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Locator® and ball attachments are well-established systems to attach overdentures to two inter-foraminal implants. This study aimed to evaluate differences between the two systems regarding prosthetic maintenance and patients’ oral-health-related quality of life (OHRQoL). Dental records of patients with a mandibular implant-retained overdenture were retrospectively analyzed. Prosthetic maintenance measures involving the denture suprastructure and attachment matrix and patrix were analyzed. Furthermore, the Oral Health Impact Profile-G14 (OHIP-G14) was used to evaluate OHRQoL. Results were analyzed by means of Kaplan–Meier analysis and Student’s t- and log-rank tests. The records of 122 patients were evaluated. Kaplan–Meier survival analysis revealed a significant difference between ball attachments (Group B, n patients = 47) and Locator® attachments (Group L, n patients = 75) regarding the occurrence of denture fractures (p &lt, 0.001) and events affecting the matrix (p = 0.028) and patrix (p = 0.030). Group L had a significantly lower total OHIP-G14 score than Group B (p = 0.002). The most common maintenance events were matrix-related and denture relining for both attachment systems. Group B required more maintenance measures than Group L. Moreover, patients in Group L had better OHRQoL than patients in Group B.

Background Dental implantology has become an established option for treating tooth loss over the recent decades. Before inserting an implant in a clinical situation, theoretical and practical training is recommended. Different methods are available to give assistance in determining the correctly planned implant position. In this study, two different guiding methods were assessed considering their accuracy for implant insertion in a group of dentists. Methods After three-dimensional planning of the implant positions, two surgical templates were manufactured as follows: in region 34 a stereolithographic template was used to perform a full-guided implant insertion, in region 44 a CAD/CAM milled template was used to determine the implant position and subsequently, perform a free-hand insertion. In total, 86 implants were placed in mandibular models by 43 dentists participating in a postgraduate curriculum. The differences between planned and achieved implant positions were measured and statistically analyzed. Results The implants inserted fully-guided showed a lower deviation of the three-dimensional angulation (2.266 ± 1.443 degrees vs. 7.954 ± 4.372 degrees) and the cumulated mismatch of the implant position (0.547 ± 0.237 mm vs. 1.160 ± 0.427 mm) compared to the free-handed mode. For the angulation and the mismatch at the implant base the differences were statistically significant (p Conclusions Within the limits of the study it can be summarized that the full-guided implant insertion leads to a higher transfer accuracy compared to the free-hand method in a cohort of dentist inexperienced in dental implantology. However, the clinical effect has to be discussed as the study was performed using artificial mandibles and ideal conditions.

In the current literature, cone beam computed tomography (CBCT) seems to be more accurate in detecting apical lesions (AL) than two-dimensional radiographs. Cortical bone thickness might have an influence on AL visibility. Therefore, the purpose of the study was to directly compare the diagnostic accuracy of panoramic radiography (PANO) and CBCT in detecting AL in the upper jaw and determine the influence of cortical bone thickness on AL visibility. Anonymised digital images of 351 patients who received a CBCT image and a panoramic radiograph within 90 days were examined for AL in the upper jaw. The analysis was conducted by a trained examiner and reviewed by an expert in dental radiology. Further, the dimensions of AL and cortical bone thickness in the region affected by AL were measured to determine their influence on visibility. Statistical analysis was carried out by means of statistical software (IBM SPSS 25; Armonk, NY, USA). The mean age of the patients was 58.9 years with an almost equal gender distribution. A total of 2223 teeth in the upper jaw were included in the final analysis. CBCT detected AL on 144 teeth (6.5%), of which only 23 were also visible on a PANO. The difference between both methods was significant (p

Background Telescopic prostheses are an evidence-based treatment modality, and conical zirconia crowns and electro-formed gold copings have been used for dentures supported by teeth and/or implants. Purpose We aimed to evaluate the survival rates of zirconia-based tooth/implant restorations. Materials and methods A total of 126 telescopic overdentures, all retained by conical zirconia crowns and electro-formed gold copings, were retrospectively evaluated and failures analyzed for abutment configurations. Survival rates and modifying factors were evaluated by Kaplan-Meier analysis, log-rank testing, and Cox regression analysis. Results We evaluated observation periods of up to 11.5 years (mean: 45.25 ± 25.11 months). Five-year prosthesis survival was 96.9 ± 2.2% (95% CI: 92.6-100). Six dentures had been lost, and these failures were significantly associated with specific abutment configurations. Conclusions Within the limitations of this retrospective study, the concept of conical zirconia telescoping into electro-formed gold provides a viable alternative to other telescopic designs used for removable dental prostheses. The concept is well suited especially for tooth/implant-supported prosthetic rehabilitation.

Purpose The aim of the present randomized controlled study was to compare prefabricated all-ceramic, anatomically shaped healing abutments followed by all-ceramic abutments and all-ceramic crowns and prefabricated standard-shaped (round-diameter) titanium healing abutments followed by final titanium abutments restored with porcelain-fused-to-metal (PFM) implant crowns in the premolar and molar regions. Materials and methods Forty-two patients received single implants restored either by all-ceramic restorations (test group, healing abutment, final abutment, and crown all made of zirconia) or conventional titanium-based restorations. Immediately after prosthetic incorporation and after 12 months of loading, implant survival, technical complications, bone loss, sulcus fluid flow rate (SFFR) as well as plaque index (PI) and implant stability (Periotest) were analyzed clinically and radiologically. Results After 12 months of loading, an implant and prosthetic survival rate of 100% was observed. Minor prosthetic complications such as chipping of ceramic veneering occurred in both groups. No statistical significant differences were observed between both groups with only a minimum of bone loss, SFFR, and PI. Conclusion All-ceramic implant prostheses including a prefabricated anatomically shaped healing abutment achieved comparable results to titanium-based restorations in the posterior region. However, observational results indicate a benefit as shaping the peri-implant soft-tissue with successive provisional devices and subsequent compression of the soft tissue can be avoided.

Objectives: The aim of this study was compare two CAD/CAM zirconia abutments (1-piece abutment versus 2-pieces adhesively bonded abutment) for contamination, traces of processing and microscopic gaps. Material and methods: Three groups consisting of five identical abutments were cleaning with a steam jet and ethanol and then scrutinized by a scanning electron microscope (LEO 1530 VP; Oberkochen, Germany). The first group (1) contained individual CAD/CAM abutments (Atlantis™; Dentsply Implants, Mölndal, Sweden); the second group (2) contained adhesive bases before they were connected to their copings (Astra Tech Cast Design 4.5; Dentsply Implants) while the third group (3) contained the same adhesive bases but with a zirconia coping attached (Ceramill ZI; Amann Girrbach, Pforzheim, Germany). Results: All abutments in groups 1 and 3 and 4 out of 5 abutments in group 2 were found to be contaminated. Traces of processing were found only on the abutments in group 3. No microscopic gaps were present in groups 1 and 2. All 2-piece abutments in group 3 exhibited extensive bonding gaps that were unfilled, measuring 213 to >3,000 μm horizontally and 42 to 101 μm vertically. Conclusions/Clinical relevance: Both the instances of contamination and the microscopic gaps of the 2-piece abutments could cause damage to the hard and soft tissues around the implant. This topic would merit further investigation.

