Implant-Abutment Interface Design on Bone and Soft Tissue Levels Around Implants Placed Using Different Transcrestal Sinus Floor Elevation

Approximately 60 subjects who require at least one posterior maxilla implant in the areas of
the second pre-molars or (first or second) molars with 6 to 9 mm of crestal bone below the
sinus floor, as determined on the computerized axial tomographic (CT) scan, will be recruited
for the study. Subjects will receive dental implants to replace a missing tooth (second
pre-molar or first/second molar) on one side of the maxillary arch. Each subject will receive
one type of implant: platform switched (PS) or platform matching (PM). Each site will receive
either a bone graft material composed of anorganic bovine bone mineralized (ABBM, Bio-Oss,
Geistlich Pharma) or no graft material (collagen membrane used for wound healing (Collatape,
Zimmer)). At implant placement surgery and post-surgical follow-ups, the treated site will be
examined, clinically measured, and radiographs and photographs will be taken.

The central hypothesis is that the mean crestal bone level for the platform switched (test
implants) implants will be superior to the mean crestal bone level for the platform matching
(control implants) implants when placed in limited maxillary residual bone in the posterior
regions, regardless of the use of bone graft material or collagen membrane.

Inclusion Criteria:

1. Subjects must have read, understood and signed an informed consent form.

2. Subjects must be 18 to 70 years of age.

3. Subjects must be able and willing to follow study procedures and instructions.

4. Subject must maintain good oral hygiene.

5. Subjects must have a single tooth missing in the pre-molar or molar region of the
maxilla (ADA tooth positions 2-4 and 13-15; FDI tooth positions 15-17 and 25-27).

6. The mesio-distal distance of the tooth gap at bone level must be at least 6.8 mm to
allow for placement of the Ø3.8 mm implant with a minimal distance of 1.5 mm from the
implant shoulder to the adjacent tooth at bone level. A minimum of 7.8 mm of
buccal-lingual ridge to allow 2 mm of buccal and lingual plate will be required.

7. No apical disorder/inflammation at the area of the implant site.

8. Residual bone height ranging from 6 to 9 mm.

9. The implant must penetrate at least 2 mm into the sinus on the mesial or distal sides.

10. Sufficient bone width in the edentulous region (≥ 6mm).

11. Subjects must be committed to the study and attend the required follow-up visits.

Exclusion Criteria:

1. Subjects with a systemic disease that would preclude dental implant surgery (e.g.
serious internal medical problems, disorders of bone metabolism, uncontrolled bleeding
disorders, weakened immune system, illness requiring periodic use of steroids,
uncontrollable endocrine disorders, uncontrolled diabetes).

2. Subjects who have failed to maintain good plaque control.

3. Subjects with any contraindications for oral surgical procedures (e.g. inadequate
wound healing capacity, poor oral hygiene, maxillary and mandibular growth not
completed, xerostomia).

4. Subjects with mucosal diseases (e.g., erosive lichen planus) in the localized area
around the study implant site.

5. Subjects presenting with maxillary sinus pathology.

6. Subjects with a history of local irradiation therapy in the head/neck region.

7. Subjects with severe bruxing, parafunctional habits, or temporomandibular joint
dysfunction.

8. Subjects receiving, or having a history of receiving intravenous or subcutaneous
antiresorptive agents associated with osteonecrosis of the jaw, such as
bisphosphonates.

9. Oblique sinus floor (> 45 inclination).

10. Subjects with any untreated endodontic lesions or untreated periodontal disease.

11. Subjects who are heavy smokers (defined as >10 cigarettes per day or >1 cigar per day)
or chew tobacco, including within 3 months prior to enrollment.

12. Subjects who have physical or mental handicaps that would interfere with the ability
to perform adequate oral hygiene.

13. Subjects who are pregnant or intending to become pregnant during the duration of the
study.

14. Subjects requiring bone augmentation or socket grafting prior to surgery.

15. Subject allergic to collagen or porcine derived products.

16. Subjects with conditions or circumstances, in the opinion of the investigator, which
would prevent completion of study participation or interfere with analysis of study
results, such as history of non- compliance or unreliability.