International Poster Journal of Dentistry and Oral Medicine, 04/2004

Aim: The aim of this study was the evaluation of long term results of the treatment concept 'immediate loading' in the anterior mandible and the examination of different factors which exert influence on the success. Material and method: A total number of 321 implants were inserted in 74 patients and were splinted with a bar directly after surgery and restored with an overdenture within 24 hours. Clinical and radiological examinations were performed. Results: The recorded parameters approve overall healthy hard and soft tissue conditions. More than 90% of the implants do not show any inflammation. The vertical bone loss, determined at the last recall, amounted a mean value of 0.55 mm. The acquired survival rate is 99.03% for a maximum observation period of 659 days (median period 10.3 months). Depending on the crestal level at insertion there could also be observed a gain of crestal bone. A significant correlation between vertical bone loss and age, recall interval, kind of prosthetic restoration of the maxilla and mandible could be demonstrated with an univariate analysis of variance. Conclusion: The collected data show that for the immediate loading of at least four parallel walled transgingival implants stable periimplant parameters can be observed. The success rate of 95.6% for the examined treatment concept is comparable with the findings of delayed loaded implants in this indication. Keywords: immediate loading, bone resorption, success parameter

Objectives: The aim of the present study was to evaluate the influence of different bonding area sizes on tensile bond strength of two different dentin adhesives (Excite, Clearfil New Bond) in vitro. Methods: Eighty freshly extracted third molars were included. All teeth were specially prepared obtaining dentin specimens with a total thickness of 3.5 mm under standardized conditions. The specimens were randomly assigned to eight experimental groups of ten samples each: Group C1: Clearfil (diameter 1 mm), group C2: Clearfil (2 mm), group C3: Clearfil (3 mm), group C4: Clearfil (4 mm); group E1: Excite (1 mm), group E2: Excite (2 mm), group C3: Excite (3 mm), group C4: Excite (4 mm). Tensile bond strength of the above mentioned adhesive agents was measured 15 minutes after application and light curing of the composite material (Tetric Ceram, colour A2) using an universal testing machine. Results: Following tensile bond strengths were evaluated (mean value and standard deviation in MPa): group C1 18.5 (± 10.4), group C2 9.97 (± 3.76), group C3 4.78 (± 2.21) group C4 4.68 (± 2.41), group E1 10.84 (± 6.62), group E2 7.22 (± 3.11), group E3 4.87 (± 1.90) and group E4 3.56 (± 1.11). Statistical analysis showed a significant influence of the used dentin bonding agent and the bonding area size on tensile bond strength (p Conclusions: It can be concluded that different sizes of bonding areas have an influence on tensile bond strength of both dentin adhesive systems tested. The higher bond strength observed in smaller bonding area sizes might explain the known differences between in vitro test and clinical performance of dentin adhesives. Keywords: dentin, dentin bonding agent, tensile bond strength

Objectives: The aim of the present investigation was to evaluate tensile bond strength of a new self-conditioning dentin adhesive system (Xeno III) compared to two established dentin bonding agents (Excite, Syntac) in combination with different composite materials in vitro. Methods: Sixty freshly extracted third molars were included. All teeth were specially prepared allowing the simulation of dentin perfusion. Dentin specimens with a total thickness of 1.5 mm were obtained under standardized conditions. The specimens were randomly assigned to four experimental groups: group A: Xeno III/ Esthet X, group B; Xeno III/ QuiXFil; group C: Excite/ Tetric; group D: Syntac/ Tetric. Tensile bond strength of the above mentioned adhesive agents was measured 15 minutes after application and light curing of the composite material (colour A2) using an universal testing machine. Results: For the four test series following tensile bond strengths were evaluated (mean value and standard deviation in MPa): group A 6.90 (± 1.29), group B 7.48 MPa(± 1.53), group C 4.73 (± 0.87) and group D 3.87 (± 0.54). Statistical analysis showed a significant influence of the used dentin bonding agent on tensile bond strength (p Conclusions: Regarding the limitations of an in vitro study it can be concluded that the self-conditioning dentin adhesive system showed favourable results. Therefore, Xeno III might be a good alternative in clinical practice compared to the other materials tested. Keywords: dentin, dentin bonding agent, bond strength