Implant-supported overdentures are an established dental treatment mode. The aim of this prospective study was and interindividual comparison of patient satisfaction with restorations retained by a prefabricated and thus inexpensive attachment system (Locator®) or with a technologically complex and thus expensive attachment system (ceramic/electroplated double crowns) with similar retentive performance. Twelve patients received a Locator and a double-crown prosthesis in a crossover study for test periods of 3 months each. The main target parameter was the patient’s final decision in favor of one of the two prosthesis types. After completing both test phases, seven patients opted for the Locator prosthesis and five patients opted for the double-crown prosthesis. Given the predominant lack of statistically significant differences, the two types of prostheses can be described as equivalent. A recommendation in favor of the Locator prosthesis can be motivated by its lower cost. The results of the study show that the more cost-effective variant was comparable to the more expensive double-crown prosthesis under the conditions prevailing in the study. Depending on the indication, this may influence the decision-making process in daily clinical practice and support the clinician’s patient information and consultation efforts.

Purpose The aim of this in vitro study was to evaluate the accuracy of template-guided implantation planned with implant-planning software (Implant Studio), comparing computer-aided design/computer-assisted manufacture (CAD/CAM)-based measurements with measurements via cone beam computed tomography (CBCT). Materials and methods Thirty template-guided implantations were planned and performed on acrylic-resin models. The implant positions were detected with an intraoral scanner, evaluated with CAD quality-control software, and compared with the planned positions in the test group. Preliminary deviations were measured via CBCT in the control group of the first 10 samples and compared with the first 10 samples of the test group. Results When directly compared, measurements obtained using CBCT (control group) showed a trend toward greater deviations. In the CAD/CAM-based evaluation of the 30 samples, the mean ± SD deviation of the insertion axis from the planned implant axis was 2.011 ± 0.855 degrees. The mean deviations of the implant shoulders in the horizontal direction and at the implant apices were 0.725 ± 0.142 mm and 0.990 ± 0.244 mm, respectively. In the vertical direction, the mean deviation was 0.541 ± 0.129 mm. Conclusion CAD/CAM-based measurements are more accurate than CBCT measurements. Therefore, this radiation-free measurement method is a viable diagnostic alternative. Implant planning with planning software and subsequent placement using surgical templates appears to be a reliable and precise therapeutic option in vitro. However, these findings will still have to be supported by in vivo studies.

Statement of problem Different luting materials are available for the cementation of fixed dental prostheses. Postcementation hypersensitivity is an occasional complication in the definitive delivery. How the choice of luting agent affects long-term postcementation sensitivity is unknown. Purpose The purpose of this prospective, randomized, controlled, split-mouth clinical trial was to compare the hypersensitivity of 2 cementation methods for metal-ceramic crowns. The primary endpoint was the evaluation of differences in hypersensitivity between the study groups over a study period of 5 years. Material and methods The study investigated 20 participants with 40 metal-ceramic crowns cemented with either zinc phosphate cement or a self-adhesive resin cement, each in nonantagonistic contralateral quadrants (observation period of 5 years). The data regarding postcementation hypersensitivity included continuous patient-related outcome variables assessed using a visual analog scale (sign test; primary endpoint, level of significance α/3=.0167; secondary endpoint, level of significance, α=.05) and categorical variables represented by yes/no replies (absolute and relative frequencies). The sensitivity of teeth was controlled in relation to mastication, air streams, and hot and cold temperatures. Results The observation period was 5 years, with a dropout rate of 12.5% in the last 2 years. The results indicated no significant differences between the cement groups for patient- and clinical-related outcomes at any of the observed time points. Conclusions As no differences were found between the 2 different cementation modes with respect to developing hypersensitivity after 5 years, the choice of a luting agent remains an individual practitioner decision.

Tooth colour determination is an essential component in the preservative and prosthetic workflow during production of tooth-coloured restorations. The aim of the study was to compare the clinical suitability of conventional, visual tooth colour determination and digital methods. Tooth colour of vital, natural central incisors among a total of 107 subjects was determined visually by a dentist (VD) and dental technician (VDT) using VITA Toothguide 3D-MASTER®, digitally by the spectrophotometer VITA Easyshade Advance 4.0 (reference instrument) and Trios®Color intra-oral scanner (test subject). Reliability was examined by repeating the digital measurements of 20 teeth three times. The analysis was based on the recorded 3D-MASTER values and L*a*b/L*C*h parameters. The measuring accuracy was 43.9% with the Trios®Color scanner, 35.5% for VD and 34.6% for VDT. In 25.5% of cases, the scanner’s results corresponded with VD and in 33.6% with VDT. The visual methods corresponded with 45.8%. All mean values of the recorded colour differences fell within the clinically acceptable range of ΔE ≤ 6.8. The intra-oral scanner attained repeatability of 78.3% and the VITA Easyshade system of 76.6%. The Trios®Color intra-oral scanner appears to be a good alternative to the current standard of visual tooth colour determination. The new module attains better results than the visual method and is comparable to the reference instrument. Dentistry becomes increasingly digitalized and tooth colour determination devices have generally to be improved. Therefore, the investigation of a new digital device is important for future developments.

Previous studies have often discussed occlusal concepts for complete dentures without formulating a recommendation. Various options are available, the most common ones being canine-guided occlusion (CGO) and bilateral balanced occlusion (BBO). We designed a prospective randomized study to compare these two schemes with the goal of formulating a recommendation. Forty patients could be evaluated. In a crossover design, they were randomized to a CGO>BBO group and a BBO>CGO group, each starting out by wearing their dentures with the first occlusal scheme for 3 months, followed by a first investigator- and patient-centered assessment. Then, each patient was transitioned to the other occlusal scheme by replacing the denture setup in the dental laboratory, followed by another 3 months of intraoral use and a second assessment. Wilcoxon–Mann–Whitney and marginal homogeneity tests were used for statistical analysis. All statistically significant differences favored the CGO concept. Based on patient ratings, the CGO>BBO group preferred its esthetics (p = 0.02) and the BBO>CGO group its mandibular retention (p = 0.05), phonetics (p = 0.03), and masticatory function (p = 0.01). Based on investigator assessments, maxillary denture retention was found to significantly improve among the BBO>CGO patients after transition to CGO (p = 0.01). Within the limitations of this study, canine guidance can be recommended as a comfortable alternative to bilateral balanced occlusion for complete dentures. This recommendation can reduce the time requirements for the fabrication of complete dentures in dental laboratories.

