Technetium 99m-MDP scintigraphy of patients undergoing implant prosthetic procedures: a follow-up study

Impact of bisphosphonate drugs on dental implant healing and peri-implant hard and soft tissues: a systematic review

Objective

Implantology represents the gold standard for oral rehabilitation, unfortunately, often, despite there are no local contraindications to this type of rehabilitation, there are uncertainties regarding the general health of our patients. Many patients nowadays take bisphosphonate drugs, often without first seeking advice from an oral surgeon or a dentist. The purpose of this review is precisely to highlight any contraindications to this type of treatment reported in the literature, in patients who take or have taken bisphosphonate drugs.

Methods

For this study the scientific information sources were consulted using as search terms “(“bisphosphonate AND “dental implant”)”, obtaining 312 results, these were subsequently skimmed according to the inclusion and exclusion criteria, and further evaluated their relevance to the study and the presence of requested outcomes.

Results

Only 9 manuscripts (RCTs, Multicentric studies and Clinical Trials) were included in this review, as they respected the parameters of this review, they were analyzed and it was possible to draw important results from them. Surely from this study it is understood that the use of bisphosphonate drugs does not represent an absolute contraindication to implant therapy, it is evident how adequate pharmacological prophylaxis, and an adequate protocol reduce the risks regarding implant failures. Furthermore, the values of marginal bone loss over time seem, even if not statistically significant, to be better in implant rehabilitation with bisphosphonate drugs association. Only a few molecules like risedronate, or corticosteroids, or some conditions like smoking or diabetes have shown a high risk of surgical failure.

Conclusion

Although this study considered different studies for a total of 378 patients and at least 1687 different dental implants, showing better results in some cases for dental implant therapy in cases of bisphosphonate intake, further clinical, randomized and multicentric studies are needed, with longer follow-ups, to fully clarify this situation which often negatively affects the quality of life of our patients and places clinicians in the face of doubts.

Visual Pattern and Serial Quantitation of 18F-Sodium Fluoride PET/CT in Asymptomatic Patients After Hip and Knee Arthroplasty

PURPOSE

We investigated the visual tracer distribution pattern and serial changes in uptake ratio in different anatomical zones during the natural postoperative course in order to establish a reference for evaluation of patients with complications.

METHODS

A total of 36 patients without symptoms after hip or knee arthroplasty were grouped according to the interval between surgery and the scan. The serial changes in SUVmean in each periprosthetic zone were quantified using the volume of interest isocontour method. Images were classified according to the uptake distribution pattern. The uptake ratios in the postoperative period groups were then compared using the Kruskal-Wallis test. The correlation between uptake ratio and postoperative period was then determined.

RESULTS

Tracer distribution patterns in hip prostheses were classified into three types and the patterns in knee prostheses into five types. In hip prostheses, intense osteoblastic activity was observed during 3-6 months and then declined in most patients, but showed a slight increase over 15-25 months in 5-10 % of patients. The correlation coefficients varied among the zones. Significant differences in uptake ratios among the period groups was found for all zones, except zone 8. Porous coated areas showed higher uptake than uncoated areas only for the period the 3-6 months. In knee prostheses, uptake ratios showed a curvilinear pattern, increasing from 3-6 to 8-15 months and declining later. The uptake ratios were different among the period groups. Every zone showed a positive correlation from 3-6 to 8-15 months, and negative correlations from 8-15 to 22-25 months.

CONCLUSIONS

This is the first ¹⁸F-sodium fluoride PET/CT study investigating the stability of implants and sets a reference for evaluation of patients with complications.

Role of single photon emission computerised tomography in evaluating osseointegration of indigenous DRDO implants: An in vivo study

BACKGROUND

A study of first indigenous titanium dental implant developed by DRDO was undertaken at INMAS, Delhi. The aim was to establish the time taken for osseointegration, along with objectives to define the time of implant loading and compare the osseointegration of indigenous dental implants with already established dental implant systems.

METHODS

21 subjects rehabilitated using 39 indigenous dental implants were evaluated by bone SPECT before implantation and at regular intervals towards establishing the aim and objectives.

RESULTS

The rise followed by fall in Osteoblastic activity indicates the postoperative physiologic changes, which peaked at 2 weeks (mean) post-implantation and falls off to pre-implantation levels in 12 weeks (mean) indicating completion of osseointegration, healing and time of loading.

