Clinical and radiographic digital imaging evaluation of a bioresorbable membrane in the treatment of periodontal bone defects

This study evaluated the use of a bioresorbable membrane (Guidor USA) for treatment of periodontal angular bone defects in eight periodontitis patients. Presurgical measurements consisted of probing depth, clinical attachment levels, and digital radiographic imaging evaluation. Full-thickness buccal and lingual flaps were elevated allowing for soft tissue debridement, scaling, and root planing. Bioresorbable membranes were placed in at least one of the periodontal defects, and controls were left without barrier placement. Clinical and radiographic results 6 months after the surgical procedure showed clinical and radiographic improvement for control and test lesions. However, sites treated with bioresorbable membranes presented a significant gain in clinical attachment and bone mass when compared to sites that had received flap surgery alone.

Comparison between 2 surgical techniques for the treatment of early-onset periodontitis

The objective of this study was to compare guided tissue regeneration (GTR) and osseous surgery (OS) in treatment of early-onset periodontitis. Six patients participated in this research, presenting 15 paired defects randomly assigned to 1 of the surgical groups. Pre-operative clinical parameters (probing depth and attachment loss) between the two groups were not significantly different. Results 1 year following surgery showed probing depth reduction (2.60 +/- 1.30 mm) and clinical attachment gain (2.20 +/- 1.42 mm) were significantly greater in the GTR group than in the osseous surgery group (P < 0.05). The gingival recession was -0.53 +/- 0.52 mm and -0.40 +/- 0.74 mm for the osseous and the guided tissue regeneration group, respectively (no significant difference, P > 0.05). Radiographic analysis by two techniques illustrated that the interproximal alveolar bone changes at the margin of the defects in the OS group were slightly decreased (-0.20 +/- 1.15; 0.26 +/- 0.74 mm) and those in the GTR group were slightly increased (0.16 +/- 0.96; 0.26 +/- 0.68 mm), but showed no significant difference (P > 0.05). The base of the GTR-treated defects showed significant increase in bone fill (1.67 +/- 0.68; 1.97 +/- 0.74 mm; P < 0.05). At a follow-up reexamination 1 year following surgery, oral hygiene and gingival conditions in both groups were at satisfactory levels and gingiva was clinically healthy throughout the entire study period, except the first 4 to 6 weeks following surgery.

Efficacy of quantitative digital subtraction radiography using radiographs exposed in a multicenter trial

Digital subtraction radiography (DSR) has been shown to be a sensitive and specific method for the detection of small bony changes in periodontitis. The purpose of this study was to perform a multicenter validation of the DSR in human subjects. Seventeen subjects were enrolled at 3 centers. Feather-edged hydroxyapatite chips (approximately 1, 7 and 10 mg) were used to simulate osseous lesions. Bilateral radiographs were taken with and without chips. Geometry was standardized using a cephalostat and the order of radiographs was determined using a randomization plan. Radiographs were subtracted, lesions isolated, and quantified at a single center without knowledge of the randomization code or location of the chips used in each subject. The overall sensitivity and specificity in detecting 1 mg changes was 87.8% and 100%, respectively. Sensitivity and specificity in detecting 7 mg and 10 mg chips was 100%. A strong linear relationship between actual lesion mass and calculated mass was observed (R2 = 0.94, slope = 0.98, p < 0.0001). No significant differences were observed by center. These data indicate that the DSR is a valid technique for the assessment of alveolar bone changes in multicenter trials.

Risk factors in dental implant failure

The goal of this study was to assess risk factors for dental implant failure. Eighty-three implants were placed in thirty patients who were followed for three years using digital subtraction radiography. The following putative risk factors for implant failure were employed in the model: age, sex, implant length, implant position, implant surface coating, smoking habit, and presence of infection. Implant failure was defined as progressive bone loss compromising the implant. We found that the presence of infection (P < 0.001) and absence of HA coating (P < 0.001) were the primary factors associated with early implant failure.

