Qualitative and quantitative expression of bovine bone mineral in experimental bone defects. Part 1: Description of a dog model and histological observations

BACKGROUND: The purpose of this study was to evaluate histologically the contribution of inorganic bovine bone biomaterial in a new experimental bone defect in dogs at different healing periods and to examine newly formed bone around the grafted mineral particles and their relationship in membrane-protected (test) and non-protected intrabony (control) defects. METHODS: Four round intrabony defects, 5 x 4 mm were made bilaterally (at different times) on the lateral bony mandibular angle in eight dogs. Two defects were filled with bovine bone mineral (BBM) particles and two remained non-grafted but were blood clotted. A collagen membrane covered each defect type (n = 4). This procedure was repeated on the contralateral side at a different given time to obtain two different healing periods in each dog. Thus, four specimens were obtained at 3, 6, 12, and 24 months postoperatively for each healing period. The non-decalcification method (Donath technique) with Stevenel's blue and van Gieson's picro fuchsin staining was used for histological examination. RESULTS: Newly formed bone was observed at all examined defect types. The BBM particles were clearly evident regardless of the healing period. At 3 and 6 months, newly formed bone, woven in nature, was incorporated with the grafted particles. High cellular bone with occasional osteoclasts was noted towards the surface of the mineral particles. No substantial difference was observed between the protected and the non-protected defects except for higher ossified centers around the membrane-protected defects. At the non-grafted sites, the membrane-protected defect showed newly formed bone near the bony walls, and particularly under the membrane, establishing a bony bridge over the defect at the healing periods. The non-grafted unprotected defect (control) showed bone formation only at the base and close to the bony walls leaving a healed concave configuration. At 1 and 2 years, the grafted sites showed full bone healing configuration. However, the grafted particles still dominated the previous defect area and were completely surrounded by the newly formed bone. Osteons and lamellar bone arrangement were established but the bone was still highly cellular and osteoclasts could still be identified. The non-grafted membrane-protected sites showed excellent bone healing although areas of non-mineralized soft tissue were often seen. The control sites healed but still presented with a concave surface configuration. CONCLUSIONS: BBM biomaterial is a highly osteoconductive material. In a 4-wall bony defect, newly formed bone was well evident in establishing excellent bone healing configuration with or without a regenerative biological barrier. The grafted material dominated the experimental sites with no substantial resorption at any healing period up to 2 years observation.     

Clinical evaluation of three different materials used as pit and fissure sealant: 24-months results

To evaluate the retention and caries experience effects of three different materials used as fissure sealants after 24 months of clinical application: a resin-modified glass ionomer cement (A), a flowable resin composite (B) and a compomer (C). One hundred and seventeen (117) teeth were sealed with material A, 119 teeth with material B and 120 teeth with material C. Children were randomly assigned. Each one received only one of the materials studied. Plaque index, dmft score and socioeconomic level were scored at baseline. The clinical exams were conducted 6, 12 and 24 months after application of the sealant. Statistical analysis (Kruskal-Wallis) revealed that there were statistically significant differences between the retention rates of groups A and B and between groups B and C after 2 years, with material B showing better results. After 2 years, 3.1% of the teeth of group A, 4.3% of group B and 6.7% of group C were Carious+Filled. There was no evidence of association between caries presence after 2 years and plaque index, dmft score and socioeconomic level. These results suggest that flowable resin composite had a satisfactory retention after this period of evaluation and all three materials were effective on occlusal caries prevention.     

Effects of plaque disclosing agents on esthetic restorative materials used in pediatric dentistry

The aim of study was to evaluate the color stability of tooth-colored restorative materials usually used in pediatric dentistry after the application of two plaque disclosing agents. Twenty specimens of each material: a resin-modified glass ionomer, a composite resin and an ion-releasing composite resin, were prepared. Baseline color evaluation was performed, samples were exposed to the plaque disclosing agents: a basic fuchsin solution and a fluorescent dye, and new color evaluations were made. The resin-modified glass ionomer stained with basic fuchsin presented the greatest color change in the present study, and the fluorescent dye did not show statistically significant changes among the restorative materials. In conclusion, basic fuchsin dyes should be carefully used in children with a great number of tooth-colored restorations.     

Treatment of gingival fibromatosis associated with Zimmermann-Laband syndrome

BACKGROUND: Gingival fibromatosis is a rare condition characterized by a generalized enlargement of the buccal and lingual aspects of the attached and marginal gingiva. METHODS: This case report describes the periodontal management of a 13-year-old female patient with gingival fibromatosis associated with Zimmermann-Laband syndrome. The patient presented with gingival enlargement involving the maxillary and the mandibular arches, anterior open bite, and non-erupted teeth. Periodontal treatment included gingivectomy in all four quadrants. RESULTS: Histopathologic evaluation of the excised tissue supported the diagnosis of gingival fibromatosis. A significant improvement in esthetic appearance and eruption of the non-erupted teeth were obtained. The patient was referred for appropriate orthodontic treatment and has been closely followed for the earliest signs of recurrence of gingival enlargement. CONCLUSIONS: The successful therapy for gingival fibromatosis depends on correctly identifying the etiological factors and improving the impaired function and esthetic appearance through surgical intervention and adjunctive orthodontics. Maintaining treatment results depends on preservation of periodontal health.     

