water spray washing). After cementation, specimens were thermocycled (5,000 cycles, 5°C/50°C) and stored in distilled water for 1 week. Specimens were loaded in compression using a universal testing machine until failure. Failure load was recorded, and modes of failure were examined under a stereomicroscope. Micromorphological evaluation of different dentin treatments was done under SEM (n = 3). Results were analyzed using two-way ANOVA and Bonferroni post hoc multiple comparison tests (α = 0.05).Fracture resistance of all IS groups was significantly lower than DS groups, except for AW. There was no statistically significant difference between powder removal methods.Immediate dentin sealing does not improve the fracture resistance of endocrown restorations. Air-water spray washing is adequate to remove the optical powder after optical scanning impression taking.

In 55 patients, 25 endocrowns (test) and 40 shoulder crowns (control) were produced chairside in a private practice using the Cerec 3 (CAD/CAM) method and Vita Mark II feldspathic ceramic. The crowns were examined at baseline and after up to 12 years using modified USPHS criteria. The survival estimate was assessed by Kaplan-Meier analysis. The 12 years survival estimate of the shoulder crowns was 95% on molars and 94.7% on premolars. Endocrowns showed 90.5% survival on molars and 75% on premolars. Statistically, the differences between the survival estimates were not significant (P0.05). The longevity of Vita Mark II Cerec 3 shoulder crowns on molars and premolars, as well as of endocrowns on molars, proved to be--for private practice--a very acceptable result, while the premolar endocrowns tended to show a higher risk for failure.

Dental materials, especially in restorative dentistry, must not only be cost-effective, they must also meet many other requirements: biocompatibility, durability, excellent shade and light effects, abrasion resistance, hardness, mechanical strength under pressure, chemical resistance, surface density, ease of manufacture, and easy intraoral maintenance.

The primary goal of the present finite element (FE) analysis of a special removable prosthesis, the conical telescopic crown (CTC), was to validate established results based on a rigid model of the CTC and to analyze its characteristic features as a function of the essential material and geometric parameters. Furthermore, the effectiveness of a new element, the composite stop (CS), was investigated.The study used an axisymmetric FE model containing the inner and outer crown including resin or ceramic veneer, the CS, the cement layer between the interior crown and the tooth, and the upper part of the tooth itself.For a convergence angle (half-cone angle) α = 4 degrees and a moderate chewing force F = 150 N the loosening force decreased from - 50 N without to - 10 N with CS. Increasing α values yielded a decrease of the loosening force. Adherence between the inner (IC) and outer crown (OC) was achieved for all configurations (α = 2 degrees, 4 degrees, and 6 degrees), except for zirconium crowns with α = 6 degrees. In systems without CS, the maximum tensile stress in the veneer increased proportionally to F, but remained limited in those with CS.The angle a and the coefficient of static friction μ0 emerged as the decisive parameters of the CTC. The computed fitting/loosening behavior agreed well with results of a simple rigid-body model and experiments. The incorporation of a CS allows ceramic veneering of the outer crown.The optimal angle α of the CTC is ascribed to a number of customary material combinations for IC and OC. The CS limits the loosening forces of the CTC to values which guarantee non-traumatic removal of the prosthesis.

The aim of this article is to discuss the different types of monolithic ceramic crowns that can be placed on anterior teeth with existing shoulder preparations. Anterior crowns were indicated for the teeth 12 to 22 in the present case. The patient, a 65-year-old male, had received all-ceramic crowns 20 years earlier, which had started to develop cracks and palatal fractures over the last few years. The patient's teeth were prepared and four sets of crowns were fabricated using different monolithic ceramic materials: IPS e.max CAD, Cerec Blocs C In, VITABLOCS Real Life, and ENAMIC. Both shade characterization and crystallization firing were performed on the monolithic lithium disilicate glass ceramic crowns. The silicate ceramic crowns received glaze firing alone. The crowns made of hybrid ceramic (ENAMIC) were treated with a polymer sealant.

This study evaluated the clinical outcome of CAD/CAM zirconia-ceramic resin-bonded fixed dental prostheses (RBFDPs) with a cantilevered single-retainer design.Thirty anterior zirconia-ceramic RBFDPs fabricated with the Cerec CAD/CAM system were inserted using either a phosphate monomer containing resin (Panavia 21 TC; N = 16) or an adhesive bonding system with a phosphoric acid acrylate primer (Multilink-Automix with Metal/Zirconia primer; N = 14).During a mean observation time of 64.2 months, one debonding occurred in each group. Both RBFDPs could be rebonded successfully resulting in a five-year survival rate of 100%.Independent of the bonding system, cantilevered zirconia-ceramic RBFDPs showed promising results during the first five years. (ClinicalTrials.gov Identifier: NCT01411592).Single-retainer zirconia ceramic RBFDPs present an alternative treatment option offering good esthetics, a minimally invasive preparation, a high biocompatibility and can even be used to treat juvenile patients who do not yet come into consideration for implant placement. No significant influence of the bonding system used has been detected so far.