CONCLUSION

It can be summarized that the Osteoblastic activity of indigenous dental implants completes within three months, which can be taken as the time required for complete healing/osseointegration and loading the implants. On comparison with the available data of already established implants the figures appear similar, indicating indigenous implants to be similar in biologic behaviour.

Role of nuclear medicine imaging in recognizing different causes of osteonecrosis of the jaw

The incidence of osteonecrosis of the jaw (ONJ) among patients with cancer and metastatic bone disease being treated with bisphosphonates is as high as 10%, which dictates that an understanding of the risk factors, preventative measures, means of early diagnosis, and treatment is critical. Despite ONJ occurring in the clinical setting of intravenous bisphosphonates, there are other causes associated with higher risk of ONJ, such as multiple dental extractions. Overall, it is important for imaging health care professionals to recognize, describe, and understand ONJ to help minimize biopsies and allow proper treatment to begin as soon as possible.

Implications of three-phase bone scintigraphy for the diagnosis of bisphosphonate-related osteonecrosis of the jaw

PURPOSE

Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) is a well-known serious complication of BP treatment. This study was undertaken to evaluate the diagnostic usefulness of three-phase bone scintigraphy in patients with BRONJ.

METHODS

Forty-one patients (48 lesions) with clinically proven BRONJ (2 males, 39 females, age 74.3 ± 6.7 years) underwent Tc-99 m HDP bone scintigraphy. Visual interpretation and semiquantitative analysis of uptakes using lesion-to-contralateral uptake ratios during the blood pool phase (BUR) and during the osseous phase (OUR) were performed, and relations were sought between these and various clinical parameters.

RESULTS

Three-phase bone scintigraphy showed increased perfusion and blood pooling in 21 (63.6 %) and 27 (81.8 %) of 33 lesions, respectively. The osseous phase was positive for 45 (93.8 %) of the 48 lesions. Of the four inflammatory clinical parameters of BRONJ [pus discharge, pain, swelling, and erythrocyte sedimentation rate (ESR)], patients with three or more parameters had more positive findings in vascular and blood pool phase images (p = 0.033, p = 0.027). By semiquantitative analysis, patients with a positive ESR had statistically higher BUR and OUR (both p < 0.001). Higher stage BRONJ lesions had higher OUR than lower stage lesions (p = 0.003). In addition, bone scintigraphy revealed three clinically covert BRONJ lesions without bone exposure, and four patients were up-staged based on bone scintigraphy.

CONCLUSIONS

Bone scintigraphy provides a relatively sensitive means of detecting BRONJ, so it was helpful for accurate BRONJ staging. Furthermore, increased uptakes in vascular and blood pool phases of three-phase bone scintigraphy were related to the inflammatory activity of BRONJ.

Evaluation of osteoblastic activity around dental implants using bone scintigraphy

OBJECTIVES

The aim of this study was to evaluate the osteoblastic activity around delay-loaded intraosseous dental implants using nuclear medicine imaging techniques.

MATERIAL AND METHODS

Seven totally edentulous patients (two females and five males, between 48 and 57 years of age) were included in the study. Two implants were inserted into mandibular canine regions and removable prostheses were produced after 3 months. Whole-body bone scintigraphies with 20 mCi technetium 99m labelled methylene diphosphonate were taken from the patients before implant insertion, 3 months after implant placement just before the prostheses were made and 1 year after implant placement. Standardized count/pixel (SC/P) rates were calculated for each patient. Preimplantation SC/P values were compared with the 3- and 12-month values. Three-month values were compared with the 12-month values as well.

RESULTS

SC/P rates in the third month were significantly higher (P<0.05) than preoperative values and the SC/P rates of the 12th month were significantly lower (P<0.05) than 3-month values. The SC/P rates of the 12th month were relatively higher than first scintigraphies but the difference was insignificant (P>0.05).

CONCLUSIONS

Within the limitations of this study, in which delayed loading was applied, we showed that osteoblastic activity persisted more in delay loaded implants than immediate and early loading. After 1 year, there was no cellular activity around two implants and this implied that two implants were sufficient for a total prosthesis.

