 Astra Tech
BioManagement Complex
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 Connective Contour
Connective Contour" is the unique and scientifically documented contour that increases soft tissue contact zone and volume, created when the abutment is connected to the implant. Connective Contour is also an original key feature of the Astra Tech Implant System™.
The summaries in this section highlight the understanding of soft tissue healing around and esthetics maintained by the Astra Tech Implant System.
 Astra Tech single-tooth implants: an audit of patient satisfaction and soft tissue form
Purpose: One area that influences the patient satisfaction scores for implant treatment is the interdental papilla form and the factors that determine its presence, absence or degree of fullness. Different studies have reported differing methodology but in general the results would indicate that implants are less capable of retaining a full papilla compared to natural teeth.
This study set out to determine patient satisfaction levels with single-tooth implants and to compare these scores to a rating by the clinician in light of papilla fill and marginal bone levels, as well as to consider the relationship between the two.
Materials and Methods: Sixty-six patients treated for single-tooth replacement in the anterior maxilla were enrolled to the study. All implants had been in function for a minimum of 12 months. Patient questionnaires were completed as part of their recall program with a scale of 1 to 6 to score each parameter from extreme dissatisfaction to total satisfaction. Parameters included crown form and color, masticatory and phonetic function, comfort, and ease of care. In addition, 4-site pocket depths were recorded along with a score for the papilla fill (Jemt index) where 0 = no papilla to 4 = papillary hyperplasia.
Intra-oral radiographs were taken using a Rinn device for standardization. In order to identify contact points (CP), fine orthodontic wire was tightened around each contact to allow accurate measurements of both vertical and horizontal distances taken from the first bone-to-implant contact to the contact point fBIC-CP, the peak of periodontally sound bone adja-cent to the natural tooth to the contact point, pBNT-CP, implant shoulder (IS) to fBIC as well as the hori-zontal distance from the shoulder of the implant to the adjacent tooth, (HD). Results were subject to both paired and two-group t-tests as well as the Mann-Whitney-U test.
Results: Sixty-six patients all scored their crowns as a 6 for color and form compared to a score of 4.5 - 5.5 as scored by the clinicians, (p < 0.001). With respect to function all patients again scored 6. Twenty crowns were devoid of contact points thereby excluding them from the radiographic analysis, but all these crowns were associated with normal looking papillae. For the other 46 crowns almost 50% of papillae received a score of 2 and 50% received a score of 3 (ideal). No papilla scored 0 or 4. Probing revealed mean pocket depths of 2.63 mm at implants compared to 2.09 mm at teeth, (p < 0.001).
Radiographic analysis revealed that the mean of the mesial and distal median distances for fBIC-CP measured 9.3 mm for a papilla score of 2 and 7.7 mm for a papilla score of 3. The average distance for pBNT-CP measured 6.58 mm for a papilla score of 2 and 5.26 mm for a score of 3. HD measured 2.6 mm for a papilla score of 2 and 1.85 mm for a score of 3. The distance IS-fBIC measured 0.0 mm in most cir-cumstances as bone was at the reference level. The differences between values for papillae with a score of 2 and 3 were highly significant on the mesial side only, (tooth p < 0.001; implant p = 0.002). There was a highly significant difference between distances of IS-CP in favor of the distal surface of implants which gave the impression that radiographic distance for bone levels was better on the distal side.
Discussion and Conclusion: The current study provides conclusive evidence that there is a high chance of fulfilling patient's expectations with a single-tooth implant, with patient satisfaction scoring consistently higher than the clinicians. This corroborates previous studies.
With respect to papilla fill as it relates to peak bone levels, previous studies have lacked clarity, with techniques such as bone sounding yielding imprecise data. This study utilized a novel technique for imaging the contact point so that accurate and reproducible measurements could be made radiographically.
These data reveal a similar trend to that already proposed but with slightly different numbers. In the current study a papilla score of 3 (ideal) could be achieved when the critical CP- pBNT distance measured 6 mm for teeth, or when the CP- fBIC measured 8.5 mm for implants, at the 95% confidence interval. These values are greater than those proposed by Tarnow et al, whose 5 mm rule is universally adopted, where some loss of papilla would be expected at 6 mm. In addition no influence was found on the horizontal distance between teeth and implants, with bone being retained at the implant reference level in almost all sites. This may be related to implant design.
The finding that distal values were smaller was significant and this may be due to a more apically located contact point as has previously been proposed. This was confirmed through radiographic measurements of the distance IS - CP, which indi-cated that the distal CP was typically 1.5 mm more apical than the mesial CP. This may have an impact on papilla form although there was no significant discernable difference between mesial and distal papilla fill in the current study.
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