Clinical application of fully digital Cerec surgical guides made in-house.

It is now possible to produce full-digital drilling templates with Cerec Guide 2 (Sirona) in the dental practice relatively quickly, efficiently, and economically. Here, a patient case example is used to present an exemplary description of the procedure and method to do this. The solution described herein shows the advantageous efficiency, compared with other systems presently on the market, of a procedure that does not require the external production of the drilling template in the laboratory or a manufacturing center.

Cerec reconstruction of a hemisected mandibular molar: method and case report.

Hemisection of mandibular molars is a viable method of preserving periodontally or endodontically compromised teeth or roots. This paper describes a simple chairside CAD/CAM method of fabricating a cantilever crown for a hemisected molar. The technique is illustrated by a clinical case, which was treated according to this protocol and was followed-up over 2.5 years. Given careful patient selection and strict recall intervals, the introduced method represents a conservative and cost-effective treatment modality for high-quality ceramic reconstructions of root-resected teeth. In addition, other treatment options such as implantation or prosthesis, which would represent therapeutic and prosthetic endpoints, can be postponed.

Digital 3-D implant planning: Cerec meets Galileos.

Prosthetically based implant planning is necessary so that implants are set expediently and correctly during surgery. A clinical case is presented to describe how this can be performed today purely digitally. Prosthetic planning was undertaken with the Cerec CAD/CAM system. The data record created was transferred and superimposed on a CBCT 3-D radiograph. The position of the implant was planned taking the prosthetic planning into account.

[Therapy-resistant depression with fatigue. A case of presumed streptococcal-associated autoimmune disorder]. / Therapieresistente Depression mit Fatigue. Fall einer vermutlichen streptokokkenassoziierten Autoimmunkrankheit.

After a tick bite and erythema chronicum migrans, a 31-year-old patient developed headaches, fatigue, multilocular pain and therapy-resistant depression with cognitive disturbances. Antibodies against Borrelia and Borna disease virus, high antibody titers against streptococci at the point of most severe depression and blood-CSF barrier dysfunction were found. Streptococcal antibody titers were normal 2 years before and 4 years after. With penicillin treatment and tonsillectomy, therapy-resistant depression improved. We suggest that the whole syndrome was streptococcal-associated autoimmune disease.

Thin-wall ceramic CAD/CAM crown copings: strength and fracture pattern.

The strength and fracture pattern of posterior CAD/CAM-generated crown copings with 0.4 mm wall thickness were evaluated in vitro hypothesizing that fracture resistance of YTZP-zirconia copings might be independent of mode of cementation whether resin-bonded or cemented because of the high strength of YTZP-zirconia. Two sets of copings (n = 15) each were fabricated using CEREC inLab CAD/CAM from (i) lithiumdisilicate glass-ceramic, (ii) infiltration ceramic as controls and (iii) YTZP-zirconia. Copings (n = 15) of ceramics (i), (ii) and (iii) each were (a) zinc-phosphate cemented, (b) adhesively seated on resin-based composite dies and loaded until fracture. Load (N) data was analysed using anova and Scheffé tests. Crack pattern was evaluated on additional three sample cross-sections for each group at fracture-start. Radial cracks originated early at the cementation interfaces and cone cracks were observed finally at the loading sites. Mean load (N) values (+/-s.d.) of A-copings at fracture-start/-end (i) 804 +/- 195/862 +/- 162, (ii) 923 +/- 180/975 +/- 147, (iii) 697 +/- 110/1607 +/- 145, were all significantly (P < 0.01) lower when compared with their B-crown coping analogs (i) 1183 +/- 318/1919 +/- 326, (ii) 1621 +/- 165/1820 +/- 211, (iii) 731 +/- 115/1973 +/- 287 except for A3 and B3 at fracture-start. This confirmed our hypothesis at fracture-start (P > 0.05) but rejected it at fracture-end (P < 0.01). The A3 fracture-end data, even if significantly (P < 0.01) lower, came close to the B3 values by 18%. A3 was significantly (P < 0.001) stronger by 86/74% than A1/A2 at fracture-end. The data indicates that YTZP-zirconia copings have the potential to provide support for all-ceramic core crowns, which may be adequate for non-adhesive cementation.

Marginal and internal fit of all-ceramic CAD/CAM crown-copings on chamfer preparations.

