The SATURN implant by Cortex Dental Industries

Transcription

1 The SATURN implant by Cortex Dental Industries By Dr. Zvi Laster DMD W e P r o v e I t E v e r y D a y

2 A case report using a newly designed implant specifically designed for immediate post-extraction loading Immediate loading may be described as functional loading with occlusal or non-occlusal contacts, immediately after implantation (or early loading 3-14 days after surgery), without waiting for the healing period 1. Immediate loading and early loading has gained popularity with many surgeons over the past decade due to less tissue trauma, reduced overall treatment time, decreased patient discomfort and anxiety, high patient acceptance and superior function and aesthetics 2,3. A crucial factor for successful loading of an implant directly after it has been inserted into the bone is its initial mechanical stability 4 created by friction between the metal and the bone it comes in direct contact with. The primary initial stability in most types of implants designed for immediate loading is achieved by insertion of the implant into a cavity or socket slightly smaller in diameter than the implant s diameter. This initial mechanical stability is reduced over time as the bone adapts to the foreign object, being gradually replaced by biological stability generated through bone osseointegration 5. There is sufficient evidence to suggest that the degree of achieved primary stability during immediate loading protocols is dependent on several factors including bone density and quality, implant shape, design and surface characteristics and surgical techniques 6. Arguments for implant shape and proper techniques are brought forth in this essay. The problem of the loss of initial mechanical stability is intensified in cases of immediate post-extraction loading, due to considerably reduced bone-to-implant contact (BIC). Higher initial (primary) stability is a vital factor in facilitating optimal bone generation, keeping the implant as immobile as possible despite accidental forces which the implant may face. Poor primary stability is one of the major causes of implant failure 7. Other related causes of implant failure include inflammation, bone loss and biomechanical overloading. 2

3 Promoting Primary Stability Through Implant Shape The SATURN implant features a specially designed expanded diameter mid-crestal wing shaped thread. The latter enhances primary stability by providing added bone contact for greater insertion torque. These special enlarged threads, situated 3-4mm below the implant neck, are able to penetrate the compact cortical bone left around the empty socket after the extraction procedure. Implant instability arises due to the fact that when a regular implant is inserted into an empty socket, 50% or more of its surface comes into contact with a blood clot instead of contacting the desired bone. The protruding threads of the SATURN implant compensate for that loss of stability. As a result, this implant is especially useful in esthetic cases where dental extractions are done and implants are placed for immediate provisional loading. Compared to regular shaped implants, the SATURN implant is better suited for immediate loading procedures in the maxilla, especially in posterior positions, since the enhanced initial stability as depicted above is able to compensate for typical lacking bone density and quality in that area (in comparison to the mandible, for example). The SATURN implant is able to create initial insertion resistance of 40N/cm or more without damaging the surrounding bone (over-stressing an implant could lead to necrosis). Finite Element Analysis demonstrates that the added rings considerably reduce stress distribution at the implant neck, thus reducing the potential for bone loss at the crest. Experimental displacement analysis of the implant by a 20 Kg load, angled at 20, led to 40% less maximum implant displacement (8.5 microns with no additional wings versus 5.2 microns). This reduced displacement and better stress distribution at the neck reduces the prospects of bone loss after loading. Von Mlsses Stress [Kg/mm^2] Finite element analysis Circum [deg] The aim of this case report is to introduce an implant with new physical attributes and to highlight its use in an implantation procedure, specifically the immediate loading of an implant inserted into a fresh socket directly after extraction. Implant displacement 5.2 microns Implant displacement 8.5 microns 3

