OSSEOINTEGRATION IN IMMEDIATE LOADED DENTAL IMPLANTS

IMMEDIATE LOADED DENTAL IMPLANTS

Advantages of immediate placement

1  Implants    in  fresh    extraction    sites    can be  placed    in  the  same    position  as    the extracted  tooth,    minimizing  the  need  for angled abutments.

2 Osseointegration   is   more   favorable   when implants   are   placed   immediate   following an extraction.

3 The  bony  receptors  are  preserved  by preventing   atrophy  of   the   alveolar   ridge,  preventing   recession  of   the   mucosal   and gingival   tissues.   Reports   indicate   that   a significant  amount  of  crestal  bone  is  lost by delaying the load on implants.

4 Non-functional    restorations    can    be   provided    for  better  esthetics,    especially    in the anterior region.

5 lmmediate placement of implants keeps contaminants away from the socket.

6 Waiting  times  for  primary  healing  of the   soft   tissues   and   regeneration   of   the   osseous structure are eliminated.

7 More   patients   will   opt  for  implant   treatment  (no  waiting  for  healing,    immediate restoration

 A Video Of Dental Implant Procedure

Rationale Behind Axial Positioning Of Implants

Axial Positioning Rationale

Implant positioning in relation to its axial level influences the amount of exposure the final restoration will receive, which in turn dramatically affects the esthetic outcome of the restoration (Jansen and Weisgold 1995). Apico-incisal positioning is no less important than the mesiodistal and labiopalatal positioning aspects of the implant. Unfortunately, surgical templates that offer apicoincisal positioning guidance for functional or esthetic implant placement are few. They are often difficult to fabricate and they are not cost effective. Most of the recent computer-generated templates have a metallic stop to control the apical extent of the drill. The optimal axial positioning of the implant head allows the final restoration to emerge naturally through the marginal gingival tissues with no violation to the gingival sulcus (Wheeler 1974), allowing the contours of the restoration to develop in a progressive manner within the peri-implant soft tissue housing. As a result, the final prosthetic result appears as if it emerges naturally.
Several factors control the location of the implant head in an axial dimension, including
  (1) the amount of space available for restoration,
  (2) the topography of the remaining bone,
  (3) the marginal gingival location of the adjacent natural teeth, and
  (4) the selected implant diameter.
The optimal axial location of the implant head is necessary due to the anatomical difference between the fixture morphology and that of the natural tooth at the cervical level. A morphological transition from the narrow circular implant neck from the implant head to that of the natural tooth form is naturally required.
The reference location of all axial implant positioning is an imaginary line connecting the gingival zeniths of the adjacent natural teeth. There is a greater urgency for restoring natural gingival contours surrounding the new restorations when a natural tooth reference is missing and multiple adjacent implants are to be used. These implants should be placed at the alveolar crest within the circumference of the missing teeth to be restored. This enables the clinician to develop appropriate natural embrasures on both sides adjoining the restorations and duplicate a natural gingival profile (Potashnick 1998). The ideal apico-incisal implant positioning places the implant head 2 mm to 3 mm apical to the line connecting the gingival zeniths of the adjacent natural teeth. This subsequently allows “running room” throughout the biological width of the implant when it is correctly positioned in an apicoincisal plane (Parel and Sullivan 1989), as shown in figure.

An illustration showing the ideal axial positioning of the implant, 2–3 mm from the line connecting the gingival zenith of the natural teeth.

The “running room” is a space of 2 mm to 3 mm in depth and it surrounds the implant head circum-ferentially, as shown in Figure.

The ideal distance from the gingival zenith to the implant head. The blue line represents the gingival zenith, and the green line represents the optimal implant axial position.

This room allows for stacking or building up of prosthetic components to create the natural gingival emergence of the final restoration. If any modification or expansion of the gingival tissues to match the original crown size takes place in this particular space, the progressive use of the pro-visional restoration will develop the original crosssectional shape of the missing natural tooth. The use of anatomical abutments has not proven to be more effective than the progressive use of the provisional restoration. Because the gingival tissue does not have a memory to keep its original dimensions without existing support, the peri-implant soft tissue tends to collapse and regain its original circular shape (due to the pressure from the circular collagen fibers surrounding the biological seal) upon its removal from the gingival sulcus. Clinically speaking, natural biological contours could be replicated without the need for anatomical abutments. Provisional prostheses have proven to give an optimal gingival influence with great clinical predictability.