Clinical, radiographic, biochemical and histological findings of florid cemento-osseous dysplasia and report of a case

Florid cemento-osseous dysplasia has been described as a condition that characteristically affects the jaws of middle-aged black women. It usually manifests as multiple radiopaque cementum-like masses distributed throughout the jaws. This condition has also been classified as gigantiform cementoma, chronic sclerosing osteomyelitis, sclerosing osteitis, multiple estenosis and sclerotic cemental masses. The authors present a case of an uncomplicated florid cemento-osseous dysplasia in a 48-year-old black woman. Multiple sclerotic masses with radiolucent border in the mandible were identified radiographically. Histopathologic findings revealed formation of calcified dense sclerotic masses similar to cementum. All clinical, radiographic, biochemical and histological features were suggestive of the diagnosis of florid cemento-osseous dysplasia.     

Assessment of disk displacements of the temporomandibular joint

The aim of the present research was to evaluate disk displacements (DDs) of the temporomandibular joint (TMJ) among patients referred for magnetic resonance imaging (MRI) scans, and analyze the type and prevalence of DD, gender, age, side distribution, reciprocal clicking, presence of pain, range of mouth opening movement, and dental condition. The sample comprised 113 patients, 12-78 years old (the age average was 36.4 +/- 13.5 years), 92 females and 21 males, who underwent MRI between July 2001 and December 2002. A Signa Horizon system (GE) MRI scanner was used at a magnetic field magnitude of 1.5 T with a bilateral radiofrequency surface coil (6.5 x 6.5 cm). Twenty-three (20.4%) patients were found to be normal, whereas 90 (79.7%) presented with DD. Anterior DD (61.1%) was the most common type of articular disk displacement. Males and females were equally affected (no statistically significant difference). We did not find a statistically significant association between DD and increased age. Bilateral DD (70%) was the most common DD occurrence. We found a statistically significant association between reciprocal clicking and anterior DD with reduction. We did not find a statistically significant association between DD and pain, be it articular or facial pain, otalgia or cephalgia. We found a statistically significant association between anterior DD without reduction and mouth opening limitation. With regard to oral condition, we did not find a statistically significant association between DD and loss of teeth.     

Retention of provisional crowns cemented with eight temporary cements: comparative study

Many temporary cements are commercially available; therefore, it is necessary to indicate them for each clinical requirement with regard to the tensile strength of prosthetic retainers. Thus, the purpose of this study was to compare the retention of provisional crowns cemented with eight temporary cements, over full crown preparations with standardized mechanical principles as height, taper, and length. For that purpose, eighty human first premolars received full crown preparation with standardized height and taper. Provisional crowns were fabricated and luted with eight brands of temporary cements. Twenty four hours after cementation, the restorations were submitted to tensile strength test in a universal testing machine and the data submitted to ANOVA and Bonferroni tests. Mean tensile strength values ranged from 20.1N for Nogenol cement to 67.5N for Hydro C cement. Statistically significant difference (p<0.05) was found between Hydro C and the other groups, except for Temp Bond and Rely X Temp, which presented statistically significant difference when compared to Freegenol and Nogenol temporary cements. The crowns cemented with Hydro C cement were more retentive that than those cemented with the other cements, except for Rely X Temp and Temp Bond. The less retentive crowns were those cemented with Nogenol and Freegenol temporary cements.     

A review of the clinical management of mobile teeth

The clinical management of mobile teeth can be a perplexing problem, especially if the underlying causes for that mobility have not been properly diagnosed. In some cases, mobile teeth are retained because patients decline multidisciplinary treatment that might otherwise include strategic extractions. This article discusses the relationship between occlusion and tooth mobility with an emphasis on identifying differences between increased mobility and increasing mobility. The indications, contraindications, and basic principles of tooth splinting are also reviewed. Provisional and definitive splints are defined and described with their respective occlusal considerations. Some mobile teeth can be treated through occlusal equilibration alone (primary occlusal trauma). Whereas mobile teeth with a compromised periodontium can be stabilized with the aid of provisional and/or definitive splinting (secondary occlusal trauma). It is important to consider splint therapy, because it may not only improve the prognosis of teeth, but may actually enhance the stability of the final prosthodontic treatment. The ultimate goal of successful management of mobile teeth is to restore function and comfort by establishing a stable occlusion that promotes tooth retention and the maintenance of periodontal health.