4 R e p o r t o f Pa t i e n t T r e a t m e n t This case report features a female patient, 52 years of age, in good general health, referred for tooth extraction of teeth 11, 21 and 22, who refused a provisional partial denture during temporary bridge assembly. Pre-op panoramic radiograph Intra oral view Alginate impression for first immediate temporary bridge An alginate impression was taken and kept for inspection at later stages of treatment. The teeth were carefully extracted, maintaining the integrity of the surrounding bone. Note that preserving a 360 degrees ring of bone is a key contributing success factor in immediate loading procedures. It is highly recommended to avoid fracturing the very thin layer of buccal cortical bone which may come out with the extracted tooth, possibly leading to several types of complications in cases of immediate loading. Atraumatic extraction of teeth 11, 21, 22 Initial oblique pilot drilling Pilot drilling followed by straight drilling The implant osteotomies can now commence. Because, at this stage, it is crucial to avoid any gliding or sliding over the palatal bevel of the socket, a recommended technique is to start drilling at a right angle to the palatal plane, placing the tip of the drill on the exact spot where we want the osteotomy to be performed. After drilling in 2-3mm, the hand piece is straightened and the drilling is continued to the desired final depth. After the pilot drilling is performed, the remaining drills are used in sequence, achieving the appropriate desired diameter for the chosen implant. It is critical to maintain the integrity of the peri-implant tissues since bone resorption takes place with or without implant placement in the fresh extraction socket8. In this case a SATURN implant was used with a diameter of 3.75mm and a length of 11.5mm. The implant was carefully transported to the empty socket osteotomy using the attached transfer. 4

5 The SATURN Premium package The SATURN is inserted until initial stability is achieved. Then the plastic transfer is removed The Premium implant package by Cortex includes all the necessary parts needed for all types of procedures: An implant, a Premium straight abutment with a plastic transfer attached to an abutment screw, a titanium healing cap, a plastic healing cap, and a surgical cover screw. The plastic healing cap supplied with the package can be used for mounting a temporary crown or for cases where the abutment is left orally and protection is needed for the patient s tongue. This arrangement allows the surgeon to leave the abutment in place while sending a similar abutment along with the impression to the lab. This permits the soft tissue to come in contact with the abutment, allowing for the formation of hemidesmosome-like connections to the titanium, which in turn helps in the prevention of periodontal pockets in the future. Insertion with a straight handle or ratchet through the abutment Torque meter shows more than 40N/cm resistance Plastic transfers are separated from handle and seated on the abutments After carefully delivering the implant from the sterilized capsule using the transfer, the implant is screwed in by hand until basic initial resistance is achieved, sufficient to hold the implant in place while lightly pulling the transfer so as to detach it from the implant. The insertion of the implant into the osteotomy site is continued using a 2.42mm key attached to a straight handle or a ratchet (depending on the implantation location) delivered into the abutment that has the same special opening as the implant itself. The design of the SATURN implant allows for both vertical and horizontal bone compaction as well as featuring a sand blasted acid etched surface. The horizontal bone compaction, or condensing, is created due to an inner conical shape of the implant kernel (implant excluding the threads). The vertical compactionis created through an increasing thread width from tip to neck. This design insures that the entire implant thread has sufficient BIC. Without expanding threads, the threads closer to the neck are subjected to a lesser amount of BIC due to bone erosion by previous thread insertion. By using vertical and horizontal bone compaction it has also been suggested that the primary stability is enhanced due to the creation of an increase in bone density9,10. There is general agreement among implant manufacturers that where poor bone quality and density is apparent around the site, implants with acid-etched surfaces, such as the SATURN, can achieve significantly higher BIC when compared to implants with a machine surface. 5

6 Silicon impression is taken and sent to the laboratory for preparation of reinforced temporarybridge (TB) First TB is trimmed and polished First TB is constructed using the alginate impression First TB is placed with no occlusal contact The pre-attached abutment that comes out of the capsule is not tightly secured to the implant, allowing for easy detachment if necessary. NOTE: in the event of high resistance to detachment, it is recommended that the abutment be removed by the use of the appropriate key, and to complete implant placement to the desired depth using the same size key. The abutment is then reattached and tightened until a resistance of at least 35N/cm is registered. In this case all implants were inserted with over 40N/cm resistance. The plastic transfer/mount that is pre-attached to the abutment in the Premium package consists of two parts, easily separated by hand or tool: A disposable transfer top used for handling, and a slim hollow transfer cap that fits the abutment. After separating the transfers from the handles, they were positioned on the abutments and a silicon impression was taken for the construction of a reinforced temporary bridge. 6

