Deficient Alveolar Ridges Research Articles

Histologic Evaluation of Tissue Response to Hydroxylapatite Implanted on Human Mandibles

The tissue response to hydroxylapatite implants was examined histologically in samples taken from four patients three to six months after the material had been used to augment deficient mandibular alveolar ridges. Minimal inflammation was found, but the implants had not induced new hone formation and were instead surrounded by a fibrous connective tissue scar.

Hydroxylapatite reconstruction of alveolar ridge deficiency with an open mucosal flap technique

A preliminary report on an open surgical technique for mandibular augmentation with hydroxylapatite has been presented. Twelve patients were evaluated from 2 to 20 months postoperatively. Advantages are thought to include better ridge form, maintenance of vestibular depth, and visualization of the mental nerve. In addition, splints usually are not necessary. Disadvantages include increased surgical time, possible lower lip inversion, and soft-tissue characteristics that may require secondary revisions.

Ｃｅｒａｍｉｃ材料の臨床応用に関する研究 ５ 口くう外科領域でのｈｙｄｒｏｘｙａｐａｔｉｔｅ ｃｅｒａｍｉｃｓの使用経験

It is known that hydroxyapatite ceramics have a good biocompatibility and unite directly to the bone tissue. The authors reported it's promising properties as a bone substitute by animal experiments.In this paper, four cases are reported in which hydroxyapatite ceramics were used as an artificial bone. Three types of hydroxyapatite ceramics-dense, porous and particulate-were used for augmentation of deficient alveolar ridges and for implantation to partial bone defects. There has been no adverse reaction of hard and soft tissues such as surrounding bone resorption or inflammatory changes of soft tissues.However, it is considered necessary that long-term follow-up studies of these cases and further basic studies on degradability of hydroxyapatite ceramics and on cases to which respective shapes of ceramics can be suitably applied will be carried out in the future.

Long-term radiographic evaluation of hydroxylapatite-augmented mandibular alveolar ridges.

From six months to four years after alveolar ridge augmentation was performed, the vertical ridge heights of 74 Class III and Class IV alveolar ridge deficiency patients, who had undergone augmentation with hydroxylapatite with or without autogenous cancellous bone, were measured using panoramic radiographs adjusted for magnification errors. No statistically significant decreases in vertical ridge heights were seen when only hydroxylapatite was used, nor were there significant differences between the two types of hydroxylapatite particles used. Unlike other bone onlay procedures, the use of autogenous bone and HA together did not result in significant decreases in vertical ridge height.

Use of durapatite for the rehabilitation of resorbed alveolar ridges

These investigations were undertaken to evaluate durapatite, a particulate, ceramic, nonresorbable bone-grafting material for augmentation of deficient alveolar ridges. A total of 207 augmentations were reported among 198 patients over 24 months. Subjective and objective data showed that durapatite alone was successful for all classes of ridges augmented; height, bulk, contour, and ridge form generally improved and soft tissue overlying the augmented ridges was firm and immobile. Impressions for dentures usually began 4 to 6 weeks after surgery and these dentures remained stable, retentive, and esthetically pleasing throughout the study. Other than transiently altered sensations resulting from mental nerve manipulation during surgery, no other important procedural complications were noted. No infection or bone resorption beneath the implant was observed throughout these studies. Durapatite used in an outpatient setting provides a less costly and more permanent method for alveolar ridge augmentation than do augmentation procedures using autogenous or banked bone.

Use of hydroxylapatite for the augmentation of deficient alveolar ridges

Investigations were undertaken to evaluate nonresorbable, particulate ceramic hydroxylapatite (durapatite) for augmentation of deficient alveolar ridges. One hundred and fifteen augmentations in both jaws were reported for 110 patients over a 33-month postoperative period. Subjective and objective data show that the implant was successful for all classes of ridges augmented; height, bulk, contour, and ridge form generally improved, and soft tissue overlying the augmented ridges was firm and immobile. Impressions for dentures were usually obtained four to six weeks after surgery, and the dentures were more stable, retentive, and esthetically pleasing than the preoperative prostheses and required fewer relinings. Other than transiently altered sensations resulting from mental nerve manipulation during surgery, patients had few complications. No infection or bone resorption beneath the implant was observed throughout these studies. It was concluded that hydroxylapatite particles placed through a subperiosteal tunnel offer a highly successful method of ridge augmentation and eliminate the most serious problems associated with the use of autogenous or banked bone, namely, morbidity, risk, costliness, and poor results.

Alveolar ridge augmentation using nonresorbable hydroxylapatite with or without autogenous cancellous bone

A four-year prospective evaluation of the use of nonresorbable, particulate hydroxylapatite (HA) to augment deficient alveolar ridges was performed. The material was used alone and in combination with finely crushed autogenous cancellous bone. Implants were delivered subperiosteally by syringe injection, usually using local anesthesia for Class I to Class III ridges and general anesthesia for Class III and Class IV ridges. The improved ridge height and width were stable. Postoperative resorption with significant loss of ridge height, frequently seen with rib and iliac crest onlayed grafts, was not observed with HA augmentation. Permanent denture construction began as early as three weeks postoperatively and by four to six weeks if HA was combined with autogenous cancellous bone. It was possible to place mandibular staple implants simultaneously or following HA augmentation. Visor osteotomy techniques were improved by use of HA to produce a wider, more convex stable ridge. Although skin, mucosa, or dermal vestibuloplasties were performed as early as three months postoperatively in a small number of patients, there appeared to be a lesser need for vestibuloplasty after HA augmentation than after onlay bone grafting. In addition, prosthodontists performed fewer denture relines after HA augmentation than after onlay bone grafts. The authors believe the most significant factor accounting for these observations is the firm, nonmobile mucosal base resulting from augmentation with HA. The resultant stable, soft tissue base and improved ridge height and contour have contributed to a comfortable, retentive, stable denture for these patients. The prosthetic and surgical procedures are easier to perform and have produced superior, more permanent results than onlay bone grafts and alloplasts. Preliminary studies also point to exciting possibilities for use of HA as a bone substitute/marrow extender in maxillary and mandibular defects, cysts, and clefts and in osteotomies for orthognathic surgery.

Correction of Alveolar Ridge Deficiencies with Nonresorbable Hydroxylapatite

An evaluation is made of a new dense, nonresorbable form of hydroxylapatite for the augmentation of deficient alveolar ridges. Surgical and prosthetic data are discussed. An evaluation is made of a new dense, nonresorbable form of hydroxylapatite for the augmentation of deficient alveolar ridges. Surgical and prosthetic data are discussed.