Implantology Posts

12/10/15
Rehabilitation of maxillary edentulism by means of computer-guided implant surgery and provisional prosthesis with immediate loading
Fabio Cozzolino Roberto Sorrentino Luigi De Stefano

07/11/13
Controlled Split Crest and Guided Bone Regeneration (GBR) with contemporary implant placement: rationale and limits of the clinical application in esthetic areas.
Fabio Cozzolino Dario Mari Roberto Sorrentino

24/04/13
Straumann implant guided-surgery with Codiagnostix Software and immediately-loaded prosthesis
Fabio Cozzolino Roberto Sorrentino Vincenzo Mutone

16/10/12
The Membragel Straumann liquid membrane
Fabio Cozzolino

28/09/12
Mandibular full-arch restoration with Straumann implant-supported metal mesostructures and zirconia-based prosthesis: a case report
Roberto Sorrentino Fabio Cozzolino

09/06/09
Implant positioning in the Esthetic zone
Giuseppe Cozzolino Fabio Cozzolino

14/05/09
Mini maxillary sinus elevation using Sincrest
Fabio Cozzolino Giuseppe Cozzolino

23/04/09
Sonosurgery Komet sonic tips
Ivo Agabiti

15/02/09
Controlled bone expansion
Fabio Cozzolino Giuseppe Cozzolino Anna Mariniello

27/12/08
Straumann implant with bone regeneration (GBR) by using Bio-Gide And Bio–Oss
Fabio Cozzolino Giuseppe Cozzolino Anna Mariniello

11/12/08
Bone Level Straumann implants
Fabio Cozzolino Giuseppe Cozzolino Anna Mariniello

08/11/08
Rehabilitation of complete mandibular edentulism by means of an implant-supported overdenture retained by the Locator® System
Fabio Cozzolino Carlo Montesarchio

31/10/08
Delayed loading of post-extractive Straumann implants inserted in maxillary molar area
Fabio Cozzolino Giuseppe Cozzolino Vincenzo Mutone


Rehabilitation of maxillary edentulism by means of computer-guided implant surgery and provisional prosthesis with immediate loading

Rehabilitation of maxillary edentulism by means of computer-guided implant surgery and provisional prosthesis with immediate loading

Computer-guided implantology and immediate loading with CAD-CAM screw-retained full-arch temporary prosthesis

 

A 41 year-old female patient presented with multiple missing teeth at both dental arches and a few remaining elements, among which fractured and non vital teeth. Moreover, the patient, in good general health but with poor oral hygiene, presented with reduced vertical dimension of occlusion (VDO), insufficient labial support and prosthetic space limited by macroglossia. The patient lamented severe functional problems, related both to mastication and speech, as well as serious esthetic concerns, since the maxillary teeth were not visible at all both at rest and during function.

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Controlled Split Crest and Guided Bone Regeneration (GBR) with contemporary implant placement: rationale and limits of the clinical application in esthetic areas.

Controlled Split Crest and Guided Bone Regeneration (GBR) with contemporary implant placement: rationale and limits of the clinical application in esthetic areas.

The authors’ experience in the medium term.

 

Introduction

According to the current scientific literature, a prosthetically-guided approach should be the first choice for implant placement, even in case of horizontal/vertical alveolar bone resorption. In the last decade, different reconstructive techniques were described with the aim of restoring bone volume.

Among the available techniques, the authors widely experienced and achieved very satisfactory clinical outcomes with the “Edentulous Ridge Expansion” (E.R.E.), introduced by Dr. Bruschi and Scipioni in 1994.

This technique relies upon the healing potential of the spongy bone, associated with the elevation of a partial thickness flap to preserve the periosteum. The intra-bony gap is initially filled by a blood clot that turns into osteoid tissue in about 40 days. After about 90-120 days, the extracellular matrix progressively mineralizes and the osteoblasts mature into osteocytes.

Straumann implant guided-surgery with Codiagnostix Software and immediately-loaded prosthesis

Straumann implant guided-surgery with Codiagnostix Software and immediately-loaded prosthesis

COMPLETE MAXILLARY AND MANDIBULAR EDENTULISM TREATED WITH IMMEDIATELY-LOADED DENTAL IMPLANTS AND SCREWED FULL-ARCH TEMPORARY PROSTHESES


INITIAL SITUATION

The patient referred a clinical history of severe adult chronic periodontitis.
- (7) ortopantomografia
She has been edentulous at the maxillary arch for about 3 years while the latest extractions at the mandibular arch had been made about 6 months before the clinical examination. The patient presented with good general health and oral hygiene. She wore two removable complete dentures unsatisfactory for both function and esthetics.