An illustration showing the difference in cross section between implant and natural tooth and the running room.

Implant diameter has an inverse relationship to the amount of subgingival sinking. It influences the amount of axial sinking of the implant head, because implants with wide diameters eventually require less space for making the transition into a natural tooth form than narrow-diameter implants. Bear in mind that not all the biological concepts are violated. The screw design implant ranks first to allow a more precise axial placement than the cylindrical designs. Its mechanical characters allow control of the depth while threading the fixture in the bone. The cylinder design, on the other hand, requires the use of an implant retrieval tool to adjust the implant’s optimal vertical position, which makes the procedure difficult to control.

An illustration showing that wider implants require less apical positioning.

Gingival zenith of the adjacent natural teeth is considered to be the landmark or the reference in apico-incisal implant positioning. Therefore, for a number of reasons, it is recommended that the location of the implant head be related to a line connecting the gingival zenith of the adjacent remaining natural dentition rather than to a line connecting the CEJ or the crest of the ridge. For instance, the gingival zenith is not a static landmark; it sometimes moves apically, such as in the case of gingival recession, because it represents the actual clinical marginal level of the soft tissue at the time of implant placement. In contrast, the CEJ is a constantly static landmark. It follows a uniformly fixed scalloped path along the root surface. It also pursues a wavy course that has a rise and fall on both buccolingual and interproximal margins. This scalloped line does not move when gingival recession occurs, thus it does not allow for optimal apicoincisal positioning in the case of gingival recession and in cases of placing an implant in unbalanced soft tissue margins.

Two unsymmetrical gingival margins: the blue line represents the actual gingival zenith, the red line represents the CEJ, and the green lines show the calculation of the distance form the deepest point of the gingival zenith to the implant head represented in the black line.

Also, the wavy course of the CEJ does not give a table reference with which to measure. The use of the deepest part of the gingival zenith allows the final implant-supported restoration to attain the same marginal level as those existing around natural dentition, as shown in following figure.

In the case of gingival recession, it is impossible to relate the axial positioning to the CEJ. The red line represents the CEJ, the blue line represents the actual gingival marginal position, and the green line represents the osseous crest levels.

The crest of the ridge is a less than ideal reference point for making a measurement to relate the implant head because the nature of bone resorption sometimes makes it variable in its levels. In other words, in many instances the osseous housing is not the optimal land-mark. Soft tissue thickness on top of it can be variable as well, which might lead to unpredictable variable measurements, as shown in following figure.

In cases of vertical bone resorption, the implant head can be located over the osseous crest, which proves the fact that the implant head should be related to the line connecting the gingival zenith. The green line represents that osseous crest, the black line represents the implant head level, and the blue line represents the gingival zeniths.

For example, when the alveolar ridge has undergone a process of vertical osseous resorption, the implant head will eventually be situated above the bone level. Therefore, the osseous crest should not be taken as a reference measuring point.

An illustration showing the three different positioning possibilities.

Implant Guidelines for the Restorative Dentist lecture.....ppt

Advantages of Dental Implants Over Dentures or a Fixed Bridge,Socket Preservation,Multiple Tooth Replacement

What is a dental implant?

Today, the preferred method of tooth replacement is a dental implant. They replace missing tooth roots and form a stable foundation for replacement teeth that look, feel and function like natural teeth. Dental implants also help preserve the remaining bone by providing the stimulation previously provided by the natural tooth roots.

The most common dental implants are called "root form implants." They are similar to teeth in that they mimic the shape of the roots of teeth. They can be used to support individual teeth or to help anchor removable dentures. Using local anesthetic (freezing) and oral sedation, the implants are surgically placed under the gum and into the bone. The healing period for dental implants varies depending on the location and the health of the bone.  It can be as little as 6 weeks or as much as four months. Some form of aesthetic temporization is always placed in visible areas. Once the implant is biologically attached to the bone, a post (abutment) is inserted inside the implant. The post becomes the extension to which a crown is attached. 

Implants are made of a bio-compatible material called titanium, which cannot decay. One advantage of implants is that they stimulate bone growth, and thus, prevent future bone loss. Bone that disappears when a tooth is removed can only be replaced with a bone graft. It is why dentists are trained to do immediate placement of the implant fixture after atraumatic extraction of a unsalvageable tooth.