A comparison of topical ketorolac, systemic flurbiprofen, and placebo for the inhibition of bone loss in adult periodontitis

Systemic non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce alveolar bone loss in periodontitis. This study assesses the efficacy of a topical NSAID rinse, containing ketorolac tromethamine as the active agent. Adult periodontitis patients (n = 55) were studied in this 6-month randomized, double blind, parallel, placebo and positive-controlled study. Each patient had a least 3 sites at high risk for bone loss as assessed by low dose bone scan. Groups, balanced for gender, were assigned to one of three regimens: bid ketorolac rinse (0.1%) with placebo capsule; 50 mg bid flurbiprofen capsule (positive control) with placebo rinse; or bid placebo rinse and capsule. Prophylaxes were provided every 3 months. Monthly examinations assessed safety, gingival condition, and gingival crevicular fluid PGE2. Standardized radiographs were taken at baseline and at 3 and 6 months for digital subtraction radiography. A significant loss in bone height was observed during the study period in the placebo group (-0.63 +/- 0.11; P < 0.001), but not in the flurbiprofen (-0.10 +/- 0.12; P = 0.40) or ketorolac rinse (+0.20 +/- 0.11 mm; P = 0.07) groups. Nested ANOVA revealed that ketorolac and flurbiprofen groups had less bone loss (P < 0.01) and reduced gingival crevicular fluid PGE2 levels (P < 0.03) compared to placebo. ANOVA suggests (P = 0.06) that ketorolac rinse preserved more alveolar bone than systemic flurbiprofen at the dose regimens utilized. These data indicate that ketorolac rinse may be beneficial in the treatment of adult periodontitis.

Alendronate treatment of naturally-occurring periodontitis in beagle dogs

The treatment of periodontal disease has been largely directed at the microbiological etiology. The prevention of bone loss by modulating the host response to the bacteria may be a useful adjunctive method in the management of periodontitis. Alendronate, an amino bisphosphonate, may inhibit bone loss in osteolytic diseases by altering osteoclast activity. The objective of this double-blind study was to evaluate alendronate inhibition of alveolar bone loss in the naturally occurring beagle dog model of periodontitis. Sixteen 7 to 9 year old beagles with moderate-to-severe periodontitis were studied for 6 months. The dogs were stratified into two groups based on initial periodontal severity. One group received 3.0 mg/kg alendronate weekly orally and the other group received a placebo. Silk ligatures were placed on the study teeth for the first 3 months of the study to exacerbate the periodontal destruction. Clinical data were collected for attachment level, gingival index, plaque index, and mobility at baseline and one-month intervals. Intraoral radiographs were made at baseline and at 3 and 6 months. The mandibles were processed for histology at month 6. The radiographs were analyzed by digital image analysis of the subtracted images. A statistically significant difference in bone mass (P < 0.001) was observed between the alendronate and placebo groups. The bisphosphonate had no effect on the clinical parameters of gingival inflammation or plaque. A trend toward decreased attachment loss and mobility was observed in favor of the alendronate group.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of systemic flurbiprofen on bone supporting dental implants

This article describes a study of the efficacy of the non-steroidal anti-inflammatory drug flurbiprofen in maintaining alveolar bone around mandibular root-form dental implants. The preliminary results indicate that, in appropriate doses, flurbiprofen may spare bone around such implants.

Dental education at the crossroads: a report by the Institute of Medicine

Today's dental schools confront an environment in higher education and health care that promises less stable financing and, thus, more uncertainty for faculty, students, researchers and administrators. A new report from the Institute of Medicine underscores the need for changes in dental education to prepare for a future that will in many important ways be quite different from the past.

Research, technology transfer, and dentistry

The periodontal discipline illustrates the need for dentists to be doctors specializing in oral medicine. Research findings are tending toward more complex and possibly lengthy treatment with drugs and/or growth factors, necessitating a curriculum with more emphasis on pharmacology, medical management, critical review of clinical trial results, and evaluation of risk-benefit ratios.

A comparison of the diagnostic advantages of panoramic radiography and computed tomography scanning for placement of root form dental implants

This study evaluated the advantages of computed tomography (CT) in comparison to routine panoramic radiography for dental implant treatment planning. An in vitro validation study was performed to assess the accuracy of CT and panoramic radiography film images for measurement of anatomic structures and distances between anatomic structures. After correcting by a standard 25% magnification on the panoramic images, a significant difference in measurements was found between the CT and panoramic radiography images. Ten subjects requiring implants in compromised ridges were treatment planned with either CT and panoramic radiographs or panoramic radiographs alone. The ideal implant length was determined at surgery with direct digital radiography. The dentists were significantly more confident using CT and panoramic images than panoramic radiographs alone. Implant length treatment planned with panoramic radiography alone underestimated length significantly compared with the implant length determined to be ideal during surgery, whereas treatment planning with CT and panoramic radiography demonstrated no significant difference. The data indicate the CT may be of value in treatment planning for dental implants, especially when gaining maximum length is of critical importance.