Evaluation of the marginal and internal fit of all-ceramic molar crown-copings hypothesizing that Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) fabrication shows the same accuracy of fit as conventional techniques. A set of six individual crown preparations was duplicated 12 times yielding 72 plaster dies. Slip-cast (In-Ceram Zirconia), heat-pressing (Empress II) and CAD/CAM crown-copings (Cerec inLab, DCS, Decim and Procera) were seated on 12 dies each. Marginal and internal gap width was measured in the SEM at 120x magnification. Marginal gap of slip-cast (25 +/- 18 microm) was significantly (P < 0.05) smaller than that of Empress II (44 +/- 23 microm) copings. Procera (17 +/- 16 microm) and Decim (23 +/- 17 microm) did not differ (P > 0.05) from slip-cast (25 +/- 18 microm) but were smaller (P < 0.001/P < 0.01) than Empress II (44 +/- 23 microm) and Cerec inLab (43 +/- 23 microm) (P < 0.001/P < 0.05). DCS (33 +/- 20 microm) did not differ (P > 0.05) from any of the others. The internal mid-orobuccal gap width of Procera (136 +/- 68 microm) was larger (P < 0.001) than that of Decim (81 +/- 30 microm) and slip-cast (94 +/- 84 microm) (P < 0.05) while Empress II (105 +/- 53 microm), DCS (110 +/- 79 microm) and Cerec inLab (114 +/- 58 microm) did not differ significantly (P > 0.05) from Decim, Procera and slip-cast. Internal mesiodistal gap width was similar. The fit of conventional and CAD/CAM all-ceramic molar crown-copings covered the same range of gap width confirming the assumed hypothesis.

Flexural strength of Cerec 2 machined and jointed InCeram-Alumina and InCeram-Zirconia bars.

OBJECTIVE: The flexural strength of Cerec 2 InCeram-Alumina and InCeram-Zirconia bars is evaluated. The focus of the in vitro study is to identify a jointing procedure for InCeram which may be used for producing full-ceramic fixed-partial-denture frameworks. METHODS: Six groups (n=15) of machined and jointed InCeram-Alumina (T1-T5) and InCeram-Zirconia (T6) bars (3x4x13mm(3)), respectively, were examined using a 3-point-bending test. InCeram-Alumina joint-free controls were: machined (C1), slip cast (C2, C3) and cut from the block (C4) bars. Machined joint-free InCeram-Zirconia bars were used as controls (C5). InCeram-Alumina slip was used for jointing T1-T5 and InCeram-Zirconia slip for bars T6. Bars were jointed in groups T1 and T2 using butt joint (S1), in T3 and T4 oblique (S2, S3) and in T5 and T6 rounded (S4) joint shapes. RESULTS: Two-way analysis of variance showed significant differences between materials (p<0.001) and jointing shapes (p<0.001). The rounded (S4) shape showed the highest flexural strength of 434 (65) MPa of InCeram-Alumina (T5) and 475 (54) MPa of InCeram-Zirconia (T6) bars, respectively but machined/joint-free InCeram-Alumina (511 (59) MPa, C1) and machined/joint-free InCeram-Zirconia (624 (58) MPa, C5) were significantly (p<0.01/p<0.001) stronger. No significant differences (p>0.05) were found between machined/jointed InCeram-Zirconia (475 (54) MPa, T6), joint-free InCeram-Alumina slip cast (498 (125) MPa, C2) and joint-free InCeram-Alumina machined bars (511 (59) MPa, C1). SIGNIFICANCE: Compared to conventional slip cast InCeram-Alumina the flexural strength of machined/jointed InCeram-Zirconia appears to be adequate for fixed-partial-denture frameworks.

The Cerec 3--a quantum leap for computer-aided restorations: initial clinical results.

The Cerec 3 system simplifies and accelerates the fabrication of ceramic inlays, onlays, veneers, and quarter, half, and complete crowns for anterior and posterior teeth. Cerec 3 software simplifies occlusal and functional registration. Proper occlusion is established accurately and quickly; manual adjustment is reduced to a minimum. The separate grinding device, working true to morphologic detail and with fine surface quality, is connected to the optical unit by radio control. Equipped with a laser scanner, it can also be used for indirect application through a standard personal computer. The Cerec 3 system is network and multimedia ready and, in combination with an intraoral color videocamera or a digital radiography unit, can be used for patient education and for user training. The Cerec 3 system thus is a diagnostic, restorative, training, and documentation center for the dental practice.

Clinical evaluation of adhesively placed Cerec endo-crowns after 2 years--preliminary results.

PURPOSE: Non-vital endodontically treated posterior teeth with complete loss of coronal hard tissues were prepared with a circular equigingival butt margin and central retention cavity of the entire pulp chamber ("endo-preparation"). Computer-generated ceramic corono-radicular restorations (Cerec endo-crowns) were bonded to these preparations. The purpose of this study was to evaluate the survival rate and the clinical quality of CAD/CIM endo-crowns after 2 years. MATERIALS AND METHODS: 19 Cerec endo-crowns (4 premolars and 15 molars) in 13 patients were examined using modified USPHS criteria at baseline and after an average time of 26 months. The ratings of the two examinations were compared. RESULTS: The service time of the 19 endo-crowns was 14 to 35.5 (mean +/- SD: 26 +/- 6) months. One molar endo-crown failed after 28 months because of recurrent caries. CONCLUSION: The overall clinical quality of the Cerec endo-crowns was very good, and so far, the clinical concept appears feasible.

Full-ceramic CAD/CIM anterior crowns and copings.

