Small-diameter titanium grade IV and titanium-zirconium implants in edentulous mandibles: five-year results from a double-blind, randomized controlled trial.

BACKGROUND The aim of this study was to compare the 5-year survival and success rates of 3.3 mm dental implants either made from titanium-zirconium (TiZr) alloy or from Grade IV titanium (Ti Grade IV) in mandibular implant-based removable overdentures. METHODS The core study had a follow-up period of 36 months and was designed as a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann Bone Level implants (diameter 3.3 mm, SLActive®), one of TiZr (test) and one of Ti Grade IV (control), in the interforaminal region. This follow-up study recruited patients from the core study and evaluated the plaque and sulcus bleeding indices, radiographic crestal bone level, as well as implant survival and success 60 months after implant placement. RESULTS Of the 91 patients who initially received implants, 75 completed the 36 month follow-up and 49 were available for the 60 month examination. Two patients were excluded so that a total of 47 patients with an average age of 72 ± 8 years were analysed. The characteristics and 36-month performance of the present study cohort did not differ from the non-included initial participants (p > 0.05). In the period since the 36-month follow-up examination, no implant was lost. The cumulative implant survival rate was 98.9 % for the TiZr group and 97.8 % for the Ti Grade IV group. Crestal bone level changes at 60 months were not different in the test and control group (TiZr -0.60 ± 0.69 mm and Ti Grade IV -0.61 ± 0.83 mm; p = 0.96). The cumulative implant success rate after 60 months was 95.8 and 92.6 % for TiZr and Ti Grade IV, respectively. CONCLUSIONS After 60 months, the positive outcomes of the 36 month results for TiZr and Ti Grade IV implants were confirmed, with no significant differences with regard to crestal bone level change, clinical parameters and survival or success rates. TiZr implants performed equally well compared to conventional Ti Grade IV 3.3 mm diameter-reduced implants for mandibular removable overdentures. TRIAL REGISTRATION Registered on www.clinicaltrials.gov: NCT01878331.

Small-diameter titanium Grade IV and titanium-zirconium implants in edentulous mandibles: three-year results from a double-blind, randomized controlled trial

OBJECTIVE The aim of this study was to compare crestal bone-level changes, soft tissue parameters and implant success and survival between small-diameter implants made of titanium/zirconium (TiZr) alloy or of Grade IV titanium (Ti) in edentulous mandibles restored with removable overdentures. MATERIALS AND METHODS This was a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann bone-level implants (diameter 3.3 mm), one of Ti Grade IV (control) and one of TiZr (test), in the interforaminal region. Implants were loaded after 6-8 weeks and removable Locator-retained overdentures were placed within 2 weeks of loading. Modified plaque and sulcus bleeding indices, radiographic bone level, and implant survival and success were evaluated up to 36 months. RESULTS Of 91 treated patients, 75 completed the three-year follow-up. Three implants were lost (two control and one test implant). The survival rates were 98.7% and 97.3%, and the mean marginal bone level change was -0.78 ± 0.75 and -0.60 ± 0.71 mm for TiZr and Ti Grade IV implants. Most patients had a plaque score of 0 or 1 (54% for test and 51.7% for control), and a sulcus bleeding score of 0 (46.1% for test and 44.9% for control). No significant differences were found between the two implant types for bone-level change, soft tissue parameters, survival and success. CONCLUSIONS After 36 months, similar outcomes were found between Ti Grade IV and TiZr implants. The results confirm that the results seen at 12 months continue over time.

The Perceived Prognosis of Endodontic Treatment and Implant Therapy Among Dental Practitioners

Little data concerning the perceived success of implant therapy in comparison with endodontic treatment exists. While the criteria used to measure the outcome of each modality are not the same, it is not clear if this is appreciated by practicing dentists. The purpose of the study was to evaluate the perceived outcome of implant therapy in comparison to endodontic treatment. A 23 question Web-based survey was distributed to 648 dentists who matriculated from the University of Connecticut School Of Dental Medicine over the past 30 years. The response rate was 47%. Sixty-seven percent of respondents were general dentists. Forty-nine percent of respondents did not know different criteria exist in the literature and are used to evaluate implant and root canal treatment. Fifty-four percent of dentists felt the prognosis of implant therapy was the same as or better than endodontic treatment of teeth with vital pulps. Thirty percent of responders thought root canal treatment of teeth with necrotic pulp was superior to implants and only 16% thought retreatment was preferable. Treatment planning for implant placement vs. retreatment of a restorable tooth was 46% and 32%, respectively. A third of the respondents felt that the role of endodontics will decline in the future. Dentists’ primary source of information regarding implant therapy was continuing education; however, their primary source of information regarding endodontic treatment was their dental program. Dentists felt the prognosis of implant therapy was as good or superior to endodontic treatment of teeth with vital, necrotic or previously treated pulps.