This case report demonstrates how two opposing teeth were restored with full crowns using Cerec software version 4.2 (pre-release version). In addition, an anterior tooth was provided with a veneer. The situation was scanned with the Cerec Omnicam. The new virtual articulator was used for the design to obtain correct dynamic contacts. The Cerec Omnicam can scan the entire situation prior to preparation without the help of an assistant, as no surface pretreatment is necessary. The locations of the occlusal contacts can be marked with articulating paper and are indicated on the virtual models. Selective deletion of individual areas allows the prepared teeth to be rescanned, considerably speeding up the workflow. A video demonstration is available of the acquisition and design procedure.

Intracoronal restorations have a variable risk of cusp fracture depending on the amount of tooth structure remaining. All-ceramic restorations with acusp-supporting design could be a long-lasting alternative. The aim of this study was to verify the clinical reliability of occlusal veneers. A total of 286 occlusal veneers made of Vita Mark II ceramic that were fabricated and inserted in 244 patients from 2003 to 2004 using the Cerec method with an optimized ceramic design were periodically re-assessed over the following years. Based on the fracture rate observed over 93 months of follow-up, the probability of survival was 99.3%, demonstrating the excellent practical suitability of the method. In light of this, it is worth reconsidering the question of treatment with intracoronal restorations versus occlusal veneers in the posterior region.

To examine the performance of CAD/CAM all-ceramic resin-bonded bridges (RBBs) fabricated from a glass ceramic material, and determine the influence of two different preparation designs on the fracture strength of these prostheses.Twenty human central incisors were used, placed into two groups. A clinical situation where a lateral incisor was missing was simulated. A minimal preparation design (palatal veneer preparation) and one that extended into the proximal area were applied in each group. The Cerec InEos and the Cerec 3D software were used to scan, design, and mill the restorations. A lithium disilicate glass ceramic material was used for the fabrication of the bridges (IPS e.max CAD). Twenty bridges were milled which were adhesively bonded on their abutments (Variolink II). A universal testing machine was used to evaluate the fracture strength and the mode of failure of the bridges.The mean fracture strength for the minimal design group was 774 N (+/- 341) and for the extended preparation group 814 N (+/- 474). No statistically significant difference was found between the two designs (p0.05). The mode of failure was fracture at the connector area between the pontic and the retainer wing.The fracture strength of the RBBs fabricated with IPS e.max CAD was in a clinically acceptable range. The two preparation designs did not have a significant influence on the fracture strength of the RBBs.

This study measured the bond strength of the self-adhesive resin cements and a bonded resin cement for crowns bonded to extracted teeth with preparations having a total taper greater than 30 degrees. A crown pull-off test was used with direction of pull along the path of insertion. The CAD/CAM system Cerec was used to create crowns with the pull-off loop as an integral part of the crown structure.One hundred extracted human molars were prepared for all-ceramic crowns with a 1.5-mm shoulder, greater than 30-degree axial wall convergence, a flat occlusal surface and 3 to 5 mm occlusal/ gingival height. All-ceramic crowns were cemented with five different self-adhesive cements (Rely X Unicem, Maxcem Elite, BisCem, SmartCem 2, and G-Cem) and one bonded resin cement (Multilink). Forfour cements (excluding GCem and Multilink) there were 2 groups, one with HF etching and one without ceramic surface treatment. The crowns were then subject to tensile stress until either the crown fractured or the crown was lifted off from the tooth.For several cements, the bond strength exceeded the tensile strength of the all-ceramic crown; thus, the crown fractured, leaving the cemented part of the crown on the tooth. The effect of ceramic surface etching was not statistically significant at p = 0.05; however, for each cement, the treated crowns showed a lower coefficient of variance (COV). For this study, the COV ranged from 24.9 % to 97.9 %. Loads ranged from 41.3 to 190.3 N.Some of the new self-etching resin cements can create bonds to non-retentive crown preparations that are stronger than the strength of a ceramic crown; however, these high bond strengths may not be able to be achieved consistently.

This practice-based study evaluates the initial clinical performance of conventionally luted metal-ceramic and zirconia molar crowns fabricated with a prolonged cooling period of the veneering porcelain. Forty-nine patients were treated (group A: high precious alloy + low fusing porcelain; group B: zirconia crowns). All zirconia crowns were veneered with a modified porcelain firing cycle including a 6-minute cooling period. Ninety-two restorations (74 vital abutments/18 nonvital abutments) were evaluated after a mean observation period of 18.2 +/- 4.6 months. No complete failures or loss of vitality were recorded in either group. Two events were recorded in group A (1 loss of retention/1 minor ceramic chipping2 mm2). The third event occurred in group B (minor ceramic chipping2 mm2). All ceramic defects could be polished intraorally. Statistical analysis revealed non-significant differences in success rates (p = 0.91) of metal-ceramic and zirconia crowns fabricated with a modified porcelain firing. The modified firing of the zirconia porcelain seems to decrease the risk for early ceramic chipping in the molar area, leading to a technical complication rate comparable to that of metal-ceramic crowns.

