The success rate of immediate tooth replacement has been well documented in the literature. To achieve long-term success of dental implants, evaluation of the dimensions of the resorbing alveolar process must be accurate because an implant should be surrounded by at least 1 mm of bone. To minimize facial gingival recession, an intact labial bony plate along with an osseous-gingival relationship of 3 mm on the facial aspect of the failing tooth has been suggested. This article mentions a technique wherein the amount of available labial and palatal bone of an extracted socket can be assessed by using the extracted tooth that is to be replaced with an endosseous implant and a ridge mapping procedure without reflecting the flap.
The use of dental implants to support prosthodontic restorations has a high success rate, and the success rate of immediate tooth replacement has also been well documented in the literature.1–7 Careful diagnosis and treatment planning with proper evaluation of the dimensions of the available alveolar bone is an important prerequisite for a favorable outcome. To minimize facial gingival recession, an intact labial bony plate along with an osseous-gingival relationship of 3 mm on the facial aspect of the failing tooth has been suggested in the literature.8–10
Facial cortical plate over the roots of the maxillary teeth is oftentimes thin and porous. Periapical infections as well as surgical treatments (ie, apecetomy) can cause resorption of the labial plate, further leading to bone migration to a more palatal position and later possibly requiring a bone augmentation procedure prior to implant placement.11
Proper treatment planning is essential to overcome gingival recession that occurs because of loss of the labial plate. Assessment of the buccolingual dimension of the osseous ridge is also needed for proper treatment planning. The buccolingual ridge width can be evaluated by computerized tomography.12,13 An alternative method is ridge mapping using a caliper device under local anesthesia.14 A simple method is presented to determine the available amount of labial and palatal bone around the tooth to be extracted and immediately replaced with a dental implant.
The technique is explained in relation to the clinically mobile maxillary left central incisor of a 21-year-old male patient (Figure 1). The etiology of tooth mobility was trauma. After clinical examination, the prognosis of the tooth was poor; hence, extraction of the tooth and immediate replacement with an endosseous dental implant was planned. Once the procedure was explained to the patient, a maxillary arch impression was made with alginate (Zelgan, DPI, New Delhi, India) using a stock tray (Jabbar, India) to get a diagnostic cast. A stent was made using a vacuum adapted thermoplastic sheet on the cast, covering the teeth to be extracted and a few adjacent teeth. As performed in stents made for the ridge mapping technique, a series of calibrated 2-mm holes was made on the labial and palatal region of the stent covering the tooth to be extracted.14
Ridge mapping procedure was performed clinically using the stent.14 Following administration of local anesthetic (Lignox 2%A, Warren Pharmaceuticals, Mumbai, India), the stent was placed in the patient's mouth and calibration was done with endodontic files with a rubber stop to measure the thickness of the mucosa covering the bone along the labial and palatal mucosa covering the bone of the mobile teeth (Figure 2).
Another maxillary arch impression was made using an elastomeric impression material of putty consistency (Reprosil, DENTSPLY International, Woodbridge, Canada) using a stock tray (JAB stock tray, Jabber & Co, Uttar pradesh, India).
On the day of surgery, the region was infiltrated with local anesthetic (Lignox 2%A), and the tooth was extracted carefully so as not to fracture the tooth.
The extracted tooth was cleaned and an impression of the same had to be made with elastomeric impression material (Reprosil). The tooth impression was poured with modelling wax or inlay wax (Hindustan modelling wax, Hindustan Dental Products, Hyderabad, India). The wax pattern of the tooth back was reoriented in the impression in the earlier recorded elastomeric putty impression, and the impression was poured in a Type III dental stone (Kalastone, Kalabhai, Mumbai, India) (Figures 3 and 4).
The waxed tooth was removed from the cast, and the cast was sectioned along the long axis of the extraction socket as performed in the ridge mapping technique. The stent was reoriented on the sectioned cast. The ridge mapping measurements were transferred to the sectioned cast. The markings were joined on the sectioned surface of the cast (Figures 5 and 6). As a result of joining the markings, the amount of labial and palatal width of the bone could be evaluated. Based on the thickness of the labial and palatal bone covering the socket, placement, selection of implant size, and positing could be planned.
The reduction of residual ridge is chronic, progressive, irreversible, and cumulative. The rate of bone resorption varies between individuals and in different parts of the jaws in the same individual.15 Even though this important and basic finding has been accepted, the contour of the soft tissue covering the resorbed ridges may often present a misleading picture of the extent of bone resorption.14 This technique will help the surgeon understand the thickness of the labial plate, especially the apical region without reflecting the flap. This technique will also help the surgeon know whether adequate bone coverage can be achieved after the implant placement and whether a bone graft is needed.