An adaptable head retention and alignment device for computed tomography scanning of Macaca mulatta

An adaptable retention device has been developed for the purpose of holding and aligning the head of a sedated primate subject during computed tomography (CT) scan procedures. The device is used to obtain a close reproduction of CT scan studies at a time before and after dental implant placement in the mandibles of nine subjects. Geometric and material properties are extracted from these studies for the purpose of developing finite elements computer models. The device is constructed of low-density acrylic and consists of a horizontal base to which lateral supports are affixed. The device is placed on the CT table and axially aligned with the scan beam. Repeatable, calibrated CT studies of primate implant subjects were possible using the head holding device.

Prevention of periodontal diseases in adults: strategies for the future

Gingivitis and periodontitis are the most prevalent periodontal diseases in adults. Gingivitis is characterized by inflammation of the gingiva without loss of connective tissue attachment to the teeth while periodontitis results in loss of attachment and alveolar bone and may lead to tooth loss. Gingivitis is highly prevalent in adults in the United States, and up to 70% of adults have at least mild periodontitis. In only a small proportion of adults (< 15%) does periodontitis progress to severe disease. The etiology of periodontal disease is infection with pathogenic dental plaque bacteria in a susceptible host. Strategies for preventing periodontal diseases therefore may intervene at the level of the initiation of the inflammatory process, or by preventing the progression of bone and attachment loss in periodontitis. Improved mechanical and chemical plaque control as well as improved restorative materials to facilitate plaque removal continue to enhance the patient's ability to control the plaque bacteria. Strategies to target prevention to the patients who need it most include risk factor assessment, new diagnostic methods, and further elucidation of the natural history of periodontal disease. Further study of the etiology and pathophysiology of periodontitis will aid in the prevention of further destruction through targeted use of local and systemic antibiotics and well as drugs to aid in the host response. Ultimately research may yield multivalent vaccines to be used in high-risk patients.

Current concepts in periodontal disease testing

Tests for periodontal disease fall into four categories. The test may identify putative periodontopathic plaque bacteria, the susceptible host, metabolic changes associated with inflammation, tissue damage or death or anatomic changes including periodontal probing and radiographs. The current understanding of tests for periodontal disease is reviewed within a framework for understanding the rationale for such tests.

Longitudinal evaluation of elastase as a marker for the progression of periodontitis

To determine whether elastase levels in gingival crevicular fluid (GCF) could serve as a marker for the progression of periodontitis, we monitored GCF elastase and periodontal status in selected sites in 32 periodontally healthy volunteers and 31 periodontitis patients at intervals over a 6-month period. Clinical measurements included plaque index, gingival index, bleeding on probing, suppuration, probing depth, clinical attachment level, and relative attachment level measured with an automated disk probe. GCF elastase, detected by reaction with a fluorescent substrate, was assessed visually against fluorescence standards and quantitatively with a fluorometer. Bone loss was detected by subtraction radiography of standardized vertical bite-wing radiographs at baseline and 6 months. Mean visual elastase scores (VES) and quantitative elastase measurements were significantly higher (P < 0.001) in sites from periodontitis patients than in sites from healthy volunteers. When bone loss was used as the criterion for disease progression, significantly higher (P < 0.001) visual and quantitative GCF elastase levels were found at progressing sites than in nonprogressing sites in the periodontitis patients. The odds ratios (OR) for the event of developing bone loss with positive 4-minute and 8-minute VES tests were 4.2 (P < 0.001) and 7.4 (P < 0.001), respectively. When corrected for the tendency of progressing sites to be clustered within a subpopulation of patients, the OR for developing bone loss with the 4-minute and 8-minute VES tests were 3.1 (P < 0.007) and 4.9 (P < 0.001), respectively. These data indicate that sites with high levels of elastase are at significantly greater risk for progressive bone loss as assessed by digital subtraction radiography.

Bone loss in the oral cavity

Bone loss in the oral cavity may occur due to many causes, including infection, systemic or local alterations in the host response, or multifactorial causes. The purpose of this article is to review our present understanding of the major causes of oral bone loss in adults, with special emphasis on two major oral diseases: periodontitis and residual ridge resorption. Periodontitis is characterized by resorption of the alveolar bone as well as loss of the soft tissue attachment to the tooth. Progressive periodontitis will result in continued alveolar bone loss and may result in tooth mobility, abscesses, and ultimately tooth loss. Although the reported prevalence may vary according to the epidemiologic study design, the 1985 National Survey of Oral Health of United States Adults indicated that 94% of female senior citizens examined demonstrated at least one site with at least 2 mm loss of attachment. Resorption of alveolar bone that occurs following tooth extraction is termed residual ridge resorption. In many cases, the denture will loosen because of the inability of the resorbed ridge to stabilize the prosthesis. In the most severe cases, the denture may impinge on the exposed mandibular nerve, resulting in pain or total inability to tolerate the prostheses. Although clear statistics on the prevalence of residual ridge resorption are not available, this boss loss may result in the need for new dentures to replace ill-fitting prostheses.