7 First temporary bridge (TB) 5 days after Implantation Reinforced TB made by the laboratory Reinforced second TB replacing the first TB 5 days after implantation The impression taken from the patient was sent to the lab with a duplicate of the type and size of abutments already in place. At that point the alginate impression, that was taken prior to the operation, was used with self-curing acrylic to construct the first temporary bridge, which would function until delivery of the reinforced temporary bridge will be fabricated and delivered by the lab. This first temporary bridge was trimmed into shape and polished appropriately in order to keep the papillae in tact, preserving its natural shape and position. Subsequently, this first temporary bridge was placed in the patient s mouth, preferably with no occlusal contact. In cases of immediate loading, and more so if the immediate loading is performed after extraction, it is vital to pay close attention to any occlusal forces that may be present in the patient s bite. It is highly recommended that implants do not support any occlusal forces or be subjected to lateral forces or movement. It is a good habit to council the patient to use a soft diet and not to bite using the newly installed teeth. Five days after implant placement, the reinforced temporary bridge was installed. Final restoration is cemented 5 months post-op As can be seen, 4 days post implant placement, the gums and papillae had good color and form. The lab-reinforced temporary bridge was shaped specifically to keep the papillae in the same healthy position, pressure free. Some surgeons prefer to cement the second bridge to the adjacent teeth using liquid composite on either side so as to protect the implants from unwanted lateral movement. The final restoration was placed 4 months after implantation. The gum and the shape of the papillae were nominal. A follow-up after 12 months showed no changes in the papillae and there was no evidence of bone recession. 7

8 References: 1. Raghoebar GM, Schoen P, Meijer HJ, Stellingsma K, Vissink A. Early loading of endosseous implants in the augmented maxilla: a 1-year prospective study. Clinical Oral Implants Research 2003;14: Chaushu G, Chaushu S, Tzohar A, Dayan D. Immediate loading of single-tooth implants: immediate versus nonimmediate implantation. A clinical report. International Journal of oral and Maxillofacial Implants 2001; 16: Hui E, Chow J, Li D, Liu J, Wat P, Law H. Immediate provisional for single-tooth implant replacement with Branemark system: preliminary report. Clinical Implant Dentistry and Related Research 2001;3: Rabel A, Kohler SG, Schmidt-Westhausen AM. Clinical study on the primary stability of two dental implant systems with resonance frequency analysis. Clinical Oral Investigations 2007; 11: Natali AN, Carniel EL, Pavan PG. Investigation of viscoelastoplastic response of bone tissue in oral implants press fit process. Journal of biomedical materials research part B applied biomaterials 2009;91: Javed F, Romanos GE. The role of primary stability for successful immediate loading of dental implants. A literature review. Journal of dentistry 38 (2010) p Romanos GE. Surgical and prosthetic concepts for predictable immediate loading of oral implants. Journal of the CaliforniaDental Association 2004;32: Araujo MG, Sukekava F Wennstrom J, Lindhe J. Ridge alterations following implant placement in fresh extraction sockets: an experimental study in the dog. Journal of clinical Periodontology 2005: 32: Summers RB. A new concept in maxillary implant surgery: the osteotome technique. Compendium 1994;15: Summers RB The osteotome technique. Part 2. The ridge expansion osteotomy (REO) procedure. Compendium 1994,15: Veis AA, Papadimitriou S, Trisi P, Tsirlis AT, Parissis NA, Kenealy JN. Osseointegration of Osseotite and machined surfaced titanium implants in membrane-covered critical sized defects: a histologic and histometric study in dogs. Clinical Oral Implants Research 2007; 18: Design & Concept by StudioGE.com AC-IPZVI Rev-01