What are the advantages of choosing dental implants?

•  Maintain Anatomy: If you have missing teeth, the bone begins to shrink over time. Unhealthy bone loss can make your jaw line recede and change your facial structure. Dental implants can help prevent deterioration of the jawbone so your face retains its natural shape.

•  Keep your healthy teeth: A better long-term alternative to bridgework, dental implants eliminate the need to grind down healthy teeth when replacing one or more adjacent teeth. Your own natural healthy teeth are not compromised.

•  Security: Securely anchored dental implants do not slip or move. This eliminates some of the key problems of dentures, including poor fit, gum irritation and pain from exposed nerves. The result is superior comfort, reliability, and freedom from embarrassment.

Advantages of Dental Implants Over Dentures or a Fixed Bridge

•  Aesthetic:   Dental implants look and feel like your own teeth! Since dental implants integrate into the structure of your bone, they prevent the bone loss and gum recession that often accompany bridgework and dentures. No one will ever know that you have a replacement tooth. 

•  Tooth-saving:   Dental implants don't sacrifice the quality of your adjacent teeth like a bridge does because neighboring teeth are not altered to support the implant. More of your own teeth are left untouched, a significant long-term benefit to your oral health! 

•  Confidence:   Dental implants will allow you to once again speak and eat with comfort and confidence! They are secure and offer freedom from the irksome clicks and wobbles of dentures. They'll allow you to say goodbye to worries about misplaced dentures and messy pastes and glues. 

•  Reliable:   The success rate of dental implants is highly predictable. They are considered an excellent option for tooth replacement. 

•  Immediate Placement  Fractures, decay, blocked canals and other conditions can prevent the successful completion of root canal treatment. Fortunately, if this is anticipated, it is possible to remove the tooth and immediately replace it with an implant.

How do dental implants work?

 The “root replica” fixture made of titanium is inserted in channel created in the jaw by precision instruments that control heat, speed and any variable that could affect a successful outcome.  After osseointegration (when the surrounding bone has bonded to the implant), a replacement tooth is secured to the top of the implant. This new tooth looks, feels and performs similar to your natural teeth.

Who is a candidate for dental implants? 

Anyone who is missing one or more of their teeth due to injury, disease or decay is a candidate for dental implants. If one, a few or all teeth are missing, dental implants in conjunction with a crown or bridge can replace those teeth. Occasionally, older patients express concern that their age may prevent them from enjoying the benefits that dental implants offer. However, health is more of a determining factor than age.  A careful evaluation of your dental and medical health history must be made to determine whether you can safely have a tooth removed. If you're healthy enough to have a tooth extracted, you're healthy enough to receive dental implants.  

Is there any pain or discomfort involved? 

Most patients report very little discomfort and that they were much more comfortable following the procedure than they anticipated. Anesthesia and patient sedation are used to eliminate any discomfort during the procedure. 

How will I benefit from dental implants?

The benefits of implant treatment include appearance, the enhanced ability to chew and enjoy your food, and often protection of your remaining teeth and jawbone. Dental implants offer many benefits never before available for the treatment of missing teeth. In short, dental implants will look, feel and function like your real teeth.

How long will the treatment take?

Treatment time will vary depending on your particular situation. Nowadays it is often possible to get well-functioning and esthetic looking teeth within a few days. In some cases it may be necessary to wait longer before finishing the restoration in order to obtain an optimal result.

What is involved in the implant procedure?

 The dental implant process involves several steps that take place over a time period that averages from literally immediate placement and loading to 6 months. The typical process will include:

•  Pre-treatment consultation: After a careful evaluation of your dental and medical history, your practitioner will determine if you are a good candidate for dental implants. If you are, you will then have a thorough consultation before your treatment begins.

•  Initial implant placement: Your practitioner places the dental implant into your jaw while you are under either local or general anaesthesia. Over the next several months, bone will heal to the surface of the implant, anchoring it into position. Depending on your particular case, an additional minor procedure creates an opening through which your artificial tooth will emerge.

•  Implant prosthetic attachment: During this phase, your practitioner painlessly attaches a prosthetic "post" to the implant. An impression will be taken, and soon after, an artificial replacement tooth will be created for a natural restoration.

