OBJECTIVE:This study compared the loosening torque of experimental double conical abutment screws to that of conventional conical abutment screws and flat-head screws in implants with internal connections before and after mechanical loading.MATERIAL AND METHODS:Eighty implant-screw-abutment assemblies were divided into four groups: flat-head screw (Xive S), conical screw (Straumann), conical screw (Nobel Biocare), and double conical screw (RTB). Abutments were tightened to a torque of 30 Ncm. After 10 min, they were retightened and loosening torque was measured. The same abutments were then retightened with new screws to a torque of 30 Ncm and, again, retightened after 10 min. They were then mechanically loaded for 3 000 000 cycles, and loosening torque was again measured. Data were collected, and an exploratory analysis was performed.RESULTS:Comparisons before mechanical cycling showed significant differences between groups. After mechanical cycling, only the comparisons of Straumann and Nobel Biocare showed no significant differences. Considering the same group before and after mechanical cycling, all comparisons showed significant differences.CONCLUSION:The shape of the abutment screw head significantly influenced loosening torque: Double conical-head screws showed significantly higher loosening torque values than conical-head screws. Conical-head screws showed higher loosening torque values than conventional flat-head screws before and after loading.

Ältere pflegebedürftige Personen weisen häufig eine eingeschränkte oder unzureichende Immunabwehr auf. Bei ihnen sind deshalb Mundhygiene und ihre sachgemäße Durchführung besonders wichtig. Dies bereitet aber in Senioren- und Pflegeheimen große Probleme. Welche Möglichkeiten und Grenzen haben Pflegende in Zusammenarbeit mit einem Zahnarzt, Schmerzen zu lindern und eine suffiziente Mundhygiene zu etablieren?

OBJECTIVES Aim of this controlled prospective randomized study was to evaluate the outcome of two-piece zirconia implants compared to titanium implants over a period of up to 24 months. MATERIAL AND METHODS A total of 31 implants (16 zirconia/Ziterion vario Z(®) + 15 titanium/Ziterion vario T(®) ) were inserted primary stable (>30 Ncm) in the maxilla (7) and mandible (24) of 22 patients (13 male, nine female) requiring neither bone nor soft tissue augmentation. After a healing period of 6 months in the maxilla and 4 months in the mandible, ceramic abutments were luted adhesively to the zirconia implants and definitive all-ceramic restoration was performed with high-density ceramics. Radiographic bone levels, condition of the peri-implant mucosa, aesthetic outcome, implant survival and success were recorded for up to 24 months. RESULTS Measurements of mean marginal bone levels 24 months after surgery showed a significant bone loss (P < 0.001) in both groups (Ti: 1.43 (SD ± 0.67) vs. Zir 1.48 (SD ± 1.05). One zirconia implant was lost 8 months after restoration. No further complications were recorded, giving an overall survival and success rate of 93.3% for zirconia and 100% for titanium implants after a period of up to 24 months. CONCLUSIONS After 24 months, success rates of the two-piece ceramic implants showed no significant difference compared to control two-piece titanium implants. The bonded zirconia implant abutment connection appears to be capable with clinical application over the observed period. However, further control measurements need to confirm the presented data.

OBJECTIVE:Aim of this prospective case series was to evaluate the outcome of immediately provisionalized single-piece zirconia implants. MATERIAL AND METHODS:A total of 20 zirconia implants were inserted in single-tooth gaps in the maxilla (11) and mandible (9) of 20 patients. Implants were restored with all-ceramic CAD/CAM provisionals without occlusal contacts immediately after placement. Permanent all-ceramic restoration was performed 4 months after surgery. Plaque index (PI), bleeding on probing (BOP), Periotest(®) (PV), pink aesthetic score (PES), mean radiographic marginal bone levels (MBL), implant survival and success were evaluated up to 24 months. RESULTS:Assessment of PI at baseline and follow-ups after 6, 12, 18 and 24 months revealed 27% (±5.3), 24% (±6), 23% (±6.1), 23% (±5.3) and 22% (±6.4), respectively. Evaluation of BOP revealed 25% (±5.6), 21% (±6), 21% (±7.2), 18% (±5.9) and 15% (±5.5), respectively. Implants presented stable at follow-ups (PV). PES improved, but not statistically significant from 8.13 (±1.5) at baseline to 10 (±2) 24 months after implantation. Measurements of MBL showed a significant bone loss of 1.01 mm within the first year after placement (P < 0.001) and 1.29 mm 24 months post-implant insertion, not reaching further statistically significant levels (P > 0.05). One implant was lost 4 months after placement, resulting in a survival and success rate of 95%. CONCLUSION:Clinical and radiographic parameters demonstrated a 95% integration of immediately loaded zirconia single-piece implants. A long-term randomized-controlled clinical trial was initiated to confirm evidence of this protocol.

