Unique challenges posed by the atrophic posterior maxilla often require hard tissue augmentation either before or in conjunction with implant placement, if an implant supported prosthesis is the final treatment goal. Buccolingual and apico-occlusal resorption patterns, in combination with sinus pneumatization, mandate three-dimensional conceptualization and an appropriate regenerative approach. 1
Sinus augmentation therapy, with or without autogenous bone grafting, has been demonstrated to significantly increase the apico-occlusal bone volume of the atrophic posterior maxilla. Unfortunately, the temporal and financial commitments inherent in such a therapeutic approach often pose significant obstacles to acceptance of therapy by the patient. 2–6
In an effort to shorten the course of therapy and lessen the financial challenge to the patient, Summers detailed the use of osteotomes to perform localized sinus augmentation therapy. 7,8 A modification of this technique, in combination with trephines, has been described for use at the time of maxillary molar extraction. 9
The use of osteotomes to apically displace the floor of the sinus, generally begins in one of two manners. Either the narrowest osteotome is used to compress bone, lift the floor, and create an initial path of access for the use of subsequent wider osteotomes, or a 2-mm twist drill is first used to approach the floor of the sinus and prepare a channel for the use of osteotomes, when a significant amount of residual alveolar bone remains coronal to the floor of the sinus. If osteotomes are used without first preparing a channel in the bone with a bur, a significant amount of force must be applied to compress the residual alveolar bone. Such force application and repeated malleting may be disconcerting to the patient. However, if a 2-mm twist drill is first used to lessen the trauma to the patient, alveolar bone is prepared and removed from the site, which might otherwise be imploded when the floor of the sinus is lifted.
A technique that would lessen trauma to the patient, conserve the maximum amount of alveolar bone at the precise site of anticipated implant placement, and limit the incidence of sinus membrane perforation would offer clinical benefits. Herein are the rationale and subsequent protocol.
Materials and Methods
After a thorough review of medical histories, patients were deemed unsuitable to receive augmentation therapy based upon the following criteria: (1) the presence of uncontrolled diabetes, an immune disease, or other contraindicating systemic conditions; (2) radiation therapy to the head and neck region in the 12 months before proposed therapy; (3) chemotherapy in the 12-month period before proposed therapy; (4) uncontrolled periodontal disease, or an unwillingness to undergo needed periodontal therapy, around remaining teeth; (5) an active sinus infection, or a history of persistent sinus infections; (6) a smoking habit of one package of cigarettes per day or greater; (7) a psychological problem, such as depression or anxiety, which would render the delivery of comprehensive therapy untenable and would prevent the patient from undergoing numerous, lengthy treatments; and (8) an unwillingness to commit to a long-term, posttherapy maintenance program.
A complete examination of oral hard and soft tissues was carried out for each patient, and an overall treatment plan was formulated in conjunction with the treating restorative dentists. Panoramic radiographs were taken of all patients by a certified dental assistant. Diagnostic casts, face-bow mountings on articulators, diagnostic wax-ups, and surgical templates were also used (as deemed necessary). Seventy-one sites in 61 patients were treated. Of these patients, 35 were female (57%) and 26 were male (43%). Patient age ranged from 46 to 79 years. The author performed all surgical therapy and preoperative and postoperative measurements.
A midcrestal incision was carried out at the anticipated site of implant placement. The mesiobuccal, distobuccal, mesiopalatal, and distopalatal aspects of the crestal incision were connected to four vertical releasing incisions. Buccal and palatal mucoperiosteal flaps were reflected in a full thickness manner.
A calibrated trephine bur (Ace Surgical Supply, Brockton, MA) of the largest external diameter possible, without compromising the buccal and palatal line angles of the residual alveolar ridge, was placed at the site of anticipated augmentation and subsequent implant placement. Using preoperative radiographs and a residual ridge morphology as a guide, the trephine was employed to prepare the site to within 1–2 mm of the sinus membrane at a maximum cutting speed of 500 rpm. After removal of the trephine bur, if the alveolar bone core was found to be inside the trephine, the core was gently removed and replaced in the osteotomy site. Such an occurrence was noted in two sites.
A calibrated, offset osteotome (BioHorizons Implant Systems, Inc., Birmingham, AL) was selected to correspond to the diameter of the trephine preparation. The osteotome was used under gentle malleting forces, to implode the trephine bone core to a depth approximately 1 mm less than that of the prepared site. Such measurements were possible due to the calibration of both the trephine and the osteotome.
The osteotomy site was gently packed with Bio-Oss (Geistlich, Inc., Bern, Switzerland) and covered with a BioGuide membrane (Osteohealth Company, Shirley, NY), which was secured with fixation tacks. The mucoperiosteal flaps were replaced and sutured with Gore sutures (W.L. Gore & Co., Flagstaff, AZ) to effect passive primary flap closure (Figs. 1–6).