PURPOSE. All-ceramic restorations required extensive tooth preparation. The purpose of this in vitro study was to investigate a minimally invasive preparation and thickness of monolithic zirconia crowns, which would provide sufficient mechanical endurance and strength. MATERIALS AND METHODS. Crowns with thickness of 0.2 mm (group 0.2, n=32) or of 0.5 mm (group 0.5, n=32) were milled from zirconia and fixed with resin-based adhesives (groups 0.2A, 0.5A) or zinc phosphate cements (groups 0.2C, 0.5C). Half of the samples in each subgroup (n=8) underwent thermal cycling and mechanical loading (TCML)(TC: 5 degrees C and 55 degrees C, 2x3,000 cycles, 2 min/cycle; ML: 50 N, 1.2x10(6) cycles), while the other samples were stored in water (37 degrees C/24 h). Survival rates were compared (Kaplan-Maier). The specimens surviving TCML were loaded to fracture and the maximal fracture force was determined (ANOVA; Bonferroni; alpha=.05). The fracture mode was analyzed. RESULTS. In both 0.5 groups, all crowns survived TCML, and the comparison of fracture strength among crowns with and without TCML showed no significant difference (P=.628). Four crowns in group 0.2A and all of the crowns in group 0.2C failed during TCML. The fracture strength after 24 hours of the cemented 0.2 mm-thick crowns was significantly lower than that of adhesive bonded crowns. All cemented crowns provided fracture in the crown, while about 80% of the adhesively bonded crowns fractured through crown and die. CONCLUSION. 0.5 mm thick monolithic crowns possessed sufficient strength to endure physiologic performance, regardless of the type of cementation. Fracture strength of the 0.2 mm cemented crowns was too low for clinical application.

Purpose The aim of this study was to investigate the effects of tightening torque, screw head angle, and thread number on the preload force of abutment screws. Materials and methods The test specimens consisted of three self-manufactured components (ie, a thread sleeve serving as an implant analog, an abutment analog, and an abutment screw). The abutment screws were fabricated with metric M1.6 external threads. The thread number varied between one and seven threads. The screw head angles were produced in eight varying angles (30 to 180 degrees). A sensor unit simultaneously measured the preload force of the screw and the torsion moment inside the screw shank. The tightening of the screw with the torque wrench was performed in five steps (15 to 35 Ncm). The torque wrench was calibrated before each step. Results Only the tightening torque and screw head angle affected the resulting preload force of the implant-abutment connection. The thread number had no effect. There was an approximately linear correlation between tightening torque and preload force. Conclusion The tightening torque and screw head angle were the only study parameters that affected the resulting preload force of the abutment screw. The results obtained from this experiment are valid only for a single torque condition. Further investigations are needed that analyze other parameters that affect preload force. Once these parameters are known, it will add value for a strong, but detachable connection between the implant and abutment. Short implants and flat-to-flat connections especially will benefit significantly from this knowledge.

Purpose: This study aimed to test bacterial microleakage at the implant-abutment interface (IAI) before and after dynamic loading using a new chewing simulation. Materials and Methods: Fourteen implant systems (n = 5 samples of each) were divided into two groups: (1) systems with conical implant-abutment connections (IACs), and (2) systems with flat IACs. For collecting samples without abutment disconnection, channels (O = 0.3 mm) were drilled into implants perpendicularly to their axes, and stainless-steel cannulas were adhesively glued inside these channels to allow a sterilized rinsing solution to enter the implant interior and to exit with potential contaminants for testing. Implants were embedded in epoxy resin matrices, which were supported by titanium cylinders with lateral openings for inward and outward cannulas. Abutments were tightened and then provided with vertically adjustable, threaded titanium balls, which were cemented using composite cement. Specimens were immersed in a bacterial liquid and after a contact time of 15 minutes, the implant interior was rinsed prior to chewing simulation (0 N ⩠ static seal testing). Specimens were exposed to a Frankfurt chewing simulator. Two hundred twenty force cycles per power level (110 in ± X-axis) were applied to simulate a daily masticatory load of 660 chewing cycles (equivalent to 1,200,000 cycles/5 years). The applied load was gradually increased from 0 N to a maximum load of 200 N in 25-N increments. The implant interior was rinsed to obtain samples before each new power level. All samples were tested using fluorescence microscopy; invading microorganisms could be counted and evaluated. Results: No bacterial contamination was detected under static loading conditions in both groups. After loading, bacterial contamination was detected in one sample from one specimen in group 1 and in two samples from two specimens in group 2. Conclusion: Controlled dynamic loading applied in this study simulated a clinical situation and enabled time-dependent analysis regarding the bacterial seal of different implant systems. Conical IACs offer a better bacterial seal compared with flat IACs, which showed increased microleakage after dynamic loading. IAC design plays a crucial role in terms of bacterial colonization. Taking samples of the implant interior without abutment disconnection eliminates an error source

A digital process is presented for an implant-supported single-tooth and a 3-unit fixed dental prosthesis (FDP) with customized abutments and monolithic prosthetic zirconia restorations. The digital impression on the implant level was made with a TRIOS intraoral scanner (3Shape). This process included the fabrication of an implant cast with the fused deposition modeling technique and a 3-dimensional printing process with integrated implant analogs. The process enabled the FDPs to be designed with CAD/CAM on the cast before patient contact. Designing a printed implant cast expands the use of the digital workflow in the dental field.

The aim of this clinical trial was to evaluate the marginal and internal fit of CAD/CAM fabricated zirconia crowns and three-unit fixed dental prostheses (FDPs) resulting from direct versus indirect digitalization. The efficiency of both methods was analyzed. In 25 patients, 17 single crowns and eight three-unit FDPs were fabricated with all-ceramic zirconia using CAD/CAM technology. Each patient underwent two different impression methods; a computer-aided impression with Lava C.O.S. (CAI) and a conventional polyether impression with Impregum pent soft (CI). The working time for each group was recorded. Before insertion, the marginal and internal fit was recorded using silicone replicas of the frameworks. Each sample was cut into four sections and evaluated at four sites (marginal gap, mid-axial wall, axio-occlusal transition, centro-occlusal site) under ×64 magnification. The Mann–Whitney U test was used to detect significant differences between the two groups in terms of marginal and internal fit (α = 0.05). The mean for the marginal gap was 61.08 μm (±24.77 μm) for CAI compared with 70.40 μm (±28.87 μm) for CI, which was a statistically significant difference. The other mean values for CAI and CI, respectively, were as follows in micrometers (± standard deviation): 88.27 (±41.49) and 92.13 (±49.87) at the mid-axial wall; 144.78 (±46.23) and 155.60 (±55.77) at the axio-occlusal transition; and 155.57 (49.85) and 171.51 (±60.98) at the centro-occlusal site. The CAI group showed significantly lower values of internal fit at the centro-occlusal site. A quadrant scan with a computer-aided impression was 5 min 6 s more time efficient when compared with a conventional impression, and a full-arch scan was 1 min 34 s more efficient. Although both direct and indirect digitalization facilitate the fabrication of single crowns and three-unit FDPs with clinically acceptable marginal fit, a significantly better marginal fit was noted with direct digitalization. Digital impressions are also less time-consuming for the dental practitioner and the patient. The results show that a direct, intraoral, digitalized impression technique is more accurate and efficient when compared with conventional impressions in fabricating single crowns and three-unit FDPs.

In Deutschland werden laut einer Schatzung der Deutschen Gesellschaft fur Implantologie (DGI) jahrlich etwa eine Million Implantate inseriert. Im Gegensatz zu den Anfangszeiten der dentalen Implantologie, als implantologische Eingriffe hauptsachlich von Oral- oder Mund-, Kiefer-, Gesichtschirurgen durchgefuhrt wurden, implantieren heutzutage viele Zahnarzte und Zahnarztinnen in eigener Praxis. Aufgrund der rapiden technischen Weiterentwicklung, der hohen Anzahl an verfugbaren Systemen und dem stetig zunehmenden Erfahrungsschatz und wissenschaftlichen Erkenntnisgewinn ist eine regelmasige Auseinandersetzung mit der aktuellen Studienlage ratsam.