Proper maintenance: Your dental practitioner will guide you on the proper care and maintenance of your new implants before, during and after the procedure. By following a regular routing of careful oral hygiene and regular checkups, your implants will look, function and feel great for many years to come.

Will I ever be without my teeth?

This depends on your situation. Most patients can leave the office wearing some type of temporary prosthesis.

How much will it cost?

The fee for tooth replacement with dental implants will depend on several factors, including the number of teeth being replaced and the number of implants required to support your replacement teeth. It is important for you to know that you do not necessarily need an implant for each missing root. Some additional procedures may be required prior to the placement of your dental implants to ensure the long-term health of your dental implants. To obtain a specific fee estimate, it is necessary to have a doctor examine your mouth. After a diagnostic examination, your dentist will recommend the treatment that is best for you and what your investment would be for the procedure.

How long do implants last?

Modern dental implants have been maintained in individual cases for more than twenty years.  An implant, although made of metal, still requires continued care after placement.  This includes patient home care and professional maintenance.  The life of the implant varies with factors of patient health (diabetes, HIV, metabolic bone disease), patient habits (smoking, oral hygiene) and structural overload. It is impossible to predict exactly how long an implant will last, therefore it is impossible to predict or guarantee success.  If an implant fails it may be replaced, however the prosthesis (overdenture/crowns) will need to be remade.  It is not uncommon to have success rates over 95% in the field of dental implants. 

Is it important to take care of the implants after the treatment is completed?

Yes! Maintainance of the implants will help to assure the long-term success of your treatment. You will be responsible for daily plaque removal, which can be accomplished through brushing and flossing around your restoration. Your dentist or hygienist will show you how to properly care for your implants. You should visit your dentist at least once a year for maintenance appointments.

Single Tooth Replacement

If a single tooth is missing and has been replaced with a removable partial denture or a fixed bridge, an implant-supported crown may be a better alternative. Single tooth replacements look and feel natural and function as a natural tooth

•  Do not compromise adjacent teeth

•  Preserves surrounding bone (replaces tooth root)

•  Prevents bone collapse and jaw line recession

•  Oral care same as a natural tooth

•  Restores a secure natural biting strength

•  Restores self-confidence and appearance

 This patient had her upper right central incisor knocked out as a child. Over time, the root resorbed, the crown discoloured and she need to have the tooth removed and replaced. Rather than a fixed bridge, she elected to have an implant placed. One the implant osseointegrated into the jaw bone, a porcelain crown was fitted and the aesthetic appearance even at this level of magnification is excellent. The implant anchoring the crown is never seen and functions just like a natural root functions.

Multiple Tooth Replacement

This procedure is referred to a single stage implant fixture placement. Cover screws are exposed and no secondary procedure is required to uncover the integrated implants.

This patient’s posterior molars had reach the point where nothing could render them restorable and it was decided to remove them and replace them with an implant retained prosthesis.  As you can see, the implants are indetectable, the teeth appear completely natural and as shown in the radiograph, the ability to floss between them and maintain the health of the underlying gums and bone is excellent.  Looks, feels and performs like your natural teeth

Socket Preservation

The area of the jaw bone that holds a tooth in place is called a tooth socket. After a tooth has been removed, the bone that supported this tooth rapidly begins to melt (resorb) away. A socket preservation grafting procedure is performed to reduce the bone loss in the socket.

This procedure is done as gently as possible. In many cases a tooth can be removed gently using newly invented instruments called periotomes. Rather than using a great deal of force with dental pliers (forceps), the periotomes are pushed between the tooth root and bone so that the bone is gently pushed away from the tooth root. The tooth then comes out and the implant can be placed into the residual tooth socket.

There are circumstances that mandate that additional bone be created to address damage to trauma or periodontal disease.  The tooth is gently removed, donor bone is inserted into the tooth socket during the socket preservation grafting procedure. The patient's body uses this donor bone to completely fill the tooth socket which results in less bone loss (height and width). The socket preservation grafting procedure is done immediately after removal of a tooth. There is a waiting period of four to six months after tooth removal before a dental implant is placed into the old tooth's position.

Anchorage in Orthodontics...with ppt lecture and videos

Anchorage is an important consideration when planning orthodontic tooth movement. Unwanted tooth movement known as loss of anchorage can have a detrimental effect on the treatment outcome. Anchorage can be sourced from the teeth, the oral mucosa and underlying bone, implants and extra orally. If extra-oral anchorage is used, particularly with a facebow then the use of at least two safety devices is mandatory.