The purpose of the investigation was to examine the marginal and internal fit of Cerec anterior crowns and crown copings. The marginal and internal fit of Cerec anterior crowns (n = 18) and copings was examined on each of six anterior model tooth preparations, with different types of butt-margin crown preparation design on different teeth: 1.) straight flat (tooth 22), 2.) following the CEJ with mid-approximally steep curvature angles of 90 degrees mesial and 40 degrees distal (tooth 21) and 3.) same as 2, but with obtuse angles of 130 degrees and 150 degrees (tooth 41). The anterior crowns were machined on Cerec 2 units using Mark II ceramic (Vita), and the Cerec copings using In-Ceram Spinell (Vita). Laboratory slip-cast In-Ceram spinell anterior crown copings served as controls (n = 18). All reconstructions were seated (with adhesive) on the preparations, and the width of the marginal interface was measured circumferentially using SEM at 150x magnification. After cross-sectioning all samples in the bucco-oral direction, the internal fit was measured using this same technique. The marginal width of computer machined Cerec CAD/CIM anterior crowns (59.9 +/- 5.6 microns) was significantly (p < 0.01) lower than that of machined (73.4 +/- 12 microns) and slip-cast In-Ceram spinell copings (75.5 +/- 17 microns). The internal fit values of the slip-cast copings (94.1 +/- 20 microns) were significantly (p < 0.001) lower than those of the Cerec Mark II anterior crowns (141.3 +/- 21 microns) and copings (146.8 +/- 17 microns). Cerec CAD/CIM machined anterior full-ceramic crowns and copings showed excellent fit in comparison with slip-cast In-Ceram spinell copings. In terms of the marginal and internal fit, there were no significant differences (p > 0.05) between the different butt-margin preparation designs. Selected clinical cases demonstrate the high esthetics of anterior Cerec crowns.

Effects of preparation and luting system on all-ceramic computer-generated crowns.

PURPOSE: Computer-aided design/computer-integrated machining (CAD/CIM) allows defect-oriented custom-shaping of the inside surfaces of all-ceramic crowns. The purpose of this study was to examine the effect of inside crown form on fracture strength of cemented and bonded crowns. MATERIALS AND METHODS: Four preparation types were used: (1) "classic" with a butt shoulder of 1.2 mm, abutment height of 4 mm, and 6-degree convergence, (2) like type 1 with mesio-occlusodistal cavity, (3) like type 1 with height reduced by 50%, and (4) like type 1 with abutment reduced by 100% plus a pulp chamber cavity. Crowns were CAD designed on preparations 1 to 4 using identical outside morphology. Machined crowns were placed on abutments (a) without any media as controls (n = 15), (b) cemented (n = 15), and (c) bonded (n = 15), and were loaded until fracture. RESULTS: Zinc phosphate-cemented crowns (1b, 2b, 3b, and 4b) showed significant (P < 0.001) increase of fracture load values compared to uncemented control crowns (1a, 2a, 3a, 4a). Fracture load values of bonded crowns (1c, 2c, 3c) were significantly (P < 0.001) higher than those for cemented crowns. Bonded crowns with thick occlusal dimensions (3c and 4c) showed the highest fracture load values. CONCLUSION: Bonded all-ceramic CAD/CIM crowns with defect-oriented inside morphology and increased occlusal dimensions showed high fracture load values.

Phototoxic properties of neuroleptic drugs.

BACKGROUND: Photo-induced eruptions are well-known adverse effects of some neuroleptic drugs, particularly chlorpromazine. OBJECTIVE: By a photohemolysis test we assessed in vitro the phototoxic properties of 12 phenothiazines (chlorpromazine, dixyrazine, fluphenazine, levomepromazine, perazine, perphenazine, promazine, promethazine, prothipendyl, thioridazine, trifluoperazine, triflupromazine) and 5 thioxanthenes (chlorprothixene, clopenthixol, flupenthixol, thiothixene, zuclopenthixol). METHODS: Human erythrocytes from 3 donors were incubated with the compounds and irradiated with light sources rich in UVA or UVB, respectively. Doses were up to 100 J/cm2 UVA or up to 1,600 mJ/cm2 UVB. Photo-induced hemolysis was calculated as percentage of complete hemolysis. RESULTS: Photo-induced hemolysis >10% due to radiation rich in UVA was found with chlorpromazine (maximal median: 98%), dixyrazine (100%), fluphenazine (84%), perazine (100%), perphenazine (100%), promazine (16%), promethazine (25%), prothipendyl (96%), trifluoperazine (100%), triflupromazine (76%), chlorprothixene (100%) and thiothixene (31%). UVB-rich radiation induced hemolysis only with chlorpromazine (73%), dixyrazine (45%) and perazine (60%). CONCLUSION: Most neuroleptics are strongly phototoxic in vitro indicating a potential risk for photo-induced reactions also to occur in patients treated with these drugs.

The new creativity in ceramic restorations: dental CAD-CIM.

The efficiency of the Cerec 2 system, introduced in September 1994, is briefly presented. The system provides improved accuracy of fit, an automatically generated occlusion, free (unrestricted) cavity design, unlimited anatomic veneer preparation with incisal edge coverage, and automated and simplified operation.