Statement of problem Nonrigid retainer systems for removable implant superstructures are associated with negative effects such as rocking and increased load on the denture base. Rigid retainer systems such as telescopic crowns reduce these negative effects, but their fabrication demands highly skilled dental technicians and is therefore expensive. Whether a protocol with prefabricated retainers will reduce production time is unclear. Purpose The purpose of this prospective clinical trial was to evaluate a prefabricated telescopic retainer and a treatment protocol including the intraoral luting of a framework. Material and methods A total of 23 participants (15 women and 8 men with a mean age of 61.6 ±2.9 years) were included. After 3 dropouts, 21 removable dentures (9 mandibular and 12 maxillary) retained by 91 delayed loaded Ankylos implants were investigated. All implants were restored with prefabricated conically shaped abutments (SynCone-abutment). The prefabricated corresponding cone matrix was assembled intraorally into a metal frame with autopolymerizing resin. After a loading period of 3 years, a follow-up examination investigated the fit of the framework, the prosthetic aftercare, the technical failures, and the retention force. A questionnaire was used to evaluate participant satisfaction. In addition, laboratory fabrication time and costs were compared with those of individually fabricated restorations. Results One mandibular implant was lost after 25 months (survival rate, 98.9%). The removable dentures showed no apparent rocking and minimal prosthetic maintenance during the 36-month trial. No dentures required relining. The retention force was scored as good in 17 participants and high (with 6 implants in the maxilla) and low (with 2 implants in the mandible) in 2 participants each. No technical failures occurred. An assessment of laboratory fabrication time and costs revealed reduced time and costs. Patient satisfaction was significantly increased (P Conclusions The SynCone retainer presented a time- and cost-efficient treatment option with sufficient long-term retention for removable dentures and high patient satisfaction. Mandibular prostheses restored with 2 implants had limited success.

Soft tissue integration in the transmucosal zone of dental abutments supports the peri-implant tissues, improves esthetics, ensures soft tissue seal against microorganisms, and preserves crestal bone level. The aim of this literature review was to define the most favorable surface topography and macrodesign of the transmucosal zone of abutments to achieve optimal soft tissue seal. An electronic search of the PubMed/MEDLINE database was performed, seeking relevant English-language articles published between January 1, 2003, and October 11, 2014. The key terms implant abutment, surface topography, and soft tissue seal were used both singly and jointly with "AND" in this search. Additionally, a manual search was performed. Articles that did not distinguish between abutment and implant surfaces, investigated only 1-piece dental implants, or were systematic reviews were excluded, although 4 systematic reviews were studied to obtain background information. Out of a preliminary pool of 206 articles, 12 relevant articles were identified for final evaluation in addition to the 4 systematic reviews. These included 3 human studies, 3 animal studies, and 6 in vitro studies. The human histologic studies showed evidence of perpendicular insertion of human gingival fibroblasts into the treated abutment surface. Laser-ablated, hydrophilic, and oxidized titanium surfaces resulted in this type of attachment. Epithelial cells seem to slightly favor zirconia and polished titanium surfaces. Due to heterogeneity in the study designs, statistical methods, and reported results, meta-analysis of the data was not possible. Improvements in the surface topography and macrodesign of dental abutments might improve biocompatibility and adherence to soft tissue; however, manipulation of soft tissue and second-stage surgery could negate any advantages of the improved surfaces.

Purpose: The objective of the study was to investigate one-piece CAD/CAM abutments made of titanium and gold-cast UCLA-type abutments for contamination, processing marks and microgaps via scanning electron microscope.Material and Methods: Three groups with five identical abutments each were examined with a scanning electron microscope (LEO 1530 VP; Oberkochen, Germany) after cleaning using a steam jet and ethanol. Group 1 included custom CAD/CAM abutments (Atlantis™; Dentsply Implants, Molndal, Sweden). Group 2 included UCLA-type cast bases prior to casting (Astra Tech Cast Design 4.5; Dentsply Implants). Group 3 included the identical cast bases with a cast-on abutment (gold alloy).Results: Contaminants were found on all abutments of group 1, on 3 of 5 samples in group 2 and on 1 of 5 samples in group 3. Processing marks were visible on samples of groups 2 and 3. No microgaps were present in groups 1 and 2. For all group 3 cast-on abutments, large unfilled shrinking cavities with a horizontal extent between

BACKGROUND The implant-abutment connection (IAC) is known to be a key factor for the long-term stability of peri-implant tissue. PURPOSE The aim of the present in vitro study was to detect and measure the mechanical behavior of different IACs by X-ray imaging. MATERIALS AND METHODS A total of 20 different implant systems with various implant dimensions and IACs (13 conical-, 6 flat-, and 1 gable-like IAC) have been tested using a chewing device simulating dynamic and static loading up to 200 N. Micromovements have been recorded with a high-resolution, high-speed X-ray camera, and gap length and gap width between implant and abutment have been calculated. Furthermore, X-ray video sequences have been recorded to investigate the sealing capacity of different IACs. RESULTS Out of the 20 implant systems, eight implant systems with a conical IAC showed no measurable gaps under static and dynamic loading (200 N). By contrast, all investigated implant systems with a flat IAC showed measurable gaps under dynamic and static loading. X-ray video sequences revealed that a representative conical IAC had sufficient sealing capacity. CONCLUSION Within the limits of the present in vitro study, X-ray imaging showed reduced formation of microgaps and consecutive micromovements in implants with conical IAC compared to flat IACs.

Statement of problem The demand for occlusal devices to treat oral parafunction is rising. Conventionally, these occlusal devices are produced in the dental laboratory, which requires impressions and gypsum casts. Computer-aided design and computer-aided manufacturing (CAD-CAM) require fewer production steps and may offer greater comfort. Whether this is an improvement on conventional procedures is unclear. Purpose The purpose of this crossover clinical study was to examine whether a digital workflow is feasible for fabricating occlusal devices to treat oral parafunction and to compare CAD-CAM–fabricated occlusal devices with conventionally produced ones to determine whether the digital method provides better results. Material and methods Thirty participants wore digitally fabricated occlusal devices for 3 months and then conventionally produced occlusal devices for another 3 months or vice versa. The main target parameter was the participant's preference for 1 of the device types. Results Both types had specific advantages and disadvantages, but the differences in participants' preference were not statistically significant. After completing the 2 testing periods, 16 participants preferred the laboratory-made device, whereas 12 participants preferred the digital occlusal device. Two participants dropped out during the study. Conclusions Given the absence of statistically significant differences, the digitally fabricated device can be considered a suitable alternative to laboratory-made devices. Laboratory-made occlusal devices are now the gold standard. However, given the savings in terms of cost and treatment time, they may be replaced, particularly if the production process can be improved.