The aim of this prospective clinical study was to assess the long-term clinical survival rate and the technical and biological complication rates of zirconia-based posterior FDPs.Forty-five patients in need of one or more posterior FDPs received 57 three- to five-unit zirconia-based FDPs. The frameworks were fabricated by means of a prototype computer-aided manufacturing (CAM) system (direct ceramic machining, DCM), first processing zirconia in the white stage. The frameworks were veneered with a prototype veneering ceramic.The FDPs were adhesively placed. At baseline, 6 months, and 1,2, 3, 5, 8 and 10 years of function, the FDPs were examined for technical and/or biological complications. Furthermore, the periodontal health of the abutment teeth (test) and untreated control teeth was analyzed. Statistical analysis was performed applying descriptive statistics, Kaplan-Meier survival and multiple mixed effects regression tests.Twenty-one patients with 26 FDPs were examined at a mean observation time of 10.7 +/- 1.3 years. A total of 16 FDPs were lost to follow-up. Fifteen FDPs had to be replaced due to technical/biological complications; hence, the 10-year survival rate of the FDPs was 67%. Three framework fractures occurred, resulting in a 10-year survival rate for the zirconia frameworks of 91.5%. Chipping/fracture of the veneering ceramic was detected in 16 FDPs over 10 years (complication rate 32%). A significant correlation of the span of the FDPs and the incidence of chipping was observed: 4- and 5-unit FDPs had a 4.9 times higher probability for chipping than 3-unit FDPs. Marginal discrepancy/degradation was found in 90.7% of the FDPs over 10 years. At 11 of the FDPs (complication rate 27%), secondary caries occurred. No difference of the periodontal health was found around test and control teeth.The zirconia frameworks exhibited very good long-term stability. However, the zirconia-based FDPs frequently exhibited problems such as marginal deficiency or chipping of the veneering ceramic. Both problems may be associated with the prototype status of the system.

Despite the success in preventing oral diseases, the prevalence of tooth loss in the German population remains high and increases with age. Today, the advances in prosthetic dentistry allow necessary tooth replacement following preventive strategies-after considering benefits and risks. Modern treatment options improve the overall prognosis of the stomatognathic system and the quality of life of the affected patients significantly. Hereby, adverse iatrogenic effects can be minimized or even completely avoided by extending the traditional treatment spectrum, e.g., using adhesively fixed restorations and implant-supported restorations, and refraining from placing restorations that are unnecessary from the medical point of view. Generally, patients benefit greatly from prosthetic treatment and the achieved health gain is remarkably high. It encompasses not only the recovery of the impaired oral functions but also extends to the whole human organism, including nutrition, digestion, musculoskeletal system, as well as mental and social well-being.

When using dental duo-magnet systems, a mini-magnet remains in the jaw after removal of the prosthesis. In some cases, implant-borne magnets may be removed, whereas tooth-borne magnets are irreversibly fixed on a natural tooth root. The goal of this paper is to identify the impacts of the duration and orientation of exposure on these magnets in a 1.5 or 3 Tesla MRI.For this study, 30 SmCo and 60 NdFeB magnets were used. During the first experiment, they were exposed with free orientation for 64 minutes. During the second experiment, the magnets were fixed in position and exposed at 1.5 and 3 Tesla while aligned in a parallel or antiparallel direction.While the duration of exposure in MRI is irrelevant, the orientation is not. The coercive field strength of these NdFeB and SmCo alloys is not sufficient to reliably withstand demagnetization in a 1.5 or 3 T MRI when aligned in an antiparallel direction. At 1.5 T neodymium magnets were reduced to approx. 34 % and samarium magnets to approx. 92 % of their initial values. At 3 T all magnets were reversed.As a precaution, the worst-case scenario, i. e. an antiparallel orientation, should be assumed when using a duo-magnet system. If an MRI can be postponed, the general dentist should remove implant-borne magnets. If there is a vital indication, irreversible damage to the magnets is acceptable in consultation with the patient since the replacement costs are irrelevant given the underlying disease.

Results of immediately loaded implants are presented. 34 patients with 136 interforaminal MonoType implants (Straumann,Basel, Switzerland) were included in the study. The bar retention was manufactured fter the operation, inserted and covered with a hybrid prosthesis. 28 patients showed up for the follow-up study, the average time range was three years. Five implants were rated as failures, the cumulative six-year success rate being 94%. Interforaminal immediately loaded MonoType implants in edentulous patients showed very good results, comparable to similar studies with different systems.

Ceramics have been used in dentistry for many years. Especially during the last few years, the development of ceramic-related technology has steadily increased, and all-ceramic crowns are in the process of replacing traditional gold restorations on the market. Despite the relatively long experience with the material and technology, there are still only afew clinical studies on the long-term success rates. For this paper, three different ceramic systems (In-Ceram, Empress 2, and Cergo) were examined and results compared with the findings of the existing literature. Furthermore, the clinical follow-up examinations intended to determine the extent to which subgingival restoration margins influence the periodontium.