It has been suggested that more effective anchorage reinforcement may be offered by surgically placed temporary anchorage devices.There is little evidence to support the use of surgical anchorage systems over conventional means of orthodontic anchorage reinforcement. However there is evidence from one recent trial that showed mid-palatal implants are an acceptable alternative to conventional techniques for reinforcing anchorage.

Orthodontic Anchorage PPT


Sprider Screw Temporary Anchorage Device (Procedure Video )


Animation Of Temporary Anchorage


Molar Protraction Using A Plate For Anchorage

DENTAL IMPLANT NOTE ON IMPLANT MODALITIES WITH MAINSTREAM APPLICATIONS

The professionally accepted implant modalities with mainstream applications covered in this note are listed following box. Each of these modalities meets the scientific and clinical criteria for professional acceptance.These modalities are root forms, plate/blade forms, subperiosteals, endodontic stabilizers, and intramucosal inserts. Modalities that are not covered in this note may not lend themselves to mainstream applications because of clinical considerations such as excessive technique-sensitivity, need for treatment in a hospital environment, or insufficient data to demonstrate high long-term survival rates

 Root forms 

 Plate/blade forms 

 Endodontic stabilizer

 Unilateral subperiosteal implant

Intramucosal inserts 

Adjusting plate/blade forms for enhanced parallelism at time of insertion 

Bone growth within interconnecting porosities (left) of diffusion-bonded microsphere interface (right). 

Root form transfer copings for direct impressioning at time of implant insertion 

Stepped body design for insertion into immediate extraction site

CLASSIFICATION OF IMPLANT MODALITIES 

Endosteal Implants 

Endosteal implants comprise one broad category of implants. The most commonly applicable abutment providing modalities are endosteal. In mainstream cases, endosteal implants are placed within fully or partially edentulous alveolar ridges with sufficient residual available bone to accommodate the selected configuration.

Some endosteal implants are attached to components for the retention of a fixed or removable prosthesis. Other endosteal implants are equipped with an abutment integral with the implant body, which protrudes into the oral cavity during healing. Endosteal implant systems are commonly referred to as one-stage or two-stage. Sometimes these terms are used to describe the number of required surgical interventions. In this book, endosteal implant systems that require attachment of abutments or other attachment mechanisms at a visit subsequent to the insertion visit are referred to as two-stage, and those that are equipped with an integral abutment at the time of insertion are referred to as one-stage. Therefore, what some manufacturers call “one-stage,” meaning that only one surgical intervention is required, is what this book refers to as the two-stage semi-submersion healing option, in which a healing collar is placed flush with or up to 1 mm above the gingiva at the time of implant placement, thus avoiding the implant exposure surgery associated with submersion under the gingiva at the time of implant insertion.

Root Forms. 

Root form implants are designed to resemble the shape of a natural tooth root. They usually are circular in cross section. Root forms can be threaded, smooth, stepped, parallel-sided or tapered, with or without a coating, with or without grooves or a vent, and can be joined to a wide variety of components for retention of a prosthesis.

As a rule, root forms must achieve osteointegration to succeed. Therefore, they are placed in an afunctional state during healing until they are osteointegrated. Semi-submerged implant healing collars are then removed, or submerged implants are surgically exposed for the attachment of  components for the retention of a fixed or removable prosthesis. Thus, most root forms are two-stage implants. Stage one is submersion or semi-submersion to permit afunctional healing , and stage two is the attachment of an abutment or retention mechanism.  Semi-submersion of root forms obviates the need for two surgical interventions, which represents an important improvement in the modality in terms of technique-permissiveness. Root form protocols require separate treatment steps for insertion and abutment or retention mechanism attachment whether the healing protocol calls for submersion or semi-submersion.

First-stage submerged (cover screws, above) and semi-submerged (healing collars, below) healing options to achieve osteointegration. 

 Second-stage prosthesis attachment mechanism following healing

A root form can be placed anywhere in the mandible or maxilla where there is sufficient available bone. However, because of the diameter of root form implants, most mainstream treatment involves anterior insertion for single-tooth replacement or restoration with overdentures. With the innovation of the diffusion-bonded microsphere interface, the mainstream applicability of this modality has increased in cases of posterior partial edentulism requiring five or fewer units of restorative dentistry. Tapered smooth and threaded cylinders also are fine choices for anterior edentulism. Following figures show typical mainstream root form cases.