Die zahnarztliche Implantologie hat sich in den letzten 20 Jahren als bedeutende Disziplin in der Zahnheilkunde etabliert. Laut einer Schatzung der Deutschen Gesellschaft fur Implantologie werden in Deutschland derzeit jahrlich mehr als 1Million Implantate zum Ersatz fehlender Zahne inseriert. Dies betrifft vor allem altere Patienten. So fehlen laut der letzten Mundgesundheitsstudie (DMS‐IV, 2006) bei Senioren im Alter von 65–74 Jahren durchschnittlich 14,2 Zahne. Haufig handelt es sich hierbei um Schaltlucken, sodass die Totalprothese als Therapiemittel an Wichtigkeit verliert und ein festsitzender Zahnersatz meist relativ gut realisierbar ist. Fehlende Zahne werden zunehmend mithilfe von Implantaten ersetzt. Wahrend 1997 nur etwa 0,7% der Senioren Implantatkonstruktionen trugen, hat sich dieser Wert 2005 mit 2,6% mehr als verdreifacht.

Orofacial rehabilitation in maxillary aplasia but the premaxilla requires, beyond addressing the oronasal communication, facial functional-aesthetic and dental prosthetic reconstruction.The report of a now 42-year-old patient, born with maxillary aplasia, presenting for surgical rehabilitation in 2002 (at 33 years old), further elaborates this complex challenge.A staged approach that included velopharyngoplasty was performed on the patient in 2002; alternatively to a preformed fibula, 2 zygomatic fixtures were later inserted bilaterally to the malar bone, and premaxillary teeth were retained. Subapical mandibular alveolar osteotomy was performed to reposition the malaligned alveolar process and teeth. Augmentation from the iliac crest to the left congenitally hypoplastic mandible followed, its alveolar nerve running atypically lingual and outside the bone. The maxilla was rehabilitated by telescoped coverdenture on ceramic primary crowns, the mandible with all ceramic crowns on standard implants after orthodontic tooth-arch harmonization.A most satisfying result was obtained regarding chewing, speaking, and swallowing. The good phonation and pharyngeal control that was shown by the patient after velopharyngoplasty was retained. Visual analog scale showed enhanced patient satisfaction from 4 to 8, and oral health impact profile 14G decreased from 16 to 7 impairment scores. Zygomatic implants and ceramic galvano-telescoped coverdenture were shown to be reliable, eventually for similar cases, combined if necessary with orthodontics, orthognathic surgery, and standard implants.

Aim: The aim of the present study was to compare the survival rates of different materials for fixed partial dentures (FPDs). Materials and Methods: A total of 547 FPDs made of different materials delivered to 319 patients were studied retrospectively with a mean observation time of 9.3 years. Cast-metal, metal-ceramic, and all-ceramic FPDs were included in the study and compared. Results: The 10-year survival rate for cast-metal FPDs was 92.7%, for metal-ceramic FPDs, 76.2%, and for allceramic FPDs, 88.2%. No significant findings were reported regarding FPD materials and long-term survival rates. Conclusion: Unlike in previous studies, no significant difference between the survival rates of all-ceramic FPDs and FPDs made of other materials was found. These results may be due to modern manufacturing methods of FPD frameworks — in particular CAD/CAM technology, which facilitates optimized framework designs.

Purpose: The aim of the present study was to assess the biological and technical complication and survival rates of implants and prosthetic superstructures using custom-milled CAD/CAM abutments made of titanium or zirconia. Material and Methods: A total of 109 patients were treated with 225 AstraTech OsseoSpeed implants (Dentsply IH) between July 2008 and November 2012 in the same private dental practice. Following submerged healing, the implants were uncovered and restored with Atlantis custom CAD/CAM abutments made of zirconia or titanium. Single crowns, fixed bridges, or telescope crowns as attachments for removable prostheses were connected to the abutments with zinc oxide phosphate cement. Patients were clinically and radiologically followed at the abutment level for a mean 20.85 months. The clinical assessment included biological and technical complications a well as the survival of the implants, abutments, and prosthetic superstructures. Mean crestal bone loss was assessed on standardized radiographs. Patient satisfaction was surveyed with a self-developed questionnaire. Results: The records of 69 patients (49 female, 20 male: mean age: 53.51 years) treated with 124 implants/custom abutments were included in the final analysis. Most abutments were made of titanium (n=90), followed by zirconia (n=34). The survival rates of implants and abutments were 100.00%. Eight restorations (6.50%) had to be replaced during follow-up, for an implant/abutment-related cumulative prosthetic success rate of 93.50%. The patient-related cumulative prosthetic survival rate was 92.75%. A mean bone gain of 0.06 mm (SD: 0.28 mm) on the mesial side and 0.11 mm (SD: 0.37 mm) at the distal side of the implants (n=122) was recorded. Only a few cases of soft-tissue complications such as mucositis, loss of papilla height, or bleeding on probing were observed. Therapy was rated as very good by 92.65% of patients. The esthetic result was assessed as very good as well by the majority of patients (88.41%). Due to the small sample size, no tests for statistical significance could be performed for any of the examination parameters, except for radiological crestal bone loss. No statistical significance was found for crestal bone loss as a function of the abutment material (p ≥ 0.05). Conclusions: Individual CAD/CAM -abutments are a good and predictable treatment option and deliver high patient satisfaction concerning the therapeutic and esthetic results.

A prospective, randomized, controlled, split-mouth trial was performed to evaluate the cementation modes for metal-ceramic crowns. A total of 40 fully veneered metal-ceramic crowns were delivered in the posterior jaw segments of 20 patients using either a self-adhesive resin cement (RelyX Unicem Aplicap, 3M ESPE; n = 20) or a zinc oxide phosphate cement (Hoffmann's Cement, Hoffmann; n = 20). Thirteen parameters related to the abutment teeth and their periodontal status were evaluated. A visual analog scale was used to assess the sensitivity of the abutment teeth by patient-based outcomes. Data were statistically analyzed by a single-classification ANOVA (α = 0.05) and logistic regression analysis. The results presented were obtained after a mean observation period of 1.8 years. The dropout rate was 0%. None of the abutment teeth exhibited secondary caries at the restoration margins. No significant differences were demonstrated between the luting agents based on visual analog scale (p > 0.05), hypersensitivity (OR = 1.31), abutment mobility (p > 0.05), or probing depths (p > 0.05). Based on the sulcus fluid flow rates, a significantly greater mean difference was obtained with zinc oxide phosphate cement than with self-adhesive resin cement (9.2 units; p = 0.0006). Significant differences between the baseline examination and the follow-up examinations for sulcus bleeding index (p = 0.0013) and plaque index (p < 0.0001) were observed regardless of the luting agent used. The two cement types showed scarcely any differences between the parameters investigated. The outcomes of cementing fully veneered metal-ceramic crowns were equally good with self-adhesive resin cement as with the clinically proven zinc oxide phosphate cement.