Objectives: The study was performed to evaluate the influence of dentin perfusion on dentin bond strength of three different dentin adhesives (Excite, Clearfil New Bond and an experimental self-conditioning adhesive) in vitro. Methods: Sixty freshly extracted third molars, stored in saline for a maximum of seven days after extraction were included. All teeth were specially prepared allowing the simulation of dentin perfusion. Dentin specimens with a total thickness of 3.5 mm were obtained under standardized conditions. The specimens were randomly assigned to six experimental groups of ten samples each: Group EM: Excite (moist dentin), group EP; Excite (perfused dentin); group CM: Clearfil (moist dentin), group CP: Clearfil (perfused dentin); group XM: experimental adhesive (moist dentin), group XP: experimental adhesive (perfused dentin). Tensile bond strength of the above mentioned bonding agents was measured 15 minutes after application and light curing of the composite material (Tetric Ceram, colour A2) using an universal testing machine. Results: For the six test series following tensile bond strengths were evaluated (mean value and standard deviation in MPa): group EM 4.09 (± 1.56), group EP 3.92 (± 1.34), group CM 4.68 (± 2.41), group CP 3.18 (± 0.96), group XM 3.14 (± 1.34) and group XP 2.38 (± 0.69). Statistical analysis showed a significant influence of the used dentin bonding agent on tensile bond strength (p Conclusions: The results of this investiation suggest that newer dentin adhesives are not affected by dentin perfusion to the extends described in previous studies. Keywords: dentin, adhesion, bond strength, perfused dentin, dentin bonding agent

Tooth loos and the resulting atrophy of the alveolar crest are causing loos of vertical height. A change in the profile with loos of the lip contour is recognized as sign for an old person.22 edentulous patients were analysed for the soft-tissue profile and phonation before and after implant prosthetic rehabilitation. 6 patients received a fixed reconstruction and 16 patients were treated with a removable bridge in the upper and lower jaw.The orthodontic profile analysis was used to determine the change of the position of the following points: Subnasale, Labrale superior, Labrale inferior, Stomium superior, Stomium inferius, Submentale. As reference points Glabella und Cervicale were used after the determination of the bite.After implant prosthetic rehabilitation in all cases the profile was developed ventral. The minimum and maximum values are shown together with mean value and median. The incorporation of implant-borne superstructure leads to a support of the lip profile for all patients.The reconstruction with fixed superstructure showed a reduced increase of the profile in comparison to the removable bridges. An individual resin base could improve the vestibular contour.The phonation showed better results with the removable superstructures due to less necessary lab adaptations in comparison to the fixed bridges. Keywords: removable fixed implant restoration, profile support, vertical dimension, orthodontic profile analysis

Das Kinnprofil stellt einen bedeutenden Teilaspekt eines harmonischen Gesichtes dar. Die meisten ästhetischen Störungen im Bereich der Kinnregion treten im Zusammenhang mit skelettalen Dysgnathien auf. In der Regel läßt sich heute durch ein kombiniertes orthodontisch-chirurgisches Behandlungskonzept eine zufriedenstellende Verbesserung des Kinnprofiles erreichen. Die Auswertung eines Kollektives von 1564 kombiniert behandelten Dysgnathiepatienten zeigt ein umgekehrt proportionales Verhältnis zwischen der Anzahl von bignathen Umstellungsosteotomien und sekundären Kinnplastiken. Zu Beginn der noch verhältnismäßig jungen Disziplin 'orthopädische Gesichtschirurgie' stand zunächst die Harmonisierung der Kieferbasen im Zentrum der Operationsplanung. Häufig wurde dann eine monognathe Umstellungsosteotomie vorgennommen und sekundär die Kinnregion korregiert. Heute berücksichtigen die modernen Behandlungskonzepte schon primär die Profilpla-nung, was an einem höheren Anteil bignather Umstellungsosteotomien deutlich wird. Erst die komplette Mobilisierung von Ober- und Unterkiefer im Rahmen eines bignathen Eingriffes erlaubt nahezu jede skelettale Position von Ober- und Unterkiefer dreidimensional und gesichtsschädelbezogen einzustellen. Die Neben einer eugnathen Verzahnung läßt sich so, unabhängig von der Ausgangsdysgnathie, nahezu jedes gewünschte Profilbild erzielen. Zusätzliche ästhetische Indikationen zur operativen Kinnkorrektur ergeben sich nur noch selten. Das Ziel der Untersuchung war es, die Indikationen zur zusätzlichen Kinnkorrektur mit Hilfe der FRS-Analyse zu erarbeiten. Keywords: Dysgnathie, orthopädische Gesichtschirurgie, Kinnplastik, Umstellungsosteotomie