Root forms to support single-tooth replacements

Crowns individually supported by root forms

Root form-supported single-tooth replacement in mandible

 Splinted root forms with coping bar for overdenture retention.

Plate/Blade Forms  

As its name suggests, the basic shape of the plate/blade form implant is similar to that of a metal plate or blade in cross-section. Some plate/blade forms have a combination of parallel and tapered sides. Just as screws and cylinders are both of the root form modality, plate forms and blade forms are both of the plate/blade form modality. Plate/blade form systems are supplied in one-stage and two-stage varieties. One-stage plate/blade form implants are fabricated of one solid piece of titanium, with the abutment contiguous with the body of the implant. Two-stage plate/blade form implants are supplied with detachable abutments and healing collars. The one-stage and two-stage options exist so the practitioner can use the osteointegration or osteopreservation mode of tissue integration, according to the needs of the case.

 Profiles of Generation Ten and Standard plate/blade form implants

Three-dimensional finite element model of plate/blade form with combination of parallel and tapered sides in a mandible 

One-stage (above) and two-stage (below) plate/blade form options

Plate/blade forms are unique among implants in that they can function successfully in either the osteointegration or osteopreservation mode of tissue integration. When mainstream protocols are followed, one-stage implants heal in the osteopreservation mode of tissue integration, and  two-stage implants osteointegrate. As with two-stage root forms, two-stage plate/blade forms require a second treatment step for the attachment of abutments. However, two-stage plate/blade forms are designed to heal in the semi-submerged healing mode, so the second-stage removal of the healing collar and attachment of the abutment does not require a surgical intervention.

As with root form implants, plate/blade form implants can be placed anywhere in the mandible or maxilla where there is sufficient available bone. However, because of their narrower bucco/labio-lingual width, plate/blade forms tend to be applicable in a wider range of available bone presentations, especially in the posterior of the ridges. Plate/blade forms can be used for the majority of implant dentistry candidates, and in 100% of cases in which root forms can be inserted.

Three-unit fixed bridge supported by plate/blade form with natural co-abutment in mandible

Five-unit fixed bridge with interdental plate/blade form support

Endodontic Stabilizer Implants

Although endodontic stabilizer implants are endosteal implants, they differ from other endosteal implants in terms of functional application. Rather than providing additional abutment support for restorative dentistry, they are used to extend the functional length of an existing tooth root to improve its prognosis and when required, its ability to support bridgework. Modern endodontic stabilizers take the form of a long, threaded post that passes at least 5 mm beyond the apex of the tooth root into available bone. Endodontic stabilizers have been designed with parallel or tapered sides, smooth or threaded. The most successful endodontic stabilizers are threaded and parallel-sided, with sluiceways in the threaded crests that prevent apical cement sealant from being expressed into bone by guiding it crestally. The parallel-sided threaded design controls the stress concentration at the apex of the root, protecting against fracture and trauma. 

The endodontic stabilizer functions in the osteopreservation mode of tissue integration, because the tooth root through which it is inserted is subjected to normal physiologic micromovement as it heals. Endodontic stabilizers are placed and the procedure is completed in one visit, as the final step of any conventional endodontic regimen.

The range of applicability of the endodontic stabilizer is dictated by the need for at least 5 mm of available bone beyond the apex of the tooth being treated, and the need to avoid certain anatomic landmarks. Five millimeters of available bone is the minimum that can increase the crown-root ratio to an extent sufficient to affect positively the prognosis of the tooth. In the mandible, the first premolar and the teeth anterior to it are good candidates for endodontic stabilization. The second premolar and molars are over the inferior alveolar canal, and therefore are usually not good candidates for mainstream endodontic stabilization. In the maxilla, the teeth most often treated are the centrals, laterals, cuspids, and the lingual root of first premolars. The second premolar and molars are under the maxillary sinus, and therefore usually are not good candidates for mainstream endodontic stabilization.

Endodontic stabilizers lengthening tooth roots in anterior mandible 

 Endodontic stabilizer lengthening tooth roots in anterior maxilla. 