Sites were re-entered approximately 4 to 5 months postoperatively and implants were placed. Full thickness buccal and palatal mucoperiosteal flaps were reflected in 41 cases before implant placement. Ten sites were treated without a reflected flap. In these sites, a circle of soft tissue was removed from the alveolar crest with a scalpel and curette at the anticipated site of implant placement.
Implant placement was accomplished in 49 of the 51 sites in the following manner:
- A 2.2-mm twist drill was used at a speed of 500 rpm to a depth within 1–2 mm of the sinus membrane.
- Offset osteotomes were used to widen the osteotomy site and compress the surrounding bone to a width of 3.5 or 4.0 mm, depending upon whether an implant with a final diameter of 4.1 or 4.8 mm, respectively, was to be placed.
- The appropriate tap was used in the osteotomy site 30 rpm for two revolutions.
- The ITI implant (Straumann and Co., Waltham, MA) was placed at 30 rpm.
- Two implants were placed through use of an osteotome and a trephine to implode an additional core of alveolar bone, lifting the sinus membrane 2 to 3 mm before implant insertion as described above. The implants were then inserted.
- Titanium healing caps were placed and the soft tissues were sculpted and sutured around the necks of the implants, so that the implants were placed in a non-submerged manner. Interrupted Gore-Tex sutures were used to attain passive primary soft tissue closure.
- All implants had solid abutments placed at 35 Ncm, 6 to 12 weeks postoperatively. The implants were temporized at the time of abutment placement. Different restorative dentists accomplished these temporizations.
Post Operative Management
Medications prescribed postoperatively included Peridex rinses twice a day for 21 days, amoxicillin 500 × 40, 4 times daily (enteric-coated erythromycin 400 × 30, 3 times daily was used in penicillin-sensitive patients), Lodine (Etodolac) 400 × 15, 3 times daily unless medically contraindicated, and pain medication (Tylenol with Codeine III or Percocet) as needed.
Patients were not allowed to use removable prostheses over the surgical sites until after the sutures were removed 10 to 12 days postoperatively. At that time, removable prostheses were adjusted, relined, and placed for cosmetic purposes only. Patients were not allowed to function with these removable appliances throughout the healing of the regenerating tissues.
Assessment of Success
The implants were deemed successful if they fulfilled Albrektsson et al criteria under function. 10 All implants were restored and were successful in function at the time of statistical compilation.
Osteotome and trephine sinus augmentation was accomplished in 71 sites. Of the 71 sites, 51 have had implants placed and restored at the time of statistical compilation. Two of these implant placements necessitated additional augmentation through the use of the trephine and osteotome technique at the time of implant placement. All 51 implants were restored and functioning successfully when evaluated by the Albrektsson criteria (Figs. 7 and 8).
Summers introduced the bone-added osteotome sinus floor elevation procedure in 1994 in an effort to simplify the augmentation that is often mandated in the atrophic posterior maxilla in anticipation of implant prosthetic reconstruction. 7,8 Although such a therapeutic approach may not be indicated in the presence of significant buccolingual bone atrophy, because of the need for buccolingual hard tissue ridge augmentation to effect ideal implant positioning, there is no doubt that the bone added osteotome sinus floor elevation procedure has greatly simplified augmentation of the posterior maxilla in a variety of clinical situations.
The technique presented offers a number of advantages. When 4 to 5 mm of alveolar bone remains coronal to the floor of the sinus, the use of a trephine and osteotome is less traumatic and disconcerting to the patient than repeated malleting in an attempt to compact 4 to 5 mm of bone and lift the floor of the sinus with the initial osteotome entry. Although some practitioners have suggested the use of a 2-mm twist drill to prepare a channel for the initial osteotome, thus eliminating the need for extensive malleting, such an approach has the disadvantage of removing a significant amount of alveolar bone from the site.
It should be noted that the extent of apical positioning of the imploded alveolar core, and the subsequent sinus augmentation, is limited by the amount of residual alveolar bone coronal to the sinus at the initiation of the procedure. The core is only imploded to a depth 1 mm less than the depth of the trephine preparation, in an effort to ensure that the core remains held in place by surrounding residual alveolar bone and contained beneath an intact sinus membrane. Such an approach helps to minimize the chances of sinus perforation and unpredictable core displacement.
If a longer implant is desired compared with the implant placed in the subsequently augmented sinus, the osteotome and trephine technique is once again used to implode the floor of the sinus at the anticipated site of implant placement, thus attaining further apico-occlusal dimension for simultaneous implant placement. The technique for placement of the implant at the time of this secondary sinus augmentation, through the use of the trephine and osteotome technique, has already been described. 11
The use of a combined trephine and osteotome technique allows the relatively atraumatic implosion of an autogenous alveolar bone core in a controlled manner and the apical displacement of the floor of the sinus, while minimizing the risk of sinus membrane perforation. This technique offers a number of advantages over the traditional bone added osteotome sinus floor elevation procedure.
