This section of our website is under revision. Please return again at a later date.

Topics in this section are described in more detail in publications by Dr. Livaditis which are listed in our website section for referring doctors titled Publications. Supporting references by other authors and contributors are cited in the publications. Please refer to these publications for more comprehensive descriptions of the topics.

Matrix Impression Technique (MIT)

The Matrix Impression Technique was introduced by Dr. Livaditis after several years of development. It incorporates the advantages of the major “families” of impression techniques (syringe/tray, copper tube & compound or elastomer, and wash/reline) into one universal impression technique. The term universal applies because it can be used for: (a)one to sixteen abutments; (b) inlays, veneers, crowns, bridges, implants or any combination of abutments; and (c) supra-gingival or subgingival margins and even deep finish lines resulting from fractures or caries.

The MIT facilitates fixed prosthodontic (FP) impressions:

(a) Typically FP impressions become substantially more difficult and less predictably successful as the number of abutments increases. The MIT reduces the complexity of a multiple abutment impression to that of a 1-3 unit impression.

(b) The typical impression, upon removal of the retraction cord, often becomes a race to register the preparation finish line — a race between gingival bleeding and syringing of material. The MIT displaces sulcular hemorrhage at the critical moment during the impression and prevents displacement of impression material by gingival bleeding. The MIT reduces or eliminates the need for tissue coagulation (electrosurgery), astringents, vasoconstrictors, or compressed air. Indeed, syringing material into the sulcus is unnecessary as the matrix delivers material directly into the sulcus simultaneously for all abutments.

The MIT facilitates FP impressions by delivering impression material into the sulcus of all abutment teeth simultaneously. The semi-rigid matrix (yellow, left) is designed to be positioned between the gingival tissue and the abutment. The impression material (purple, left) is gently forced into the sulcus upon final seating of the filled matrix. Any blood or fluids are displaced from the sulcus at the critical moment by the forced and directed material. Impression (right) illustrates how the sulcular blood is displaced while the abutments (premolars) are free of hemmorhage. By Dr. G Livaditis

(c) Syringe/tray impression procedures are most commonly used in combination with some form of tissue retraction. While tissue retraction is still necessary, the MIT eliminates the chaos that occurs under the constraints of a rapidly polymerizing impression material. The setting time of the material is no longer a significant factor for complex impressions since the matrix delivers the material simultaneously to all abutments. By design, the matrix always seats between the preparation and the gingival tissue margin thus directing the impression material into the sulcus.

(d) The MIT produces the optimal “V” form of the sulcular extension of the impression virtually eliminating sulcular tearing of the impression. The MIT can generate an impression including 1-16 prepared abutments in one full arch elastomeric impression.

The concepts supporting the MIT and a complete description of the procedure has been reported by Dr. Livaditis in the Journal of Prosthetic Dentistry (see publications on this website).

Bipolar Electrosurgery (Coagulation)

Electrosurgery has been available in two modalities, monopolar and bipolar, for almost a century. Dentists are familiar with the monopolar mode which utilizes an active cutting or coagulating probe and a grounding (dispersive) plate. The monopolar mode has enjoyed widespread use in dentistry for tissue incision, tissue contouring (“carving”), tissue coagulation, hemostasis, and gingival “troughing” for FP impressions.

Except for use by some oral surgeons having become acquainted with bipolar systems in hospital operating rooms, the bipolar mode has been ignored by dentistry until the start of this millenium. The bipolar mode is characterized by the use of two probes which are typically similar in size and very close in proximity. The current flows between the two probes and the effect on tissue is limited to a zone between the two probes.

Dr. Livaditis has published the first comprehensive review of bipolar elctrosurgery for dentistry and has compared advantages and disadvantages of both modalities. He identified, for the first time in dentistry, a mechanism causing adverse effects or injuries during monopolar electrosurgery. This mechanism, known in medicine for over half a century, can cause tissue necrosis in sites remote from the actual surgical site. Such occurrence may not be evident to the surgeon until later. These adverse effects occur from an electrosurgical  process referred to as channeling, funneling, or current crowding.Dr. Livaditis has demostrated and reported this complication as it applies to pulpotomies and pulp therapy. According to Dr. Livaditis,monopolar electrosurgery should not be used on the pulp or within the pulp chamber of a vital tooth. The dental pulp space provides optimal conditions for tissue necrosis by means of channeling.

It is almost universally accepted that the monopolar mode is superior over the bipolar mode for tissue cutting or incising. It is also universally accepted that the bipolar mode is safer than the monopolar mode. The prudent clinician should consider having both modes available as numerous manufacturers provide electrosurgical units which provide both modes. Warning: Do not attempt to use a monopolar unit in a bipolar manner. The electrosurgical units must be configured specifically for each mode.

Dr. Livaditis has introduced to dentistry precision coagulation. He has combined the titration of energy (by controlling power output and time) using the bipolar mode and the invaluable coaxial (ophthalmological) probes to enable highly precise coagulation of tissue. He has introduced this system to vital pulp therapy (see Vital Pulp Therapy on this website), to gingival coagulation or hemostasis and for other oral surgical procedures. Both electrosurgical modes are compared and bipolar applications in restorative dentistry are reviewed in articles by Dr. Livaditis (see Publications on this website).

The pulp exposure (left)was anticipated as part of the alignment of the central incisors. A recess was created to provide space for an adequate pulp barrier. Hemostasis was achieved with precise bipolar coagulation (with coaxial probe). Mimimal pulp tissue is affected (middle right) with durable hemostasis. Pulp barrier is applied in a dry, clean preparation (right). By Dr. G. Livaditis

The ridge under the planned pontic required recontouring. Scalpel was used to trim excess tissue. Bipolar coagulation with a coaxial probe was used for hemostasis. Note the minimal tissue destruction possible with precision coagulation. Coagulation can be targeted specifically to the small blood vessels responsible for the hemmorhage. By Dr. G. Livaditis

Matrix-formed Composite Cores for Crown Abutments

This section is under revision. Refer to published reports by Dr. Livaditis.

Resin-bonded Retainers (Maryland Bridge Technique)

This section is under revision. Refer to published reports by Dr. Livaditis.

Vital Pulp Therapy for the Inflamed Dental Pulp

This section is under revision. Refer to published reports by Dr. Livaditis.

Partial Denture Revisions While Patient Retains the Prosthesis

This section is under revision. Refer to published reports by Dr. Livaditis.