The surface of a dental implant plays a significant role in osseointegration, or the body’s ability to integrate the dental implant into the bony structures of the mouth. The idea is that the rougher the implant surface, the easier it will be for the bone to adhere to it. To improve osseointegration, there are a wide variety of implants available with different types of implant surfaces. Acid etched and sandblasted dental implants are popular choices, however, machined implant surfaces are also used. A machined implant surface simply refers to a manufacturing process that was turned, polished, or milled. While many periodontists believe that etched surfaces have a better osseointegration rate than machined implant surfaces, there are a number of periodontists who use machined implants and have success with them. Patients should discuss with their periodontist about the different types of implant surfaces and which one is recommended.
A macrointerlock is a fixation method which mechanically interlocks the bone and the dental implant. This can include the interlocking connections between abutments and implants. Macrointerlocks can also be used to build up fragile teeth before an implant is placed. Following some dental procedures, the canal of the affected tooth can be left hollow which weakens the strength of the tooth and reduces its ability to support an implant. Prior to implant fixation, a macro-lock post may be used to aid in the reconstruction and build-up of such a canal. Without the use of such posts, the tooth may be too fragile or unstable to allow for an implant. Macro lockers can help strengthen the tooth while also increasing the surface area needed for the implant. Macrointerlocks may also provide stability and longevity to the implant as well as to the bone-to-implant interlock.
Although rare, failure is unfortunately something that still occurs with dental implants, even when periodontists take every possible precaution before and after the dental implant procedure. Once an implant is placed, motion of any kind should be avoided until the implant has had enough time to begin the osseointegration process and become more stable. Macromotion is the term used for excessive motion, most often related to trauma. For example, if a patient gets into a severe car accident soon after their dental implant procedure, macromotion that results from the accident may cause the dental implant to fracture or break. Micromotion is the opposite, a term used for the very minimal motion that is typically expected after implant surgery. Too much micromotion can also cause implant failure, so it’s important for dental professionals to educate patients on both and develop strategies to avoid them as long as possible after surgery.
Not all dental implants are designed to hold a crown or artificial tooth. Dental implants can also be used for magnetic attachments designed to match small metal disks or magnets inside a set of dentures. Magnetic attachments allow a patient with dentures to easily keep their dentures in place without the need for denture adhesive cream. Many patients dislike the taste or feel of denture adhesive, and it may not always work as intended. It’s not uncommon for adhesive to fail at the most inopportune times or to be difficult to remove at the end of the day. A magnetic attachment keeps dentures secure while still making it easy for the patient to put in and take out. Magnetic attachments are simply made of a conventional dental implant with a body and a screw, but the abutment is specially designed for use with one or more sets of magnetic dentures.
Dental implants have a low failure rate, however, failure can be caused by a malpositioned implant. Ideally, implants are placed parallel to other teeth, and each other if there are multiple implants. They should also be vertically aligned with axial forced. When a dental implant is incorrectly positioned or improperly angled and defects in the surrounding soft tissue exist, traditional abutments are impossible to use. A custom-angled abutment is necessary. Healing variables can affect the positioning of a dental implant post-surgery. This includes systemic diseases that impact healing like rheumatoid arthritis and diabetes, contours in hard and soft tissues, the abutment manufacturer, the overall positioning of the implant, and the final design of the dental prosthesis to be fitted. Poor adaptation of a dental prosthesis can tax the implant hardware, causing tiny “micro gaps” to be created between the abutment and the implant below. This results in bacterial accumulation.
The mandibular canal is an important inner structure of the mandible, or lower jaw. It is a small canal that contains the inferior alveolar artery and vein, as well as the alveolar nerve. In the ramus, it runs obliquely forward and downward, and in the body, it runs horizontally forward. The mandibular canal rests underneath the alveoli, which it is able to communicate with via tiny openings. Since this canal contains a nerve and both a vein and an artery, it’s important for dental professionals to determine its location in proximity to the desired procedure site. In root canal therapy of the second molar, a dentist must take care not to extend past the tooth root with either the reamer tool or root canal filling material. If an implant is being placed in this area, the attending surgeon must be sure that the placement of implant hardware does not interfere with the mandibular canal.
Mandibular flexure is a complicated deformation process that can occur in the lower mandible. This can result in a change in the shape and width of the mandible arch, as well as protruding mandibular movements. These are caused by the contraction of various masticatory muscles, particularly the lateral pterygoid muscles. There are generally four types of deformation patterns recognized in mandibular flexure: corporal rotation, anteroposterior shear, dorsoventral shear, and symphyseal bending related to medial convergence. These patterns of deformation can result in excess stress on the bone tissue of the mandible. How the stress is distributed throughout the mandible depends on the shape of the mandible, the quality and quantity of bone, and the amount of force the masticatory muscles exert. Mandibular flexure is important for dental implant surgeons to consider, since excess occlusal loads, such as in cases of bruxism, can potentially result in long-term implant failure.
The mandibular foramen is the opening into the mandibular canal. It is located on the medial surface of the ramus of the mandible providing a passage to the inferior alveolar nerve, artery, and vein. The mandibular foramen thus allows these structures to supply the lower jaw, teeth, and part of the chin with blood, nutrients, gas exchange, and sensation. For oral procedures, the dentist or oral surgeon must be aware of the location and size of the mandibular foramen in order to administer a nerve block to numb the teeth and tissues that will be involved. Since a cranial nerve is involved with the mandibular foramen, it’s location must also be known before placing a dental implant to prevent damage to this nerve. The size and placement of the mandibular foramen can differ between patients since factors such as age, skull shape, and facial dimensions can affect its location.
Mandibular movement refers to the muscle- and ligament-activated border and/or intraborder movements of the lower jaw. There are five types of mandibular movements including rotational, horizontal axis, frontal axis, sagittal axis, and translational. Mandibular movement is affected by several factors such as the muscles used in suspending the jaw, mandibular articulation, and the synovial joint system. Study of this movement is important for the fields of dentistry and orthodontics as it describes the concepts related to dental occlusion and the masticatory processes of the jaw. A detailed understanding of each patient’s unique mandibular movement is also required for the proper design and creation of a customized prosthesis. It provides information regarding their occlusal habits and angle of dentition so a truly functional prosthesis can be formed. Information on mandibular movement is also an important part of dental and medical research pertaining to oral health, mandibular issues, and prosthesis design.
A mandibular ramus is a quadrilateral process projecting upward and backward from the posterior part of the body of the mandible and ending on the other side at the temporomandibular joint in a saddle-like indentation (called the sigmoid notch) between the coronoid and condylar processes. It may serve as a source for bone grafting. The lateral surface of the mandibular ramus is the attachment site of the masseter muscle. In bone grafting, the mandibular ramus provides a good source of autogenous cortical graft best suited for the correction of ridge deficiencies prior to the placement of an implant. Grafts from this location generally require shorter periods of healing, show low levels of resorption, and maintain their density. Obtaining graft bone from the mandibular ramus over other possible facial sources also creates less noticeable facial scars or alterations and is less likely to cause nerve or sensory issues or discomfort.