The Membragel Straumann liquid membrane

The Membragel Straumann liquid membrane

 

AN INNOVATIVE APPROACH TO GUIDED BONE REGENERATION.


The Straumann® Membragel™ is a technologically advanced resorbable membrane that simplifies the clinical procedures of guided bone regeneration (GBR).
The application of the liquid membrane is very easy, fast and accurate. Once it solidifies, the Membragel stabilizes the bone graft material, acting as a barrier for 4-6 months before its resorption. Preclinical data showed that the Membragel is resorbed significantly more slowly than conventional collagen membranes, offering an excellent biocompatibility to surrounding tissues. Due to its gel consistency, it can be placed accurately onto the bone defect, over the graft material. In order to stabilize the liquid membrane, it is sufficient to extend it 1-2 mm beyond the margins of the bone defect.
The use of the Straumann® Membragel™ allows for the formation of as much regenerated bone tissue as it is achieved with conventional non resorbable ePTFE membranes.
The application of such a liquid membrane is indicated in the following guided bone regeneration procedures:

  • periimplant defects (dehiscences, fenestrations);
  • post-extractive sites;
  • horizontal bone defects.

Mandibular full-arch restoration with Straumann implant-supported metal mesostructures and zirconia-based prosthesis: a case report

Mandibular full-arch restoration with Straumann implant-supported metal mesostructures and zirconia-based prosthesis: a case report

A 63-year-old female patient presented with a severe chronic periodontitis at the mandibular arch. Only teeth 33 and 44 were present and had been used as abutments for a resin removable partial denture which did not satisfy the functional and estethic needs of the patient. Moreover, a metal-ceramic crown with a supragingival margin and a mesial metal connector was evidenced on tooth 33; the patient reported that the mandibular front teeth had been previously prepared for a metal-ceramic fixed dental prosthesis, in order to limit the discomfort due to the mobility of such teeth.At the maxillary arch, the patient wore a complete removable denture which was esthetically unsatisfactory but valid to accomplish oral functions.
edentulia mascellare

Implant positioning in the Esthetic zone

Implant positioning in the Esthetic zone

 

Single tooth replacement has always been one of the most complex challenges for the implantologist. Patients’ expectations nowadays are very high and the slightest error in the operation management can cause aesthetic damages of various degrees. In order to achieve a good result it is fundamental to insert the implant in a prosthetically guided position using also surgical stents: these are of paramount importance to have reference points when surgery is performed. As a matter of fact, it is not the implant that has to be positioned where the bone is present, but it is the bone that has to be regenerated where the fixture has to be inserted.

In M-D sense, the implant has to be inserted in the centre of the line that joins the adjacent teeth, although, in the case of a maxillary central incisor, the fixture can be positioned slightly more distally than the central counter-lateral due to the need to account for the mesial surplus for the permanent crown. In M-D sense extreme caution has to be taken with the residual distance between the implant and the adjacent teeth: at least 1.5 mm must be left in order to let the papilla mature. The formation of the papilla does not depend on the implant, but on the underlying bone support: as a matter of fact, the soft tissues follow the bone in its reshaping processes.

It has been proven that the average thickness of soft tissues is 4.3mm ± 1mm. Tarnow observed that the presence of the papilla depends on the distance between the bone crest and the contact point: when this distance is = 5mm the papilla will always fully mature. As soon as this distance increases to 6mm, in 50% of the occurrences, the papilla will be open and show the classic “black triangle”. For this reason, when performing a prosthetic restoration on anterior region implants, it is fundamental to try and bring the contact point as apically as possible, in order to avoid soft tissues loss.

When the M-D distance between tooth and implant is less than 1.5 mm the loss of the papilla in that area will be a certainty, due to the bone resorption of the adjacent tooth.

For this reason it is paramount to choose the implant of the right size for each site. In the case of mandibular incisors reduced diameter implants will be used. In the case of maxillary central incisors or canines 4mm diameter implants will be used. In the case of lateral incisors the choice will depend on the circumstances, according to the found spaces. In coronal-apical sense, a sunken implant will have to be inserted with the shoulder positioned 3mm more apically than the line that joins buccally the cementoenamel junction of the adjacent teeth.

Implant placement esthetic zone

Mini maxillary sinus elevation using Sincrest

Mini maxillary sinus elevation using Sincrest

 

MINIMALLY INVASIVE TRANSCRESTAL MAXILLARY SINUS ELEVATION

 

Inserting implants in the back of the maxilla can present considerable technical difficulties. The dentist has often to face coronally-apically reduced bone portions deriving from crestal bone reabsorption or maxillary sinus pneumatisation, especially when in the area there are extractions performed many years before.