Asymmetric Information, Tax Evasion and Alternative Instruments of Government Revenue

Using a pure-exchange overlapping generations model, characterized with tax evasion and information asymmetry between the government (the social planner) and the financial intermediaries, we try and seek for the optimal tax and seigniorage plans, derived from the welfare maximizing objective of the social planner. We show that irrespective of whether the economy is characterized by tax evasion, or asymmetric information, a benevolent social planner, maximizing welfare and simultaneously financing the budget constraint, should optimally rely on explicit rather than implicit taxation.

The Wave Equation for Stringed Instruments

An elementary derivation of the wave equation as applied to violin strings is given.

Société des Instruments Anciens de Paris

Signatur des Originals: S 36/F07786

Cary's Illustrated and Priced Catalogue: Surgical Instruments, Physicians, Hospital Supplies, and Furnishings, Druggist Sundries, Etc.

Second Edition. Pp.5-61 General Surgical Necessities, Gauze, Antiseptic Sundries, Surgical Sundries, Rubber Bandages, Catheters, Bougies, Splints, Tents, Emergency Bags, Surgeon's Needles, Operating Instruments, Amputating, Forceps, Aspiration, Cases, Catheters and Directors, Pocket Case Instruments, Dissecting and Post-Mortem Pp.62-118 General Operating - Osteotomy, Mastoid, Trephining, Eye Instruments, Aural, Nasal, Mouth and Throat, Tooth Forceps, Laryngoscopic Sets, Hydraulic Air Compressor, Variocele, Genito Urinary Pp. 119-167 Genito Urinary-Lithotrity, Alimentary, Anal and Rectal, Gynaecological, Pessaries, Microscopes, Syringes Pp.168-205 Chemical Apparatus and Glassware, Physician's Cabinets, Office Furniture, Operating Chairs and Tables, Hospital Beds, Cautery, Electrolytic, Batteries Pp.206-246 Cases, Varicose, Braces, Abdominal Supporters, Trusses, Invalid Chairs and Supplies, Sterilizers, Saddle-Bags, Deformity Apparatus Advertisements: Bandages, Abdominal Supporters, Rubber Supplies, Bags, Batteries, Cotton, Microscopes, Hypodermic Tablets, Atomizers, Furniture, Sterilizers, Syringes

Illustrated Catalogue of Standard Surgical Instruments and Allied Lines

Section "A": Dissecting and Post-Mortem Instruments Diagnostic Instruments and Apparatus Microscopes and Microscopic Accessories Laboratory Apparatus and Glass Ware Apparatus for Blood and Urine Analysis Apparatus for Phlebotomy, Cupping and Leeching Apparatus for Infusion and Transfusion Syringes for Aspiration and Injection Osteological Preparations Section "B": Anaesthetic, General Operating, Osteotomy, Trepanning, Bullet, Pocket Case, Cautery, Ligatures, Sutures, Dressings, Etc. Section "B" continued Section "C": Eye, Ear, Nasal, Dermal, Oral, Tonsil, Tracheal, Laryngeal,Esophageal, Stomach, Intestinal, Gall Bladder Section "C": continued Section "D": Rectal, Phimosis, Prostatic, Vesical, Urethral, Ureteral, Instruments Section "E": Gynecic, Hysterectomy, Obstetrical, Instrument Satchels, Medicine Cases Section "F": Electric Cautery Transformers, Electro-Cautery Burners and Accessories, Electric Current Controllers, Electro-Diagnostic Outfits, Electrolysis Instruments Electro-Therapeutic Lamps, Faradic Batteries, Galvanic Batteries Section "G": Office Furniture, Office Sterilizing Apparatus, Hospital Supplies, Surgical Rubber Goods, Sick Room Utensils, Invalid Rolling Chairs, Invalid Supplies Section "H": Artificial Limbs, Deformity Apparatus, Fracture Apparatus, Splints, Splint Material, Elastic Hosiery, Abdominal Supporters, Crutches, Trusses, Suspensories, Etc. Index