Effects of nonsteroidal antiinflammatory drugs on bone loss in chronic inflammatory disease

Several controlled clinical trials have indicated that nonsteroidal antiinflammatory drugs may slow alveolar bone loss in periodontitis. Demonstration of this efficacy is dependent on the development of accurate, sensitive, and specific quantitative methods for the assessment of bony change, such as digital subtraction radiography. Further studies of such methodologies are required to more fully investigate the effect of nonsteroidal antiinflammatory drugs in rheumatoid arthritis.

Systemic osteoporosis and oral bone loss: evidence shows increased risk factors

Aging is associated with a loss of bone mass and an increased risk of oral and systemic bone loss. Systemic osteoporosis can result in bone fractures, especially of the spine and hip, with the characteristic spinal curvature and loss of height often seen in osteoporotic postmenopausal women. Loss of teeth and ridge resorption can occur in the mouth.

Efficacy of meclofenamate sodium (Meclomen) in the treatment of rapidly progressive periodontitis

This 6-month, double-blind, controlled clinical trial determined the efficacy of the non-steroidal anti-inflammatory drug, meclofenamate sodium (Meclomen), as an adjunct to scaling and root planing in the treatment of rapidly progressive periodontitis (RPP). 22 subjects (7 male, 15 female) aged 36.5 +/- 7.88 years with RPP and disease-active sites as determined by pretreatment bone scan had standardized radiographs at baseline and 6 months, and clinical measurements at baseline, 3 and 6 months. Following full-mouth scaling and root planing, subjects were randomly assigned to either a placebo, 50 or 100 mg meclofenamate sodium bid group. Bone change over the 6-month period as assessed by subtraction radiography was the primary efficacy determinant. Specialized software was used to isolate the lesion from the subtraction image and to measure bone change along the root surface. ANOVA using the subject as the unit of analysis revealed a significant dose response (p < 0.001) with the placebo group having a mean bone loss of 0.42 +/- 0.06 mm and the low and high dose groups having mean bone gains of 0.07 +/- 0.05 and 0.20 +/- 0.07 mm, respectively. These findings indicate that meclofenamate sodium may be a useful adjunct in the treatment of rapidly progressive periodontitis.

Digital subtraction radiography

Subtraction radiography offers greater visualization of radiographic changes between a pair of radiographs by subtracting out the unchanging background distractions. Originally, subtraction was achieved by using positive and negative prints in angiography. The advent of digital imaging devices has led to validation of quantitative measurements from digital subtraction images. As well, computer software manipulations have allowed for more flexibility in the clinical application of subtraction imaging. The clinical application of digital subtraction radiography is discussed along with clinical cases.

Application of digital radiography to implantology

Modern digital radiographic techniques can aid the clinician in planning dental implant selection and placement before and during surgery, a well as in the long term assessment of periimplant bone support. Implant treatment planning can be facilitated using computed tomography on film-based motion tomography. During surgery, direct digital radiography allows the clinician to visualize the relationship of the osteotomy sit to important anatomic structures such as the mandibular nerve. Following placement, digital subtraction radiography permits detection of osseous changes too small to be seen by eye with an accuracy approaching 95%. Such sensitivity and specificity encourages early evaluation and, if necessary, intervention on behalf of the ailing implant.

Digital subtraction radiography for longitudinal assessment of peri-implant bone change: method and validation

The purpose of this paper is to present a digital subtraction technique for the assessment of peri-implant bone change over time in vivo. Digital subtraction radiography may be used to detect areas of bony change that have occurred between radiographic examinations, and image processing algorithms have been developed which can relate the magnitude of the change on the subtraction image to a reference wedge, thereby allowing calculation of the mass of the lesion. This manuscript will present two algorithms for the assessment of osseous change. The method was validated in monkeys by means of small bony chips placed intra-orally prior to the first radiograph. The chips were removed, a second radiograph taken, and the images subtracted. Each algorithm was used to isolate the lesion and calculate change in bone mass. Overall, there was excellent correlation between the calculated lesion mass (in milligrams) and actual lesion mass (r2 > 0.9). The utility of the method was demonstrated by comparison of the results of subtraction radiography in successful implants and in implants that did not integrate during the healing phase.