In the case the reduced height is mainly due to crestal bone reabsorbtion, before inserting the implants it is necessary to coronally regenerate the bone. This is done in order to avoid using prosthesis with teeth which are too long and would cause an unfavourable crown/root ratio.

On the other hand, when the reabsorption is mainly due to a pneumatisation of the maxillary sinus, it is important to estimate the amount of remaining bone.

As a matter of fact, if the bone height is < 4mm, there is enough bone to achieve primary stabilization of the implant; in this case the operation will be carried out in a single stage performing a mini-elevation of the maxillary sinus and, at the same time, inserting the fixture.

The maxillary sinus mini elevation technique with osteotomes, explained by Summers in 1994, requires the implant site to be prepared up to 2 mm from the sinus floor. At this point, using a concave osteotome, it is time to break the 2 remaining mm of bone; the bio-material is then inserted with the help of the osteotomes, leading to the elevation of the Schneider membrane. In this technique it is the load of the bio-material that elevates the sinus floor: the osteotomes are never to enter in the maxillary sinus.

Once the sinus floor has been elevated, it is time to insert the implant. The mini-elevation technique, when usable, provides remarkable benefits in respect to the standard elevation of the sinus floor.

With this technique, it is indeed necessary for the patient to undergo just one operation, the morbility is considerably lower than in the standard elevation, vascular complications are noticeably reduced and prosthetic rehabilitation times are appreciably shortened.

One disadvantage of this technique is that the surgeon operates blindfold, without seeing directly: this greatly increases the risk of tearing Schneider membrane – sometimes being just a few tenths of millimeter thick.

In this work we will analyze a new device, made by Meta, that should make it possible to elevate the sinus floor in a safer and more controlled way.

The Sincrest is a transcrestal maxillary sinus floor elevation kit made up of burs for electric handpiece, depth stops of various heights and a manual osteotome. The manual osteotome was designed to achieve the controlled fracture of the sinus floor by the maxillary sinus mucosa without damaging it.

The patient, aged 64, non smoker, came to our observation complaining about a low chewing efficiency after the maxillary sixths were extracted many years before and not replaced with a prosthesis. The X-rays show a bone with reduced height because of the pneumatisation of the maxillary sinus.

From endo-oral X-rays made using Rinn Digital Sensor Positioning Aids and a CAT, the residual height is estimated to be less than 8 mm. It is thus decided to insert the implant and at the same time elevate transcrestally the sinus floor using the SinCrest device.

Sonosurgery Komet sonic tips

Sonosurgery Komet sonic tips

 

ERE (Edentulous Ridge Expansion) TECHNIQUE IN TWO STAGES.

 

In implant-supported prosthodontics there is often the need to insert implants with shapes and dimensions adequate to the teeth to be replaced, in line with the load forces and allowing the creation of an ideal emergence profile of the crowns.

These issues often force the surgeon to expand the remaining bone crest using procedures aiming at that goal. Among all the known “augmentation techniques”, a recent revision of scientific literature indicates the split-crest as one of the most highly predictable surgical methods, with a success rate of 98-100% (Chiapasco 2006) and the lowest occurrence of volumetric shrinkage during and after healing. In the case under examination, the splitcrested technique – to be more specific the ERE (Edentolous Ridge Expansion) (Bruschi and Scipioni) – was used; the surgical protocol of this technique of ridge expansion requires a partial thickness flap, not to cause cortical bone periosteum loss.

The tissue is subsequently repositioned apically; both the gingival wound and the mineralized tissue are made heal for second intention. The implant was made transmucosal by inserting the healing abutment in the surgical phase. When one faces a particularly thin ridge with little marrow or a not very elastic bone, difficult to distract, it is better to adopt the two-stage technique, allowing 40/50 days between the two operations. It is well known that in the first stage of its healing process, the bone goes through its osteoclastic phase of healing, losing part of its mineralized component and making the tissue structure much more elastic (woven bone): this feature makes it much easier to distract it.

Following the protocol, to execute the primary sagittal and release incisions – needed to plan release lines of the bone walls to distract – there is a wide choice of instruments that can be used: manual, rotary, reciprocating, piezoelectric, etc.