The present clinical study evaluates the clinical prognosis of Cerec3D endocrowns over an observation period of two years. Twenty Cerec endocrowns (VITABLOCS Mark II, Vita Zahnfabirk, Bad Säckingen, Germany) were placed with PanaviaTM F 2.0, a dual-curing bonding composite. The control examinations took place semi-annually and the restorations were evaluated based on modified US Public Health Service criteria (USPHS). The two-year survival rate of the Cerec endocrowns was 90%. Two out of 20 endocrowns were assessed as failure because of fractures. The first fracture was observed after 12 months and the second fracture after 18 months. No recurrent caries was diagnosed during the entire examination period. Slight percussion symptoms were found on three restorations in the first weeks after placement. The results of the present study show that good esthetic and functional results similar to those of other restoration types can be achieved with endocrowns and that CAD/CAM-fabricated crowns represent a very promising treatment alternative for endodontically treated molars.

Dental injury is one of the most anaesthesia-related complications. It can cause a patient's functional, esthetic, financial, and emotional annoyance. The incidence of dental injury is said to range from 1:6000 to 1:1000. The upper incisors are by far the most often injured teeth. Removable dentures should be taken out prior to anaesthesia. A tooth guard can be used as a prophylactic measure. However, with that tracheal intubation can be complicated because of the reduced view at the epiglottis and the vocal cords. If a dental injury occurred, the patient should be seen by a dentist as soon as possible to undergo appropriate treatment with no delay.

The reconstruction of the severe atrophy of the maxilla using dental implants requires extensive surgical treatments. Sinus lift procedure, ridge augmentation with free bone grafts or free vascularized bone transfers represent the common techniques. With regard to a higher life expectancy the number of patients suffering from limited chewing function based on atrophic bone conditions will increase. In addition to a higher number of failed implants in elderly people ask for other treatment strategies to regain proper oral function with limited surgical effort. This case report presents the failed treatment of maxilla, using disc implants and shows the new maxillary reconstruction using Brånemark-Zygoma implants combined with standard Nobel Replace implants in order to avoid extensive augmentation procedure.

Ceramic inlays and partial crowns have become scientifically recognized posterior restorations. Their clinical effectiveness depends on the development of durable dental ceramics and luting materials as well as an effective bonding system. Therefore, these factors were in the focus of interest in the past. In contrast, only little attention was given to preparation techniques. However, current studies show that special preparation rules should be followed to ensure best fitting CAD/CAM ceramic restorations and long-lasting clinical success. This paper describes preparation requirements by means of detailed three-dimensional schematic drawings and then deduces the clinical procedure for the preparation of ceramic inlays and partial crowns with standardized preparation instruments.

This case report presents the treatment sequence of a 56 years old patient after he developed periimplantitis at the implant in position of tooth 22. This implant was integrated in an overdenture reconstruction connected to a soldered screw retained gold bar. The entire 2-stage procedure of implant explantation, simultaneous bone augmentation and new implant placement is documented. The onlay-graft was performed by means of the Transfer-Ring-Control System (Meisinger). The existing gold bar could be resoldered and adapted to the new implant. Accordingly the overdenture was relined and the female retainer mounted. The treatment period covered almost one year.

Periapical surgery is required when periradicular pathosis associated with endodontically treated teeth cannot be resolved by nonsurgical root canal therapy (retreatment), or when retreatment was unsuccessful, not feasible or contraindicated. Endodontic failures can occur when irritants remain within the confines of the root canal, or when an extraradicular infection cannot be eradicated by orthograde root canal treatment. Foreign-body reponses towards filling materials, towards cholesterol crystals or radicular cysts might prevent complete periapical healing. Following enhanced microsurgical techniques in the last years the success rates of apical surgery have improved considerably. The aim of the current case report is to describe the therapeutical approach to a persistent periapical lesion and its histologic examination.

One of the main treatments in dental practice is the exchange of restorations due to secondary or residual caries. Thereby, only restorations indeed infected with secondary or residual caries should be renewed. The aim of the study was to check the validity of different criteria for the replacement of fillings. Three hundred seventeen replacements of dental restorations were evaluated retrospectively by using an examination form. Different clinical parameters were correlated with the finding of caries after removal of the old restoration. Clinical findings were differentiated between caries soft to probing, caries only stainable with caries detector and caries-free cavities. Sixty-seven percent of the cavities showed caries that could be probed, 16.1% were just stainable with caries detector and 17% were caries-free. In general, results of previous replacements of fillings were a valid criterion. Other indicators for caries-free cavities were properly placed fillings with a correctly reconstructed morphology, fillings without marginal defects, a low age of the filling and a positive impression of the patients' general hygiene. Indicators for cavities with secondary caries were marginal gaps, pain within the respective section of the jaw, a high number of filled surfaces and a bad impression of the general hygiene. Systematic diagnostic criteria should be adopted in decision making on replacement of fillings in order to avoid new restorations of caries-free cavities.