Objectives: Former investigations have shown that dentin adhesives and other sealants can prevent root surface caries. The aim of the present study was to determine the caries-protective effect of two different desensitizing agents (Controcar, D/Sense 2) on root surfaces in vitro. Methods: The root surfaces of 30 freshly extracted caries-free human molars were thoroughly cleaned, thereby removing the cementum. The teeth were then coated with acid-resistant nail varnish, exposing two rectangular windows. One window served as an untreated control, while the other window was treated with one of the desensitizing agents. All specimens were distributed among the following experimental groups: A: treated with Controcar; AA: untreated control; B: treated with D/Sense 2; BB: untreated control. All specimens were demineralized for 14 days with acidified gel (HEC, pH 4.8, 37 degrees C). From each tooth, two dentinal slabs were cut. The depth of the demineralized areas was determined using a polarized light microscope. Results: All untreated specimens showed uniform lesions with a mean depth of 81 µm (± 17 µm)in group AA and 77 µm (± 18 µm) in group BB. The specimens treated with Controcar showed a mean lesion depth of 2 µm (± 1.5 µm). In group B, treated with D/Sense 2, a mean lesion depth of 45 µm (± 11 µm) was observed. In both groups (A, B) the lesion depth was reduced significantly compared to the untreated control groups (AA, BB) (p Conclusions: It can be concluded that the demineralization of the root surface can be hampered by the application of desensitizing agents in vitro. Keywords: dentin, demineralization, root caries, desensitizing agent

Objectives: The retention of endodontic posts is believed to be a major factor in restoration survival. The aim of this study was to compare the retentive strength of fibre posts cemented with two different cements in combination with different pre-treatments. Methods: Forty caries free human maxillary incisors were selected for standardized size and quality, endodontically treated and coronally reduced to the cemento-enamel junction. During the experimental period the teeth were stored in saline. All specimens were randomly assigned to four experimental groups of ten samples each. In group A the fibre posts were sand-blasted and cemented with Panavia F. In group B the posts were cemented without sand-blasting. Group C received sand-blasted fibre-posts cemented with Ketac-Cem. In group D the posts were cemented without sand-blasting. Post holes were prepared according to manufacturers' instructions. The fibre posts (Mirafit Carbon) were then cemented with one of the two cements as recommended. Retentive strength was measured 24 hours after cementation using a universal testing machine. Results: The following mean retentive strengths in Newtons for the different groups were: group A: 448.4 N (± 105.9 N); group B: 395.7 N (± 99.9 N); group C: 210.9 N (± 66.5 N); group D: 176.8 N (± 67.2 N). Retentive strength in group A and B (Panavia F) was significantly increased compared to group C and D (Ketac-Cem) (p Conclusions: The reconstruction of endodontically treated single rooted teeth with fibre posts showed acceptable retentive values for all cementation modalities used in this study. The values observed for the composite cement Panavia F were significantly higher compared to the conventional cement Ketac-Cem. Keywords: endodontic posts, retention, fibre posts, luting agents