The latest instrument coming out for this purpose uses the micro-vibrating sonic movement of air-driven handpieces (e.g. Sonicflex kavo). Sonosurgery bonetips “sonic” instruments are made by Komet (Gebr. Basseler DE): they come in 3 shapes that are well suited to reach any place of possible operation within the mouth, even the most inaccessible. One of the most important features of these tips is to have a very thin incision section (0.2 mm), impossible to obtain with other known instruments used for this purpose, not even the piezosurgical ones.

This feature allows to spare precious bone and, at the same time, does not cause heating; as a matter of fact, the small metal mass of the blades limits the building up of heat, which is immediately dissipated. Moreover these instruments have a bone tissue selective cutting feature and ensure the most absolute respect to the integrity of soft tissues: this is due to the slow movement, compared to other instruments, but especially because there is no need to exert pressure during the use.

Controlled bone expansion

Controlled bone expansion

NEW CONTROLLED BONE EXPANSION TECHNIQUE: MULTI-DISCIPLINE CLINICAL CASE (SURGICAL AND ORTHODONTIC PART)

PROSTHESIC PHASE

 

In implant-prosthetic rehabilitation, the presence of horizontal or vertical bone re-absorptions represents one of the most frequent anatomic limits impeding implant positioning. When bone areas are not suitable for implant positioning, reconstruction techniques can be used to restore bone anatomy. These techniques allow implant inserting of appropriate number and length for a correct dental arch restore.

In case of severe horizontal crest atrophies, the technique used to restore a correct vestibular-oral dimension, are the following:

  • regenerative techniques (Guided Bone Regeneration);
  • bone grafts;
  • expansion techniques;
  • bone distraction;
  • crest sagital osteothomy (ERE);
  • extension Crest ;
  • combined techniques (regenerative techniques, expansive techniques)

Edentulous bridge expansion (ERE) technique has been created in 1986 and presented 2 years later by Dr. Bruschi and Dr. Scipioni. The technique has been improved during the past years. Nowadays, it is used to reestablish orofacial dimensions suitable for alveolar atrophic crests during implant introduction without membrane induction and without bone-inductor or bone-conductor materials induction.

A study conducted on edentul sites treated with ERE technique confirmed that in the intraosseous rupture surgically created there is a complete bone regeneration. Interestingly, the same bone integration level is obtained on control sites treated with a traditional surgical implant technique. This technique uses the normal regenerative potential of the spongy bone, improved by a careful surgical approach with a periosteum conservation, together with recovery techniques by second intention. Intra-osseous rupture is, at first, filled by a clot; in the next days (about 40), there begins the formation of osteoid tissue that progressively (after 90-120 days) matures by increase in matrix mineralization and transformation of osteoblasts in osteocytes.

There are two principal prerequisites for bone regeneration after slit crest:

  1. a solid nutritional basis, with a minimum thickness of 1-1,5 mm of osseous flaps;
  2. an abundant blood flow necessary for newborn trabeculars.

This allows to avoid fenestrations, dehiscences or necrosis of vestibular osseous plate during the introduction and recovery phases of osteointegrated implants.

ERE technique is indicated in blade knife crests with a height of 10 mm minimum and a thickness of 4 mm minimum. It is performed by a crestal cut to release a flap of partial thickness edge in a vestibular and palatal direction. If necessary, two cuts are carried out in the mesial and distal limits of the surgical area. After the edges are raised, we proceed with cutting the bone in the crest center (5-7 mm deep); secondarily, we carry out two parallel trans-periosteal cuts. Thus, there result two vertical grooves in the vestibular cortical plan. A scalpel is inserted in the crest incision and beaten softly with a percussion hammer, until it reaches the lower part of the crack; at this point the scalpel will be used as a lever to dislocate the buccal plate in a vestibular direction.

The recovery period of implants inserted with the ERE technique is identical to the prescribed period for classic procedures. Nowadays, there seems to be a higher stability of the bone regenerated by bone expansion through time than that obtained by guided bone regeneration (GBR) techniques that tend to reabsorbed through time.

The disadvantage of the ERE technique is the risk of fracture of the vestibular wedge during the scalpel action, not being able to control the power during hammering. To avoid this risk the flap is cut at a partial thickness to guarantee blood flow of the cortical bone in case of fracture. On one hand the partial thickness flap preserves us from this risk, on the other hand not detaching the periosteum does not enable us to associate bone regeneration techniques.