The range of bone regeneration materials suitable for maxillar bone augmentation has increased steadily in the past few years and there is now a wide variety of materials being used. In the present case report, we analyzed the state of bone regeneration after sinus floor augmentation using a nanocrystalline in-phase synthetic anorganic hydroxyapatite bone grafting material (Ostim). A 60-year-old female patient underwent maxillary sinus floor elevation and the cavity was filled with Ostim three years before. Actually, she presented herself with loosening of the dental implant at position 17, as a result of parafunction. At the time of the insertion of a second implant at position 17, bone samples were taken by using a trepan drilling device from the previously augmented area. These samples were analyzed histologically to determine the extent of bone remodeling around the deposits of Ostim. We found that the Ostim deposits were surrounded largely by woven bone and, in parts, by lamellar bone and had facilitated osteoconductive bone regeneration. The adjacent implant, at position 16, which beared a crown exposed to proper biting forces without parafunction, showed proper clinical and radiological characteristics of complete and firm integration into the area which was also filled with Ostim three years ago. We conclude that the use of the nanocrystalline hydroxyapatite Ostim with its stable volume properties appears to be suitable for maxillary sinus floor augmentation. Furthermore, we even found osteoconductive bone regeneration under Ostim near the site of the loosened implant.

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.

The subperiosteal dental implantation implant was orginally described in the 1940s. The inadequate long-term results of subperiosteal implants are in contrast to the excellent results documented for endosseus oral implants. Consequently, subperiosteal implants and other soft-tissue-anchored implants should not be used presently. The present report documented twelve patient cases with complications after treatment with subperiosteal implants. Typical complications of SI are implant exposure, inflammation, infection, fistula formation and implant mobility. After removing the SI severe atrophic bone was seen. The placement of osseointegrated oral implants was mostly not possible without autogenous bone grafting. The present report is in conclusion with other studies, that a regular control of patients with subperiosteal implants is necessary. Subperiosteal implants should definitely be removed, if continuous periods of complication occur. The complete oral rehabilitation requires further surgical treatment in the field of preprosthetic surgery.

Objective: To assess and compare the prevalence, type and frequency of complications during Herbst treatment with reduced (canine to 2nd premolars) and total (canine to molars) mandibular cast splints. Subjects and Methods: Fifty consecutive Herbst patients treated with reduced mandibular splints (RMS) were compared to 182 consecutively treated Herbst patients with total mandibular splints (TMS). The prevalence, type and frequency of complications were analyzed. Results: The prevalence of patients with complications did not differ significantly between the groups, and amounted to 58% in the RMS- and 60% in the TMS-group. The most frequent type of complication in both groups was maxillary splint loosening, making up 56.3% of all complications in the RMS- and 66.9% in the TMS-group. The second most frequent complication was mandibular splint loosening, which amounted to 32.5% of the complications in the RMS- and 26.8% in the TMS-group. We observed telescope breakage twice as often (8.8%) in the RMS- as in the TMS-group (4.3%). Conclusions: Loosening of the maxillary splints is the main complication during Herbst treatment with RMS and TMS. A reduction in mandibular splint length does not increase the prevalence of complications, but it does reduce expenses, and can thus be recommended for further use.

Clinical aspects of a simple treatment concept with fixed prostheses in the edentulous jaw are described. Fixed implant-supported reconstructions in the edentulous jaw require multiple implants, are technically complex, aesthetically demanding and metal-ceramic solutions are expensive. Specific surgical techniques to enhance the hard and soft tissue conditions become often necessary. Thus the bar-supported overdenture may be preferred, because problems with aesthetics and alveolar ridge deficiencies can be solved more easily and the number of implants is reduced. Both, the "All-on-Four" technique and the "Procera implant bridge" are simple type of fixed prostheses, comparable to overdentures or complete dentures with regard to design and technology. They present a cost-effective alternative, with predictable aesthetics and optimum passive fit.

It was the aim of this prospective clinical splitmouth investigation to evaluate the survival rate and long-term behavior of all-ceramic partial coverage restorations (PCR) on molars. Pressed ceramic (IPS e.max Press) and CAD/CAM made (ProCAD) PCR were compared. 80 vital molars of 25 patients were restored with all-ceramic PCR (40 IPS e.max Press* and 40 ProCAD*). All PCR were adhesively luted with a light-polymerizing composite (Syntac*/Tetric*) (*Ivoclar-Vivadent AG, Schaan, Liechtenstein). The ProCAD PCR were produced with Cerec 3 and Cerec Inlab CAD/CAM system (Sirona Dental Systems, Bensheim, Germany). IPS e.max Press PCR were heat-pressed following the lost-wax IPS-Empress method. Clinical recall was arranged in average 8, 14, 20 and 28 months after cementation of the restoration. PCR were classified by USPHS criteria. The prospective survival rate of ProCAD PCR was 97% and 100% for IPS e.max Press PCR after an observation period of 24 months. After fracture, one ProCAD restoration had to be replaced after nine months. The clinical accuracy of the marginal fit of ProCAD PCR and IPS e.max Press PCR was recorded "Alfa". Limitations were recognized with respect to the color matching of both types of PCR ("Bravo").Within the limits of the present clinical results, the tested all-ceramic materials IPS e.max Press und ProCAD seem to be indicated for partial coverage restorations on molars.