Objectives Evaluation of the influence of professional competence on esthetic predictability of implant-supported crowns in the anterior maxilla and identification of objective factors allowing predictable planning for esthetic results. Materials and methods Sixty patients with 82 implants in the esthetic zone were included in this study. Width of keratinized mucosa, biotype, recessions, and papilla index according to Jemt as well as radiological bone loss were assessed. Study casts and photographs were obtained. Each patient as well as people with different level of expertise (laypersons, students and dentists) rated the esthetic satisfaction after final restoration on a scale (1–10). Correlations between esthetic assessments and previously documented clinical parameters were tested. Results The study failed to show a significant relationship between the raters' level of dental expertise and their subjective esthetic evaluation. However, patients rated themselves much more favorable than the three evaluator groups did. A comparison of the clinical parameters with the esthetic evaluation revealed significantly more favorable ratings by the lay group in the presence of a wide attached gingiva (P = 0.021) than by the other groups and by the laypersons (P = 0.002), the dentists (P = 0.003), and students (P = 0.009) in the absence of recessions. The ratio of the implant crown length to the length of the contralateral crown had a negative effect on ratings for all three groups ([laypersons P

To examine the long-term adhesion of seven dual-polymerizing cementing agents to human dentin in vitro.Two hundred and eighty extracted non-carious human molars were ground flat to expose dentin surfaces. The bond strengths of cementing agents with their respective bonding systems were examined: one compomer cement (PermaCem), five resin cements (RelyX ARC, Panavia F, Variolink II, Nexus 2, Calibra) and one self-adhesive universal resin cement (RelyX Unicem). One subgroup (n=10) was tested after 150 days of storage in water at 37 degrees C (time t(1)), the other subgroup (n=10) was tested after 150 days of storage plus 37,500 thermal cycles (time t(2)). All specimens were stressed in shear at a constant crosshead speed of 0.5mm/min until failure. Statistical analysis was performed by ANOVA, taking effect interactions into account. The Tukey method was used for multiple paired comparisons (alpha=0.05).The three-way ANOVA (cementing agents, polymerization methods, times of measurements) showed Variolink II to have the highest strength at 9.9+/-4.5MPa. Values were slightly higher at t(1) (5.9+/-4.7MPa) than at t(2) (4.9+/-4.2MPa) (p=0.0044). Polymerization with light activation (6.5+/-5.1MPa) yielded higher strengths than polymerization without (4.3+/-3.3MPa) (p0.0001). Separate two-way ANOVAs for t(1) and t(2) showed that the two main effects (cementing agent, polymerization method) and their interactions differed significantly.Cementing agents/adhesive systems and the polymerization method influence the long-term bond to hard dental tissues.

Aim To estimate the correlation between the MRI findings and clinical outcomes in patients with temporomandibular joint dysfunction (TMD). Methods and materials We included 546 female and 248 male patients who were clinically diagnosed with TMD (mean age 38.7 years) and examined by MRI (T1 and T2 weighted images, parasagittal and paracoronal slices). A questionnaire, radiological, and clinical findings were analysed for statistically significant correlations. The analysed parameters included gender, age, disk position, joint degeneration, arthralgia, mouth opening, condyle position and clinical progress. Results Of all TMJ’s 62% showed physiological disc position, 35% anterior and 3% posterior disc position. Modification of therapy occurred in 20% and alteration of diagnosis was found in 32% of all cases. Anterior disc displacement with reduction showed a specificity of 88% and a sensitivity of 78%, whereas anterior disc displacement without reduction showed a specificity of 84% and a sensitivity of 73%. A significant correlation between disc length, condyle morphology and disc displacement was found. With the increase of intra-articular liquid as seen on MRI the level of arthralgia significantly rose as opposed to mouth opening. Conclusion Specificity and sensitivity, for anterior disc displacement and osseous changes in TMJ were highly acceptable. Results had confirmed the diagnostic capability of MRI in diagnostic imaging of TMJ. Additionally MRI should be used primarily in severe, therapy-resistant cases and for surgical planning purposes.

Objectives To evaluate microleakage and marginal gaps in full cast crown restorations bonded with six different types of cementing agents. Methods Sixty non-carious human premolars and molars were prepared in a standardized manner for full cast crown restorations. The mesial and distal margins were located in dentin, while the vestibular and palatal/lingual margins were located in enamel. Crowns were made from a high-gold alloy using a standardized technique. The specimens were randomized to six groups of cementing agents: one zinc-phosphate cement (Harvard cement), one conventional glass–ionomer cement (Fuji I), one resin-modified glass–ionomer cement (Fuji Plus), two standard resin cements (RelyX ARC, Panavia F), and one self-adhesive universal resin cement (RelyX Unicem). After 4 weeks of storage in distilled water at 37°C, the specimens were subjected to 5000 thermocycles ranging from 5 to 55°C. Then, they were placed in a silver nitrate solution, embedded in resin blocks, and vertically cut in buccolingual and mesiodistal direction. Subsequently, the objects were evaluated for microleakage and marginal gap using a high-resolution digital microscope camera. Results A number of inter-group differences were statistically significant. RelyX Unicem showed the smallest degree of microleakage both in enamel and in dentin. Panavia F und RelyX Unicem were associated with significantly larger marginal gaps than all other cementing agents. No association was observed between microleakage and marginal gap other than a weak direct correlation when using Harvard cement on enamel. Significance The cementing agents investigated revealed different sealing abilities. These differences were not associated with specific types of materials.—Reprinted with permission of The Academy of Dental Materials.

PURPOSE The study evaluates the compressive, flexural, and diametral tensile strengths of 8 core build-up materials from different material classes (highly viscous glass ionomer cement, autocured resin composite, and compomers). MATERIALS AND METHODS All materials were manipulated according to the manufacturers' recommendations for use as core materials. At a temperature of 23.0 +/- 1.0 degrees C the properties of compressive, diametral tensile and flexural strength were determined using a universal testing machine at 15 minutes, 1 hour, and 24 hours after material preparation. Using one-way analysis of variance (ANOVA), multiple mean value comparisons were performed to determine significant differences (p< or =.05) between the core restoration materials. RESULTS The values for compressive strength varied from 40.3 +/- 5.2 MPa (compomer) to 237.4 +/- 37.3 MPa (autocured resin composite) for the 3 measurement times. At 15 minutes, 1 hour, and 24 hours after first mixing, the ANOVA showed significant differences (p < or =.05) between the resin composite Core Paste and all of the other materials. Diametral tensile strengths ranged from 5.5 +/- 1.1 MPa for glass ionomer cement to 39.1 +/- 2.9 MPa for composite core material. Three-point flexural strength showed values ranging from 12.1 +/- 2.5 MPa for glass ionomer cement to 92.1 +/- 9.7 MPa for compomer between the 3 measurement times. CONCLUSIONS Setting time influences the mechanical properties of the materials tested in this study. Autopolymerizing resin composite Core Paste demonstrated greater compressive and flexural strengths at the 3 measurement times than the other materials tested. Reinforced composites, in comparison to the autocured resin composites, yielded no improvement in tensile strength. Flexural and tensile strengths of the glass ionomer cement were lower than those of autocured resin composites and compomers.