Some years ago the Extension crest technique was presented.This technique, following incision in crest and bone expansion of 2 mm, is based on the insertion of a 2 mm thick distractor, activated by a screw and immediately bringing to the superior dental arch, or after a few days to the inferior arch to the crest expansion. This technique permits to control the expansion and to make it more predictable. A big disadvantage, instead, is the tool thickness. Actually, there exist 3 mm diameter implants of predictable use. Therefore, when the bone is expanded of 2 mm to introduce the Extension Crest there would be only 1 mm of expansion left for implant insertion. For all these reasons in the clinical practice during these last 4 years we tried to improve a controlled bone expansion technique that allows us to give predictability to the technique of bone expansion in order to obtain the detachment of a total thickness flap and so to associate guided osseous regeneration techniques.

The use of the scalpel cannot be foreseen and its’ power not being continuous may cause the fracture of the bone fragment with its consequent dislocation. Controlled osseous technique includes the use of manual screw expanders. Manual screw expanders can be checked more easily by the user, they allow to check with a ratcher its expansion power. In particular, they allow minimum expansion movements, each screw movement being of 0,2 mm. These screws should have a decreasing in its conical shape. This reduces expansion powers on the crest edge which is usually the weakest point.

Clinical case

The patient of this case presented a medial survey until the apex of the element n.11 caused by a root fracture not immediately diagnosed and a 3 mm diasteme between the 2 superior central teeth. The extraction of this element was thus necessary as was the consequent implant rehabilitation following 9 months from the extraction. Meanwhile, it was necessary to put a temporary prosthesis on the edentule saddle and considering that the patient wanted to fill the space between the two central teeth it was also required an orthodontic movement to improve in a mesial-distal way the space for a future implant site and the prosthetic dental crown. The patient declined at the same time the multibrackets vestibular therapy which would have allowed at the same time the maintainance of the temporary tooth.

Straumann implant with bone regeneration (GBR) by using Bio-Gide And Bio–Oss

Straumann implant with bone regeneration (GBR) by using Bio-Gide And Bio–Oss

 

COMPLEX MULTIDISCIPLINARY IMPLANT-ORTHODONTIC TREATMENT: ESTHETIC INVISIBLE ORTHODONTIC THERAPY COMBINED WITH IMPLANT SURGERY AND SIMULTANEOUS BONE AUGMENTATION

 

The present case report is aimed at presenting an implant treatment associated with both a simultaneous guided bone regeneration (GBR) and an orthodontic therapy. The complexity of the case required the use of a resorbable Bio-Gide membrane and a bone graft made up of autogenous bone together with Bio-Oss. Simultaneously, an esthetic orthodontic therapy was performed by means of ceramic brackets and miniscrews at the maxillary arch and using an invisible bracketless approach by means of preactivated retainers at the mandibular arch.

It is worth remembering that the type of membrane is a critical factor for the success of bone augmentation procedures. Nowadays, it is widely accepted that only non resorbable Gore-Tex membranes can guarantee a predictable result in complex bone reconstructions. Adequately stabilized resorbable membranes can be considered a viable alternative only in easier clinical cases and in the presence of a good regenerative potential. In order to properly stabilize resorbable membranes, nowadays resorbable pins are available (Resor Pin, Geistlich); differently, operative tips may be adopted, just like the use of membrane strips opportunely cut, as proposed by Prof. Massimo Simion, or creating a hole in the membrane so a sto stabilize it around the implant neck.

As to this clinical case, the patients lamented recurrent abscesses in region 14. First canine and molar class on both sides with a deep bite and mandibular crowding were evidenced.

Straumann implant with guided bone regeneration (GBR) with Bio-gide and Bio-oss
Biogide
Bio oss

A vertical radicular fracture of tooth 14 was noticed. Such tooth had been previously restored by means of a metal cast post and a metal-ceramic crown; consequently, the extraction of tooth 14 was compulsory.

In order to solve the orthodontic problems, buccal ceramic brackets were used at the maxillary arch together with mini-screws to make the opening of the deep bite faster. On the contrary, pre-activated retainers were used at the mandibular arch, in order to expand the intercanine distance and to line up the anterior mandibular teeth.

Mini screw
Orthodontic screw
Retainer
Active retainer
Orthodontic retainer

The choice of using brackets at the maxillary arch was due to the necessity of maintain a provisional resin shell in region 14. Such shell was fastened to the orthodontic wire by means of a metal ligature. In order to control the rotation of the resin shell, a continue ligature from tooth 13 to tooth 15 was made alternating the rotation spin mesially and distally to the provisional shell.

As we can also see in further cases in the present blog, to date it is preferable to avoid such a problem in the absence of teeth using rigid orthodontic wires lingually to fasten provisional crowns, so as to perform a bracketless lingual orthodontic therapy also in such cases.