The new Swiss implant system SPI became available three years ago and is used in combination with fixed and removable prosthetic reconstructions. In a pilot study the clinical procedures were evaluated and data of prosthetic complications of maintenance service were collected. 25 patients participated in the study with a total of 79 SPI implants during the time period from 2003-2004. 37 implants were located in the maxilla and 42 implants in the mandible. Two implants failed during the healing period, but no loaded implant was lost. Thus, the survival rate was 97.5% (77/79). 44 implants supported a fixed prosthesis, including nine single crowns and 33 implants were used in combination with removable partial denture. Four implants were used with ball anchor retention, 29 with bar support. The ELEMENT implant with the low implant shoulder allows very good esthetics. Prosthetic complications and maintenance service during the first year of function was comparable with other implant systems. Since the design of the abutment screws, healing caps and screwdriver was changed, the system has become easier in its application.

The planning of dental implant position and its transfer to the operation site can be considered as one of the most important factors for the long-term success of implant-supported prosthetic and epithetic restorations. This study compares computer-assisted fabricated surgical templates as the static method with intro-operative image guided navigation as the dynamic method for transfer of three-dimensional pre-operative planning. For the static method, the systems Med3D, coDiagnostix/ gonyX, and SimPlant were used. For the dynamic method, the systems RoboDent und VectorVision2 were applied. A total of 746 implants were inserted between August 1999 and December 2005 in 206 patients. The static approach was used most frequently, accounting for 611 fixtures in 168 patients. The failure ratios within the first 6 months were 1.31% in the statically controlled insertion group compared to 2.96% in the dynamically controlled insertion group. Complications related to an incorrect position of the implants have not been observed so far in either group. All computer-assisted methods included in this study were successfully applied in a clinical setting after a certain start-up period. The indications for application of computer-assisted methods in implantology are currently given in difficult anatomical situations. Due to uncomplicated handling and low resource demands, the static template technique can be recommended as the method of choice for the majority of all cases falling into this category.

A retrospective analysis of sinusfloor elevation and implantation should evaluate in a sense of quality control the clinical results and complications during or after sinusfloor elevation. In our institution we performed 98 sinusfloor elevations in 80 patients (44 women, 36 men) between August 9, 1995 and November 18, 2002. In those elevated sinuses, 201 implants were inserted till October 16, 2003. Dates were sampled from the patient medical histories. Sinusfloor elevation and implantation in posterior maxillary bone have a good prognosis. Nevertheless implant survival depended on the chosen implant system (Kaplan-Meier-analysis). Implant survival was 98% for Straumann implants and 80% for Frialit-II implants after two years. A significant correlation between Frialit-II implants and Straumann implants (p=0.0119) was identifiable. There was no difference in healing between different augmentation materials (autogenous bone, Ceros 82, Algipore), but case numbers were too small for a relevant validity. In one-stage procedures implant loss was 8%, in two-stage procedures it was 18%. Implant losses in smokers were generally higher than in non-smokers. The period of consolidation of the augmentation's material introduced in two-stage procedures was about 10.3 months, healing time of implants 9.2 months. In one-stage procedures healing time of implants was about 7.7 months. Membrane perforations during surgery occurred in 11% and were not related to the development of postoperative sinusitis as described in literature.

VITA In-Ceram Classic is a system to fabricate all-ceramic crowns and fixed partial dentures (FPDs) with a glass-infiltrated aluminium oxide core material. This systematic review gives an overview of the clinical performance of the In-Ceram Classic types Alumina, Spinell and Zirconia. Based on a systematic literature research, an evidence-based selection and assessment of clinical studies of In-Ceram Classic ceramics was carried out. A total of 294 publications were found, 21 of which conformed to the inclusion criteria. Only few meaningful studies of In-Ceram Alumina FPDs and In-Ceram Zirconia crowns and FPDs were found. The Five-year survival rate of In-Ceram Alumina crowns and In-Ceram Spinell crowns ranging from 91.7% to 100% is similar to the survival rate of conventional metal-ceramic crowns. The Five-year survival rate of single-retainer In-Ceram Alumina resin-bonded fixed partial dentures (RBFPDs) was 92.3%, and thus higher than that of two-retainer RBFPDs. In-Ceram Classic Alumina can be recommended for anterior and posterior crowns as well as for anterior single-retainer RBFPDs. In-Ceram Classic Spinell can be recommended for anterior crowns. Further studies have to be initiated in order to evaluate in detail the clinical performance of VITA In-Ceram Classic.

There are no long-term clinical studies concerning the treatment outcome of CAD/CAM generated porcelain laminate veneers. The objective of this study was to conduct a longitudinal evaluation of CAD/CAM fabricated porcelain laminate veneers. A single practitioner placed 715 CAD/CAM generated porcelain laminate veneers produced chairside with the Cerec system on 307 patients between December 1989 and December 1997. 260 patients with 617 veneers were available for recall examination. Forty-seven patients with 98 veneers (13.7%) were unable to be located or return for recall examination. Fourteen restorations had been lost. The Kaplan-Meier survival rate was 94% after up to 9 years (95% confidence interval: 90.7 to 97.8%). Of the surviving restorations, 98% were classified as clinically acceptable after 9 years. 97.3% of the teeth examined tested vital, 96.2% of the veneers were asymptomatic since their production, 98.8% of the veneers were considered successful by the patient. CAD/CAM veneers fabricated with the Cerec System achieved comparable long-term clinical results to those reported for laboratory processed porcelain laminate veneers. The high survival rate and favorable clinical results would support the use of CAD/CAM porcelain laminate veneers in clinical situations similar to those for laboratory processed porcelain veneers. CAD/CAM generated porcelain laminate veneers may provide equally good clinical results and longevity as conventional laboratory-processed porcelain laminate veneers.