Ramus Frame Implants

Ramus frame implants have been demonstrated to be safe and effective. They are intended for the treatment of total mandibular edentulism with severe alveolar ridge resorption. Ramus frame implants do not have mainstream applications because of technique-sensitivity. They feature an external attachment bar that courses a few millimeters superior to the crest of the ridge from ascending ramus to ascending ramus. Posteriorly on each side, an endosteal extension inserts into available bone within each ascending ramus. Anteriorly, the bar is contiguous with a plate/blade form type of extension that is inserted into available bone in the symphyseal area.

 Mandibular ramus frame implant with overdenture.

Transosteal Implants

Among endosteal implants, transosteal implants are the most surgically invasive and technique-sensitive. As with ramus frame implants, they are limited to the mandible. Although transosteal implants have proven safety and efficacy, they are not considered mainstream because of their complexity and the demands they make on both the practitioner and the patient. Transosteal implants feature a plate that is placed against the exposed inferior border of the mandible, with extensions that pass from this plate through the symphyseal area, out of the crest of the ridge, and into the oral cavity.This is usually a hospital-based procedure.

 Presentation model of transosteal implant

Subperiosteal Implants 

The subperiosteal implant modality is distinct from the endosteal implant modalities in that the implant is placed under the periosteum and against bone on the day of insertion, rather than within alveolar bone. This modality is used in cases of advanced alveolar resorption, in which the volume of the residual available bone is insufficient for the insertion of an endosteal implant.The subperiosteal implant is retained by periosteal integration, in which the outer layer of the periosteum provides dense fibrous envelopment and anchors the implant to bone through Sharpey’s fibers, and also by retentive undercut features of the implant design. Subperiosteal implants are custom-made and are of four types. Unilateral subperiosteal implants usually are placed in severely resorbed premolar and molar areas of the mandible or maxilla, where there are no distal natural abutments.

 Unilateral subperiosteal implant in mandible.

Unilateral subperiosteal implant in maxilla 

An interdental subperiosteal implant spans a severely resorbed edentulous area between remaining natural teeth. These implants can be used anteriorly or posteriorly in either arch. They are rarely indicated but nonetheless are considered mainstream in the rare cases in which they are applicable.

Interdental subperiosteal implant in anterior maxilla.

Total subperiosteal implants are for patients who have lost all of their teeth in one arch. Such treatment is not considered mainstream but can be performed after experience with a number of unilateral or interdental cases.

Total mandibular subperiosteal implant.

Finally, a circumferential subperiosteal is a modification of a total subperiosteal implant but is used in cases in which several anterior teeth are still in position. Circum-ferential subperiosteal cases are most often mandibular. The lingual and buccal main bearing struts are designed such that the connecting struts are distal to the last natural tooth on each side, allowing the entire implant to pass over the anterior teeth to rest against basal bone. The circumferential subperiosteal is akin to two unilateral subperiosteals that are connected with anterior labial and lingual main bearing struts.

In mainstream unilateral subperiosteal treatment, two surgical interventions are required—the first to take a direct bone impression to obtain a model from which the custom-made implant is fabricated, and the second to place the implant. Although the application of computer-generated bone modeling is promising , it is not yet considered to be a mainstream technique for obtaining an accurate bone model in unilateral cases.

Intramucosal Inserts 

Intramucosal inserts differ in form, concept, and function from the other modalities. They are mushroom-shaped titanium projections that are attached to the tissue surface of a partial or total removable denture in the maxilla[14] and plug into prepared soft-tissue receptor sites in the gingiva to provide additional retention and stability. Thus, they provide support for a prosthesis but do not provide abutments. They are used in the treatment of patients for whom endosteal or subperiosteal implants are not deemed to be practical or desirable.

Intramucosal inserts do not come into contact with bone, so the mode of tissue integration is not osteointegration, osteopreservation, or periosteal integration. Rather, the receptor sites in the tissue into which the inserts seat become lined with tough, keratinized epithelium. In this sense, seated intramucosal inserts are external to the body. Only one appointment is required for the placement of intramucosal inserts.

 Intramucosal inserts are best used in the maxilla. Because of complicated biomechanics, more acute alveolar ridge angles, a wider array of applied forces, and insufficient gingival thickness, placement of intramucosal inserts in the mandible is not recommended.

Large intramucosal inserts in position 

Standard intramucosal inserts in position