This prospective randomized clinical trial aimed to evaluate the long-term behavior of metal-free double crown retained dentures with secondary crowns and dental frameworks made of the fiber-reinforced composite Vectris(©) on all-ceramic primary crowns (IPS Empress 2(©)) over a period of up to 14 years and to subsequently evaluate patient satisfaction. For the control group, electroplated gold copings and metal frameworks were used.A total of 29 patients were treated with a total of 37 prostheses on 165 primary crowns. Of these 37 prostheses, 27 were allotted to the control group and 10 to the test group. The mean observation time was 91 ± 57 months; patient satisfaction surveys were conducted over 77 ± 59 months.Success rates in both groups were compared using Kaplan-Meier survival curves and log-rank test. Up to about 3 years, both types of prostheses exhibited similar success rates. Afterwards, a massive decrease in the Vectris(©) curve could be noted, whereas the metal curve dropped only slightly. This difference was also statistically significant (p = 0.032361). There was a comparable susceptibility to damages in both groups: 88.9 % (control) and 90 % (test), respectively, of the prostheses had to be repaired within the period of investigation (p = 0,121). Damages of the Vectris(©) secondary crowns could be detected significantly more often compared to the electroformed gold copings (p 0.00005). Patient satisfaction with the restorations was comparably high in both groups.Metal-free secondary crowns and denture frameworks made with the glass fiber-reinforced composite material Vectris(©) showed a lower survival rate than the electroplated gold copings and metal frameworks. Primary crowns made of IPS Empress 2(©) had insufficient stability. Exclusively high-strength zirconia ceramics should be recommended for this indication.Both clinical and statistical data indicated the superiority of the restorations made with electroplated secondary crowns and metal framework. Therefore, the use of Vectris(©) cannot be recommended for the fabrication of double crown retained removable dentures as permanent restorations.

Aims: To carry out a systematic review and meta-analysis comparing the effects of occlusal splint therapy ("usual treatment") and psychosocial interventions for the treatment of myofascial temporomandibular disorder (TMD) pain in adult patients. Methods: Independent screening and evaluation of randomized clinical trials included comparisons between "usual treatment" based on splint therapy and psychosocial interventions for TMD treatment within electronic databases (PubMed/MEDLINE, CENTRAL, EMBASE), ongoing trials databases (Current Controlled Trials, ClinicalTrials.gov), and additional sources. The outcomes selected for the systematic review were self-reported pain, pain interference, unassisted jaw opening without pain, muscle pain upon palpation, depression, and somatization. The effect measures were analyzed using a random-effect model (Review Manager computer program). Results: The outcomes "longterm self-reported pain" and "long-term depression" were significantly different for the comparisons of "usual treatment" and psychosocial interventions, and they favored the latter (P < .005 and P < .05, respectively). These results must be viewed with caution due to the limited number of studies available. A tendency toward greater improvements of psychological outcomes was observed for psychosocial interventions, while physical functioning was slightly more responsive to "usual treatment." Conclusion: No evidence was found to distinguish the clinical effectiveness between "usual treatment" and psychosocial interventions for myofascial TMD pain. Future studies of TMD and related subdiagnoses should be reported according to core standardized outcomes to facilitate comparisons.

The aim of this study was to evaluate the effect of controlled intraoral grinding and polishing on the roughness of full-contour zirconia compared to classical veneered zirconia. Thirty bar-shaped zirconia specimens were fabricated and divided into two groups (n=15). Fifteen specimens (group 1) were glazed and 15 specimens (group 2) were veneered with feldspathic ceramic and then glazed. Prior to grinding, maximum roughness depth (Rmax) values were measured using a profilometer, 5 times per specimen. Simulated clinical grinding and polishing were performed on the specimens under water coolant for 15 s and 2 N pressure. For grinding, NTI diamonds burs with grain sizes of 20 µm, 10 µm, and 7.5 µm were used sequentially. The ground surfaces were polished using NTI kits with coarse, medium and fine polishers. After each step, Rmax values were determined. Differences between groups were examined using one-way analysis of variance (ANOVA). The roughness of group 1 was significantly lower than that of group 2. The roughness increased significantly after coarse grinding in both groups. The results after glazing were similar to those obtained after fine grinding for non-veneered zirconia. However, fine-ground veneered zirconia had significantly higher roughness than venerred, glazed zirconia. No significant difference was found between fine-polished and glazed zirconia, but after the fine polishing of veneered zirconia, the roughness was significantly higher than after glazing. It can be concluded that for full-contour zirconia, fewer defects and lower roughness values resulted after grinding and polishing compared to veneered zirconia. After polishing zirconia, lower roughness values were achieved compared to glazing; more interesting was that the grinding of glazed zirconia using the NTI three-step system could deliver smooth surfaces comparable to untreated glazed zirconia surfaces. Non-veneered zirconia crowns respond well to clinical polishing leaving a smooth finish to help combat decay, research from Germany states. Zirconia (zirconium oxide) is a high-strength material commonly used for all-ceramic tooth restoration. Zirconia crowns are often veneered with dental porcelain but the veneer is prone to chipping, particularly during the clinical polishing and grinding carried out after dental restoration procedures. The resulting rough surfaces can wear down opposing teeth and attract plaque. Rim Hmaidouch and co-workers at the Johann Wolfgang Goethe University in Frankfurt tested the effect of polishing and grinding on zirconia crowns with and without veneers, aiming to find the best quality finish. They found that, after grinding and polishing procedures, glazed zirconia with no porcelain veneer had fewer defects and less surface roughness than veneered zirconia.

PURPOSE The present in vitro study examined 3 mechanical properties, namely compressive, flexural, and diametral tensile strength, of various commercially available cements and core materials as a function of time after mixing. MATERIALS AND METHODS The examined materials were 2 cermet cements (Ketac Silver [ESPE, Seefeld, Germany] and Chelon Silver [ESPE]), 1 metal-reinforced glass ionomer cement (Miracle Mix [GC Dental Industrial Corp, Tokyo, Japan]), 2 conventional glass ionomer cements (Ketac Bond [ESPE] and Ketac Cem [ESPE]), 1 standard cure zinc phosphate cement (Harvard Cement [Richter and Hoffmann, Berlin, Germany]), and 1 zinc phosphate cement with the addition of 30% silver amalgam alloy powder (Harvard Cement 70% with Dispersalloy 30% [Richter and Hoffmann/Johnson and Johnson, East Windsor, NJ]). Properties were measured using a universal testing machine at 15 minutes, 1 hour, and 24 hours after first mixing. RESULTS Compressive strengths varied widely between the 3 times of measurement from 5.8 +/- 6.6 MPa for Ketac Cem to 144.3 +/- 10.2 MPa for Ketac Silver. Twenty-four hours after mixing, the Bonferroni test showed significant (p

Removable dentures supported by cast-metal telescopic crowns often exhibit an unpredictable increase or decrease in retentive force after being in clinical use for some time. The objective of the present in vitro study was to develop a new retainer for removable dentures and to evaluate its tribological properties. The new retainer is based on a tapered crown design and consists of a conical all-ceramic abutment crown and a coping made of electroplated gold. It was compared with conventional telescopic retainers made of cast metal. There were 30 specimens in groups of equal size by material used (abutment crown/coping): Group 1, gold/gold; Group 2, titanium/titanium; Group 3, ceramic/electroplated gold. Each specimen consisted of 2 conical-shaped abutment crowns (alpha =4 degrees; h = 6 mm; O(base) = 4,5 mm); their copings were rigidly connected at 25 mm intervals. Retentive forces were measured with a universal testing machine following axial loading to 5-400 N. Wear was simulated by 500-100, 000 joining and separating cycles in the presence of artificial saliva. Metallographic cross-sections were made to evaluate the specimens' fit and surfaces with an SEM. Retentive forces in Groups 1 and 2 increased with load, exhibiting nondirectional changes after induced wear. Sometimes the alloys' functional surfaces showed considerable tracks of wear. Neither load nor wear had any effect on Group 3 retentive forces (mean(force) = 5.03 N). The functional ceramic and gold surfaces showed no traces of wear and the best fit (median(gap) = 4.9 microm). Replacing cast metals by ceramics and electroplated gold results in retainers with clinically advantageous tribological effects, implying, in particular, high wear resistance.

