International Journal of Periodontics & Restorative Dentistry, 06/2003

Four case reports demonstrate the effectiveness of indirect anchorage in orthodontics. These cases demonstrate the variety of situations in which absolute anchorage can be applied. A maxillary premolar extraction case illustrates the effectiveness of anterior retraction with this technique. A maxillary posterior protraction case shows the ease with which space closure can be achieved. Dual-arch capability is demonstrated through a four-premolar extraction case. Lastly, a case of severe dental mutilation devoid of any anchor units under conventional methods depicts how effectively distal driving can be accomplished. The technique involves the simple placement of a midpalatal endosseous implant that provides anchorage by indirect means to various teeth by virtue of a transpalatal arch soldered to its abutment. Once stabilized by such means, dramatic movements can be achieved in situations that would otherwise overtax anchor units and result in loss of anchorage. Teeth that would otherwise require stepwise and sequential movements can be mobilized en masse, greatly simplifying mechanotherapy and dramatically shortening treatment time. When no longer needed, the palatal implant is explanted and leaves no permanent deformation or defect after 2 or 3 weeks of healing.

This study used 2-D finite element modeling to simulate cuspal flexure and stresses at the surface and tooth-restoration interface of a restored maxillary molar using three restorative materials; the influence of four inlay/onlay preparation configurations on stress distribution within the complex was also investigated. A buccolingual cross-section of an intact molar was digitized and used to create 2-D models restored with different restorative materials (feldspathic porcelain, high- and low-elastic modulus composites) and tooth preparations (small and large inlays, small and large onlays). Two simulated 25-N oblique loads were applied to the cusps. The tangential stress for each finite element node located at the tooth surface, interfacial stress, and relative cuspal flexure were analyzed. All materials and tooth preparations exhibited similar surface tangential stress patterns, with a definite compressive area at the external cusp ridges, a tensile zone at the occlusal surface, and compression stress peaks at the CEJ. The low-elastic modulus composite showed reduced tensile stresses at its surface but increased tension at the dentin-adhesive interface when compared to ceramics. All types of onlays demonstrated a majority of compressive interfacial stresses, while inlays showed a majority of tensile stresses. The interfacial tension at the dentin level increased with the flexibility of the restorative material. Only the large ceramic onlay displayed almost pure compression at the interface. Composite-restored teeth exhibited increased crown flexure, while porcelain-restored teeth showed increased crown stiffness. Porcelain inlays/onlays featured more detrimental stresses at the occlusal surface but better potential protection against debonding at the dentin-restoration interface compared to composite inlays/onlays. Ceramic onlays/overlays seem to represent an effective answer to restore severely damaged posterior teeth.

An adequate amount of bone, in both width and height, is required for successful implant placement. When alveolar ridges are severely resorbed, the bone volume must be increased before implants may be placed. A variety of grafting techniques that successfully remedy this limitation have been developed, but they often require multiple surgical procedures and a prolonged healing time. This article describes the sinus/alveolar crest tenting technique, which permits successful implant placement in the severely atrophic posterior maxilla without bone grafts or membranes. Clinical healing is complete after 6 months.

The purpose of this study was to determine if patients prefer ultrasonic or hand instruments for periodontal maintenance. A questionnaire of 13 items was answered by 469 patients in three periodontal offices. The results showed a strong preference (74%) for ultrasonic instruments. The possibility of increased compliance because of this preference is discussed.

The goal of this study was to evaluate the histologic composition of connective tissue grafts removed from the area palatal of the first molar through the premolars. In spite of attempts to remove the epithelium, it remained in 24 of 30 grafts (80%). The incisal portion of the connective tissue graft was comprised of lamina propria. The mean depth of the lamina propria was 3.2 mm (65.2% of the graft). Apical to the lamina propria was the submucosa, which was primarily composed of adipose tissue. The mean depth of the submucosa was 2.0 mm (34.8% of the graft). There was no statistically significant difference in the composition of the grafts based on smoking or age. The grafts were successful in producing root coverage. There were 27 patients with Class I or II recession defects in this study; this group had a mean root coverage of 97.9%. This study demonstrated that most connective tissue grafts are not uniform in composition and quite often contain some epithelium. However, all of the grafts were clinically usable and produced a clinically successful result.

The following case report describes the buccal and coronal bone augmentation around an irretrievable tooth using forced eruption and buccal root torque for immediate nonsubmerged implant placement. A mandibular left second premolar with degree 2 mobility, severe buccal bone resorption, and interproximal angular bony defects was subjected to forced eruption and buccal root torque. Five months after this process, the tooth was displaced 15 mm coronally and the root apex faced buccally. Buccal and coronal bone augmentation and soft tissue enlargement were evident at reentry surgery. This technique enabled proper implant placement in a situation where the bone was compromised.

A technique, the "Loma Linda pouch," is introduced for repairing the perforated maxillary sinus membrane during sinus grafting procedures. A collagen membrane is placed against the perforated site and subsequently covers the internal surface of the maxillary sinus. The collagen membrane is then folded along the lateral access window to form a pouch that surrounds and isolates the graft material.

Ninety sites were treated by sinus augmentation therapy using only Bio-Oss (31 sites) or extraction socket and ridge augmentation therapy using only Bio-Oss beneath secured resorbable or titanium-reinforced nonresorbable membranes (59 sites). The results of core biopsies taken at different intervals were discussed in part 1 of this study. A discussion of the use of resorbable versus reinforced nonresorbable membranes as a function of defect morphology is undertaken in part 2. Secured titanium-reinforced membranes were shown to be the most ideal means by which to ensure the final morphology of the regenerated hard tissues.

This article describes the clinical procedure and outcome of surgical treatment of gingival recessions with the adjunctive use of Emdogain gel, an enamel matrix derivative bioactive material for periodontal reconstructive surgery. Six cases with gingival recession on maxillary canines are presented with 12 months of followup. Initial gingival recession averaged 4.8 mm, with a mean probing pocket depth of 2.2 mm. At the 12-month follow-up, a mean of 3.5 mm of root coverage was observed (ie, 73% root coverage, range 60% to 100%). Probing pocket depth averaged 1.7 mm, indicating a 4-mm gain of clinical attachment (range 3 to 5 mm). On a clinical level, mucogingival surgery in combination with the application of Emdogain gel results in predictable root coverage and gain of clinical attachment while maintaining shallow pockets.

This article presents a new diagnostic and simulative method, PSM LABMACHINE, with the aim of the anatomic reproduction of skeletal components of the facial skeleton. The importance of surgical predetermination with the possibility of simulating the planned surgical strategies is here evaluated. The described clinical case demonstrates the importance of planning in the reconstructive surgery of the maxillofacial district, using solid structures as individual skeletal models. The usefulness of a solid structure as skeletal replica for the effectiveness of modeling corticocancellous bone grafts from the iliac crest with an impressive reduction of the work times is highlighted. The high precision of adaptation of grafts to the donor site after modeling is notable.