Ziel dieser prospektiven Studie war es zu ermitteln, ob die Pravalenz parodontopathogener Markerkeime und zwei Polymorphismen im Interleukin-1-Gencluster auf Chromosom 2, die eine enge Assoziation mit dem Auftreten einer Parodontitis zeigen, den Erfolg der Sofortimplantation direkt nach Zahnextraktion im parodontal geschadigten Gebiss beeinflussen. Bei 59 Patienten (22 Manner und 37 Frauen im Alter zwischen 20 und 81 Jahren, Altersmedian 55 Jahre) mit chronischer Parodontitis erfolgten vor Zahnentfernung zwei Probeentnahmen zur molekulargenetischen Diagnostik funf parodontaler Keime (Haemophilus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia sensu stricto, Treponema denticola) und zur Identifizierung des Interleukin-1-Genotyps. Direkt post extractionem wurden 95 Implantate (26 Ankylos®- und 69 Camlog®-Root-Line-Implantate) inseriert, wovon 78 prothetisch sofort versorgt wurden. Unter den Probanden befanden sich 18 Raucher. Der Beobachtungszeitraum betrug 1 Jahr post operationem. Es kam zu einem Verlust von 4 Implantaten bei 4 Patienten mit Tabakkonsum. Bei diesen Probanden konnte kein IL-1-Polymorphismus nachgewiesen werden, Markerkeime fanden sich nur bei einem Patienten. Das mikrobiologische Spektrum der Raucher unterschied sich nicht wesentlich von dem der Gesamtpatientenanzahl. Von den 59 Patienten wiesen 23 (39%) einen positiven IL-1-Genotyp auf. Die Implantatverlustrate von 4% bei Sofortimplantation 1 Jahr nach der Operation ist gegenuber der der Spatimplantation nicht wesentlich erhoht. Es konnte ein Zusammenhang zwischen Tabakkonsum und Implantatverlust hergestellt werden, Auswirkungen auf das mikrobiologische Keimspektrum und den IL-1-Polymorphismus ergaben sich nicht. Daraus lasst sich folgern, dass die Sofortimplantation direkt nach Extraktion auch bei Bestehen einer Parodontitis eine erfolgreiche Alternative zur konventionellen Spatimplantation darstellt.

The precondition for introducing medical products, e.g. new filling materials, in the European Union is their safety, not their clinical reliability. The latter arises from longitudinal studies and is assessed on the basis of available standards or, if not existant, on formulated quality guidelines. In the case of the specific products Ariston Liner and Ariston pHc (Vivadent, Schaan, FL), designed as an amalgam substitute, the material combination did not correspond to the Swiss standard 2 of restorative dentistry. Although after a short-term application testing on caries free premolars the pulp and dentin were free from inflammation and bacteria, the material combination clinically failed within the 18 months control period with a cumulative failure rate of 16.1% due to marginal caries. After six months of function the subjectively assessed sensitivity tended to increase. Gap formations and porous zones were detected in the composite-tooth-interface in vitro as well as in vivo. Neither the lining, designed to ensure the passage of cations and anions out of the filling material, nor the concept of an adequate caries protective effect proved successful. Marginal caries and hypersensitivity of teeth were the main reasons for the replacement of this amalgam substitute. The specific material combination was withdrawn from the market. As long as laboratory methods cannot substitute clinical evaluations, the introduction of new materials or systems into the market should be supported by short-term clinical studies and the further quality assessment should result from intermediate to long-term longitudinal studies. In this respect guidelines are valuable, such as the Swiss guidelines concerning materials as amalgam substitute.

The following study reviews patients from the Department of Oral Surgery and Stomatology at the University of Berne undergoing implant therapy. Between 2000 and 2002, 737 patients received 1176 ITI screw-type implants. At least 70% of these patients were 50 years or older. The main reason for tooth loss in this group was often periodontitis, followed by carious, periapical infection and root fractures. Only 15% of the patients were younger than 30 years. They had lost their teeth mainly due to trauma or agenesis of teeth. This study reports a trend towards treatment of partially edentulous patients (90%), with single tooth gaps (50%) being the most frequent indication for implant therapy. The analysis also demonstrated the importance of augmentation procedures prior to implant placement. Almost 40% of the implant cases required either ridge augmentation or sinus lift procedures. The GBR technique was frequently utilized in the anterior maxilla, especially with bone defects resulting from dental trauma. Data also showed that with these augmentation procedures more implants were inserted in the maxilla (53%) than in the mandible. During the healing or early loading phase only six implants out of 1176 were lost, resulting in an early failure rate of 0.51%. Our study has demonstrated that a high level of implant success can be achieved with the ITI system when using a strict selection criteria and stringent operating protocols.