Treatment of an edentulous mandible is an important standard area of indication for implants. The aim of the present study was to discuss various aspects of this very important topic using a literature research and possibly derive a recommendation for hybrid prosthetic treatment of the edentulous mandible. Though evaluation of the literature produced a large number of publications with case histories and survival rates, there were only a few prospective randomised clinical studies that compared different treatment concepts in the edentulous mandible to allow an evidence-based statement. Despite all the limitations imposed on the interpretation of the study, the following statements could be made with regard to implant-supported dentures in the edentulous mandible: Two implants represent the easiest, most inexpensive treatment and are adequate for stabilizing a denture in an edentulous mandible. This type of restoration is easy to maintain for the patient with regard to oral hygiene and surgery stress is reduced to a minimum. The disadvantages of this treatment are increased mobility and instability of the denture in the dorsal region. Apart from increased intraoral comfort, the advantages of treatment using four implants include the stable fit of the denture and the option of immediate restoration.

When determining the horizontal jaw relation and mandibular movements, a question arises as to the appropriate choice of registration positions. The current study was carried out using 22 adults with full dentition who did not have any discomfort in their skeletal and craniomandibular systems. Occlusion and mandibular movements were investigated with open and closed eyes in standing and sitting positions using an electronic, central-bearing tracing device. The coordinates of the measured parameters are presented using a two-dimensional computer vector diagram. The non-parametric Friedman test was used for statistical data analysis. The measured data obtained for the initial habitual centric relation record (HR), centric relation record (CR), final habitual centric relation record (HR), and protrusion (P) did not significantly differ in the sitting and standing positions or with opened and closed eyes (p = 1.00). With closed eyes, the differences in the average values between the two condylar positions (initial HR/final HR, initial HR/CR, and final HR/CR) decreased in a manner that was independent of the registration position. The CR that was measured in a sitting position with closed eyes was 2.26 mm more retrusive than that measured with open eyes. Before and after CR measurements, only laterotrusion showed significant differences (p=0.02) in patients who were standing with closed eyes. It was concluded that the registration position and visual system could individually influence the measurements of condylar position and mandibular movements. From a clinical perspective, these measurements exhibited the smallest differences when they were conducted with patients in a sitting position with closed eyes.

Influenza viruses are highly contagious. Medical personnel are at risk of occupational exposure to influenza. Data on dental healthcare workers (DHCWs) immunization status has not been published. We conducted a cross-sectional survey of DHCWs and dental students at a German dental university hospital. Surveys, completed between October 2010 and March 2011, focused on reasons of DHCWs for accepting or declining the influenza vaccination. Furthermore, we characterized attitudes towards influenza infection due to the emergence of the H1N1/2009. Compliance rates with the influenza vaccination among DHCWs were low (31.6%). The main reason for not getting vaccinated against the pandemic influenza A/H1N1 virus in the 2009/2010 season was the objection to the AS03-adjuvants (48.5%). Of the DHCWs surveyed, 30.6% (74/242) cited that the H1N1/2009 pandemic influenced their attitudes towards vaccination in general. Our findings confirm the importance of a comprehensive approach to the influenza vaccination, ensuring that DHCWs are correctly informed about the vaccine and that it is convenient to receive it. It could be shown that an immunization campaign at the workplace seems to be capable of improving vaccination rates, one-third of the vaccinees have been vaccinated for the first time.

The addition of epinephrine in dental local anaesthesia results in a longer and deeper anaesthesia under almost ischemic conditions. For short-time dental treatments, epinephrine-reduced anaesthetics may offer shorter and more individual anaesthesia with reduced potential side effects. The aim of this study was a clinical evaluation of anaesthetic potency and adverse effects of an epinephrine-reduced articaine formulation in dental patients undergoing short-time routine treatment. In a prospective clinical, not interventional, study between January 2008 and February 2009, 908 patients undergoing short-time dental treatment in five medical centers were anaesthetized with 4% articaine 1:400,000 epinephrine (Ubistesin™, 3M/ESPE, Seefeld, Germany). Efficacy and safety in clinical use were evaluated. A follow-up after 1 day was conducted by telephone survey. A mean amount of 1.3-ml anaesthetic solution was needed to achieve a complete or sufficient anaesthesia in 97% (n = 876) of cases. A second injection had to be done in 3.7% (n = 34) before and in 11.9% (n = 108) during treatment. Here, the second injection had to be applied after a mean of 48.6 min. The mean duration of soft tissue anaesthesia after infiltration was 146.6 min, after nerve block 187.7 min. The painful treatment took a mean of 50.2 min and the total treatment time summed up to 68.8 min. In 1.7% cases (n = 15), unwanted side effects were observed. The results indicate that a lower concentration of epinephrine in combination with the 4% articaine solution leads to a high success rate of efficacy. The clinical use of a 4% articaine 1:400,000 epinephrine solution can be stated as safe and effective in short dental routine treatments. Reconsiderations concerning limitations of indication or additional contraindications are not necessary.

This study presents successful maxillofacial prosthetic rehabilitation using telescopic and crowns on zygoma implants as abutments.Fifteen patients received 36 zygomatic and 24 dental implants and were followed-up for an average of 65 months (range: 13 to 102 months). Machined zygoma implants were positioned classically in the maxillary molar region. In larger defects, premolar and canine implants were also used. Follow-up included implant and prosthetic success parameters as well as the completion of the Oral Health Impact Profile (OHIP14G).Seventy-three percent of patients during the study period did not encounter notable complications after prosthetic rehabilitation. There was an 89% cumulative 8-year zygoma implant survival rate and a 100% survival rate for the dental implants. Three losses occurred due to overloading and persistent infection; each was immediately replaced. Five successfully osseointegrated implants had to be removed in two patients due to recurrences of disease; one patient died. Peri-implant bleeding and plaque index scores decreased. After prosthetic treatment with electroplated gold or galvanotelescopes, all patients who had participated in the follow-up declared function (i.e., retention, speech, and mastication) and esthetics as having improved. Other positive aspects mentioned were good hygiene, comfortable usage, and a decrease in sore spots. OHIP scores were 25 +/- 12 on a scale of 0 (no impairment) to 56 (maximum impairment).Within the limitations of this study (a variable evaluation period), it was observed that zygomatic implants are reliable retention for maxillofacial prostheses. Losses were diagnosed as occuring primarily from chronic infection and overloading. A trapezoid prosthesis design support is recommended with a sufficient number of implants.