1. Bahat O, Fontesi RV, Preston J. Reconstruction of the hard and soft tissues for optimal placement of osseous integrated implants
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Abstract Translations [German, Spanish, Portuguese, Japanese]
AUTOREN: Paul A. Fugazzotto, D.D.S., P.C.** privat praktizierender Arzt. Schrifverkehr: Paul A. Fugazzotto, D.D.S., P.C., 25 High Street, Milton, MA 02186. Telefon: 617 696 7257
ZUSAMMENFASSUNG: Die hier vorgestellte Technik nutzt zur Implosion des Kerns des hinteren Oberkieferalveolarknochens Schädelbohrer verschiedenen Durchmessers und Kiefermeißel, bevor zur Vorbereitung der Implantation regeneratives Material in die Höhle eingebracht wird. Innerhalb dieser Studie wird eine mathematische Formel vorgestellt, die die Tiefe der Kernimplosion mit der Spitzenokklusalausdehnung des Alveolarknochenkranzes zum Sinusboden bereits vor Erfolgen des Eingriffs in Relation setzt. Bei der Untersuchung von 71 Implantaten konnte bei allen ein für die Implantierung ausreichender Wiederaufbau der Knochensubstanz beobachtet werden. Nur bei zwei der untersuchten Objekte waren zusätzliche Verstärkungsmaßnahmen zur Implantation notwendig. 59 der wiederhergestellten Implantate konnten bis zu 3 Jahre lang im Einsatz bleiben. Bei allen Implantaten ist gemäß der Albrektson-Kriterien volle Funktionstüchtigkeit gegeben. Die Abhandlung umfasst detaillierte Informationen zu technischem Vorgehen und Indikationen bzw. Gegenanzeigen.
SCHLÜSSELWÖRTER: Sinusaufbau, Knochenmeißel, unterstützter Knochenwiederaufbau, Implantate
AUTOR: Paul A. Fugazzottto, D.D.S., P.C.* *Práctica Privada. Correspondencia a: Paul A. Fugazzotto, D.D.S., P.C., 25 High Street, Milton, MA 02186. Teléfono: 617 696 7257
ABSTRACTO: Se presenta una técnica que utiliza trépanos de varios diámetros externos seguidos por un osteótomo para implosionar el núcleo de un hueso maxilar posterior alveolar antes de la colocación de materiales de restauración como anticipación de la colocación posterior de un implante. Se presenta una fórmula matemática, que se relaciona con la profundidad de la implosión del núcleo hasta la dimensión apico oclusal del hueso alveolar coronal al piso del seno prequirúrgico. Se han tratado setenta y un sitios. Todos los implantes exhibieron una regeneración suficiente para la colocación de un implante. Dos de los sitios necesitaron un aumento adicional en el momento de la colocación del implante. Cincuenta y nueve de los implantes han sido restaurados y están en funcionamiento durante hasta 3 años. Todos funcionan exitosamente, como lo define el criterio de Albrektson. La técnica y sus indicaciones y contraindicaciones se describen en detalle.
PALABRAS CLAVES: aumento del seno, osteótomo, trépano, regeneración guiada del hueso, implantes
AUTOR: Paul A. Fugazzotto, D.D.S., P.C.* *Clínica particular. Correspondências devem ser enviadas a: Paul A. Fugazzotto, D.D.S., P.C., 25 High Street, Milton, MA 02186. Telefone: 617 696 7257
SINOPSE: é apresentada uma técnica que utiliza trépanos de diversos diâmetros externos seguidos de um osteótomo para implodir uma base de osso alveolar posterior maxilar para a colocação de materiais de regeneração antes da colocação subseqüente de implantes. Uma fórmula matemática, que relaciona a profundidade da implosão da base com a dimensão de oclusão apico do osso alveolar coronal e com o fundo do antro antes da cirurgia, é apresentada. Setenta e um locais foram tratados. Todos os implantes exibiram regeneração suficiente para a colocação dos implantes. Dois locais necessitaram de ampliação adicional na ocasião da colocação do implante. Entre os implantes, cinqüenta e nove foram restaurados e têm sido utilizados por até 3 anos. Todos estão sendo utilizados com sucesso, conforme estabelecido pelo critério Albrektson. A técnica e suas indicações e contra-indicações são descritas em detalhes.
PALAVRAS-CHAVES: ampliação do antro, osteótomo, trépano, regeneração dirigida doosso, implantes