The objective of this prospective clinical study was to calculate the survival rate of IPS-Empress2 crowns and fixed partial dentures (FPD) over a three-year period. In 43 patients 27 IPS-Empress2 crowns and 31 fixed partial dentures were adhesively luted. Crowns were placed on premolars and molars and FPDs were inserted in the anterior and premolar area. Abutments were prepared with a circular 1.2 mm wide shoulder. The clinical follow-up examination took place after 6, 12, 24, 36 and 48 months. After a mean of 38 months, the survival rate (Kaplan-Meier) of all-ceramic crowns was 100% and of the three unit FDP 72.4%. There were a total of six complete failures which occurred only with the three-unit IPS-Empress2 FPDs. Three FPDs exhibited fractures of the framework for which the manufacturer's instructions of connector-dimension was not satisfied, and one FPD exhibited an irreparable incomplete veneer fracture. Further two FPDs showed biological failures. The accuracy of fit and esthetics were clinically satisfactory. The three-year results showed the IPS-Empress2-ceramic as an adequate all-ceramic material for single crowns. The use for FPD needs further critical consideration.

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.

In a dental practice, 2328 ceramic inlays were placed in 794 patients. The restorations were manufactured chairside using Cerec technology and adhesively inserted at the same appointment. The clinical performance of the restorations was evaluated with the Kaplan-Meier analysis. The probability of survival was 95.5% after 9 years; 35 Cerec restorations were judged as failures. The prognosis for success was not significantly influenced by restoration size, tooth vitality, treatment of caries profunda (CP), type of tooth treated, or whether the restoration was located in the maxilla or mandible. The most common type of failure was the extraction of a tooth. In a clinical follow-up light-microscopic examination of 44 randomly selected restorations, an average composite joint width of 236.3 microns was found. 45.1% of the restorations exhibited a perfect margin, and 47.4% of the investigated joint sections showed underfilled margins.

The use of dental implants is an established procedure for the treatment of partially edentulous patients. However, there is only little knowledge about the prosthetic outcome of implant-supported restorations. The purpose of this prospective long-term study was to evaluate success rates of implant-supported restorations in partially edentulous patients three years after loading. The study group consisted of 76 patients (47 females, 29 males) with 214 3i-implants (machined surface). 64 implants were used to support single crowns, 81 implants for 81 splinted crowns (36 units), 17 implants for seven bridges and 61 implants for 23 cantilevered bridges. For prosthesis construction, UCLA-Abutments were used. Screw connection was achieved by gold-alloy-coated square head screws and titanium hexagon head screws. Clinical follow-up visits were performed at the time of prosthesis insertion, three months, six months, one year, two years and three years after insertion of the prosthesis. The evaluation of the superstructures was performed according to the success criteria defined by Walton (1998). The success rate for the prosthetic reconstructions was estimated at 84.9% 36 months after loading. The success rate was 88.6% for fixed partial dentures, 86.4% for single crowns and 76% for cantilevered bridges. Technical problems included screw loosening, screw fractures, framework fractures, veneering material failures and failures because of implant loss and following remake or modification of the superstructures. Since mainly technical complications such as screw loosening and screw fractures were causing problems, the connection between implant and superstructure should be improved.

The use of osseointegrated implants is an accepted procedure for the treatment of complete or partially edentulous jaws. The purpose of this prospective long-term study was to evaluate the survival and success rates of endosseous dental implants (machined surface) in partially edentulous patients. A total of 76 patients (47 females, 29 males) with 214 implants (68 maxillary, 146 mandibulary) were evaluated. Their mean age was 45, ranging from 18 to 76 years. The implant length varied between 7 and 15 mm, the diameter between 3.4 and 6 mm. Nine implants were lost before abutment connection. Follow-up visits were scheduled at 3 and 6 months, 1 year, 2 and 3 years after insertion of the prostheses. Radiographic examination included intraoral periapical films to evaluate the horizontal and vertical bone loss. During the follow-up period, 18 implants in 10 patients were classified as failures. Fifteen implants were lost, and three implants were considered failures because of vertical bone loss greater than 0.2 mm per year after the first year of functional loading. The marginal bone loss averaged 2.1 mm in the maxillae and mandibles. According to the Kaplan-Meier estimator the probable implant survival and success is at 93% and 88% respectively after 63 months. Long implants (10 mm) have a significantly better chance of survival than shorter implants (or = 10 mm). The results of this prospective study indicate that 3i endosseous dental implants provide an average foundation for implant-supported restorations.

As an effort to reduce the treatment time in dental implantology, immediate loading has received increasing attention during the past years. The success of early and immediate loading of implants in the interforaminal region is well documented in the dental literature. However, early loading of implants still bears an increased risk. Therefore, strict patient selection is needed. In this case report the rehabilitation of a patient with an immediately loaded implant-supported cantilever fixed partial denture in the mandible is presented. The occurrence of complications few weeks after loading lead to the explantation of two of the five implants. As a consequence, the patient was restored with an implant-retained overdenture.