Randomized clinical trials in implant therapy: relationships among methodological, statistical, clinical, paratextual features and number of citations

OBJECTIVES

The aim of the present study was to investigate the relationships among reported methodological, statistical, clinical and paratextual variables of randomized clinical trials (RCTs) in implant therapy, and their influence on subsequent research.

MATERIALS AND METHODS

The material consisted of the RCTs in implant therapy published through the end of the year 2000. Methodological, statistical, clinical and paratextual features of the articles were assessed and recorded. The perceived clinical relevance was subjectively evaluated by an experienced clinician on anonymous abstracts. The impact on research was measured by the number of citations found in the Science Citation Index. A new statistical technique (Structural learning of Bayesian Networks) was used to assess the relationships among the considered variables.

RESULTS

Descriptive statistics revealed that the reported methodology and statistics of RCTs in implant therapy were defective. Follow-up of the studies was generally short. The perceived clinical relevance appeared to be associated with the objectives of the studies and with the number of published images in the original articles. The impact on research was related to the nationality of the involved institutions and to the number of published images.

CONCLUSIONS

RCTs in implant therapy (until 2000) show important methodological and statistical flaws and may not be appropriate for guiding clinicians in their practice. The methodological and statistical quality of the studies did not appear to affect their impact on practice and research. Bayesian Networks suggest new and unexpected relationships among the methodological, statistical, clinical and paratextual features of RCTs.

An In Vitro Comparative Study of Bioglass and Biologically Derived Hydroxyapatite with Bone Scintigraphy (BS) Method

Four rabbits received human derived HA to their left tibias. After 16 weeks bioglass was implanted to their right tibias. After other 16 weeks bone scintigraphies were taken with 99mTc- MDP. Three phase bone scan images showed no evidence of inflammation and superior vascularization rates at implantation sites. In this study, bioglass demonstrated higher uptake of 99mTc-MDP comparing to HA, suggesting a higher vascularization rate and better osseointegration.

Dental diseases and radionuclide imaging of the jaws

The aim of this study was to compare the results of radionuclide bone scans of the jaws with data obtained at the nuclear medicine department from a brief and feasible dental history, taking special account of cases with a positive scan and no recent dental events. Ninety-eight patients undergoing radionuclide bone scan as part of their diagnosis in non-dental, oncological and non-oncological diseases were imaged with 99mTc-labelled oxidronate. Superior and inferior halves of the mandible and maxilla (392 quadrants) were regarded as normal or having an abnormally high uptake. A recent (1 year) dental history was also obtained through a brief questionnaire and data were referred to each quadrant of the jaws. The association between the bone scan and dental disease was assessed by means of the chi-squared test. The overall results of scintigraphy and history coincided in 66 patients (46 with abnormal and 20 with normal findings; P = 0.002). Twenty-five patients had a positive scintigram without any known dental disorder. Results of scintigraphy and history coincided in 254 quadrants (78 with abnormal and 176 with normal findings; P < 0.001). Eighty-three quadrants had hot spots in the scintigram without any known dental lesion. It can be concluded that abnormal jaw scintigrams are frequent in patients without known dental disease, and this may indicate silent osteoblastic activity. These observations should be reported to the dentist for several reasons. First, they may reveal asymptomatic dental lesions. Second, the use of oral prostheses and implants is increasing and they require the support of healthy alveolar bone.

Bisphosphonates and periodontics: potential applications for regulation of bone mass in the periodontium and other therapeutic/diagnostic uses

Bisphosphonates are widely utilized in the management of systemic metabolic bone disease due to their ability to inhibit bone resorption. Recently, new uses of this unique class of pharmacological agents have been suggested. Given their known affinity to bone and their ability to increase osteoblastic differentiation and inhibit osteoclast recruitment and activity, there exists a possible use for bisphosphonates in the diagnosis and management of periodontal diseases. These bone-specific properties could also provide an interesting management strategy to stimulate osteogenesis in conjunction with regenerative materials around osseous defects and may also result in the promotion of bone formation around endosseous implants. The objective of this article is to review the scientific evidence regarding the potential applications of bisphosphonate drugs in the therapeutic management of periodontal diseases. Moreover, the mechanism of action and the pharmacology of these drugs will be reviewed. Finally, the potential role of bisphosphonates regarding their potential to accelerate bone formation, in addition to their usual uses for inhibition of bone resorption, is discussed.