Die in den vergangenen Jahren rasch fortgeschrittenen Entwicklungen auf dem Gebiet der vollkeramischen Werkstoffe lassen es sinnvoll erscheinen, die bestehenden Präparationsrichtlinien dahingehend zu überdenken: Inwieweit vermögen diese den doch deutlich unterschiedlichen Materialeigenschaften von Keramik zu entsprechen? Im Gegensatz zu metallischen Materialien ist Keramik ein hochgradig sprödes Material, welches keinerlei Fähigkeit zur plastischen Verformung im Mund aufweist (Abb. 1) (Arnetzl et al. 2007). Deshalb ist es angebracht, die Kavitätengeometrie auf die werkstoffspezifischen Eigenschaften von Dentalkeramiken abzustimmen.

Amelogenesis imperfecta (AI) bezeichnet genetisch bedingte Dysplasien des Schmelzes. Infolge verschiedener Defekte wird quantitativ und/oder qualitativ abnormer Schmelz gebildet, während die Dentinstruktur normal ist. Der vorliegende Beitrag beschreibt die Erkrankung und stellt den Fall eines vierjährigen Mädchens vor.

Pulver-Wasserstrahlgeräte werden heutzutage vor allem im Rahmen der Dentalhygiene und der Parodontaltherapie eingesetzt. In der Literatur belegen Untersuchungen, dass diese Substanzdefekte verursachen können. Die vorliegende in vitro Pilotstudie untersucht die Auswirkungen dieser Behandlungsart auf verschiedene Keramiken. Diese Keramikoberflächen wurden zum einen hochglanzpoliert und zum anderen mit einem Glanzbrand versehen. Danach wurden sie mit einem Pulver-Wasserstrahlgerät behandelt und auf eventuelle Substanzdefekte hin untersucht. Die Defekttiefen wurden gemessen und mit den unbehandelten Keramikoberflächen verglichen. Es zeigte sich bei allen mit dem Pulver-Wasserstrahlgerät behandelten Keramikoberflächen ein Substanzabtrag im Bereich von 0,711 µm bis 1,265 µm. Durch diese Ergebnisse ist eindeutig bewiesen, dass pulverstrahlbehandelte Keramikoberflächen Substanzdefekte aufweisen.

Objective:To investigate the oral state in participants cared for in residences for senior citizens in Styria, Austria.Materials and methods:Four hundred and nine participants in Styria from nine homes for senior citizens were examined employing parameters in accordance with those of Folstein's Mini Mental Status (MMS), DMFT, basic periodontal examination, the modified oral hygiene index, pain experienced during the preceding year, the subjective and objective need for treatment, and also requirements involving surgical and prosthetic treatment. Furthermore, the habitual methods of maintaining oral hygiene were examined establishing by whom this was carried out - whether by the patient, the nurse, or by patient and nurse together.Results:Four hundred and nine participants were examined, 48.3% were found to have retained on average 4.9 of their own teeth while 69% were fitted with dentures; however, 81% of the participants required prosthetic treatment. 28.9% of the participants had experienced acute dental pain during the preceding year and surgical treatment was found to be necessary in 47.7% of those with original teeth. Eighty-four per cent of the participants showed acute inflammation of the periodontium while the state of oral hygiene, measured on a scale of 0-4, reached an average of 2.43. Oral hygiene was carried out by the nurses in only 7.46% of the cases which showed an average MMS measurement of 18.Conclusion:The results compared with those reported in other recent surveys and our data show an urgent need in Austria to improve the standards in dental care for the hospitalised elderly. Regular dental checks, carried out in the actual home by a dental surgeon should be introduced, whilst the nursing staff should be made fully aware of the problems caused by insufficient oral care and receive regular support from specialised oral hygiene assistants. The results of this survey also suggest that nursing staff should be equipped with simple instruments in order to judge to the extent to which the patient is capable of carrying out oral care independently and then according to the results to supplement this with additional care.