Prosthetic driven implant placement requires a planning procedure, which considers the available bone and the optimal prosthetic position of the crown. In our days more and more CT-based planning procedures are used, especially for very esthetic demanding cases or if immediate restoration is performed.For the CT-based planning we use routinely a wax-up, which is transferred in acrylic resin. Depending on the esthetic demand of reconstruction two type for the reference are used. For the functional rehabilitation, quite often with immediate loading, the prosthetic axis is referenced by a gutta-percha point ISO 100, which is placed in the center of the crown. For the optimal vertical position the length of the gutta-percha point is chosen in the same length like the cone of the esthetic abutment (FRIADENT, Mannheim, Germany). In esthetic demanding cases the crowns are transferred by a BaSO4-doted resin with is then fixed in a transparent resin. This allows the control of the implant position in relation to the contour of the crown in respect with the soft-tissue situation.Depending to the transfer system for surgery different references are necessary. After the CT-scan the template is modified according the surgical transfer system.Implant planning based on the ideal position of the prosthetic cone of the abutment allows determining the ideal position of the implant under prosthetic considerations. The transfer of the planning by CT-based fabricated template (Med3D, Heidelberg, Germany) or CT-based Navigation (Robodent, Berlin, Germany) is demonstrated. Keywords: static navigation, dynamic navigation, implant planning, 3D imaging

Objectives: Previous studies have shown a correlation between the clinical performance of dentin adhesive systems and the use of flowable composites. The aim of the present study was to evaluate the difference of the tensile bond strength of two different composite/ dentin adhesive combinations depending on the additional use of the corresponding flowable composite. Methods: In this study forty freshly extracted third molars were included. All teeth were prepared in a special manner allowing the simulation of dentin perfusion. The specimens were randomly assigned to four experimental groups of ten samples each: group A: Tetric Ceram combined with Excite; group B: like group A plus Tetric flow; group C: Admira used with Admira Bond; group D: group C plus Admira flow. All materials were applied on a standardized surface area of 2 mm in diameter. Tensile bond strength was evaluated 15 minutes after application using a universal testing machine. Results: For the four test series following tensile bond strength values were evaluated (mean and standard deviation): In group A mean tensile bond strength of 4.74 MPa (plusmn; 1.81) was observed. The additional use of Tetric flow showed bond strength of 10.02 MPa (plusmn; 4.72). In the case of the ormocer Admira tensile bond strength was 3.59 MPa (plusmn; 1.37) and 7.36 MPa (plusmn; 3.91) when Admira flow was additionally applied. Statistical analysis showed a significant influence of the used dentin bonding agents on tensile bond strength in both modifications (p Conclusions: Within the limitations of an in vitro study, it can be concluded that the use of flowable composites might increase tensile bond strength for the used materials. Keywords: dentin, dentin bonding agent, bond strength, composite material

Objectives: The aim of the present study was to evaluate the effect of irradiation on de- and remineralisation of human dentin in vitro. Methods: The root surfaces of 15 freshly extracted caries-free human molars were cleaned, thereby removing the cementum. The teeth were then coated with acid-resistant nail varnish, exposing four rectangular windows. Two windows served as a non-irradiated control, while the other two windows were irradiated. The irradiation dose of 60 Gy was fractionally applied over six weeks (2 Gy/day). All specimens were distributed among the following experimental groups: A: non-irradiated, only demineralisation; AA: non-irradiated, de- and remineralisation; B: irradiated, only demineralisation; BB: irradiated, de- and remineralisation. All specimens were demineralized for 21 days with acidified gel. The remineralisation was performed using a calciumphosphate model for 12 days. From each tooth, two dentinal slabs were cut. The depth of the demineralized areas was determined using a polarized light microscope. Results: In the case of the non-irradiated specimens a mean lesion depth of 205 µm (± 51 µm, group A) after demineralisation and 178 µm (± 32 µm, group AA) after remineralisation was observed. The irradiated specimens showed a mean lesion depth of 195 µm (± 51 µm, group B) after demineralisation and 177 µm (± 42 µm, group BB) after remineralisation. Statistical analysis showed in both cases a significant decrease of the lesion depth after remineralisation (p Conclusion: Within the limitations of an in vitro investigation it can be concluded that irradiation has no effect on de- and remineralisation of human dentin. Keywords: dentin, demineralization, remineralization, caries, irradiation