The effect of strontium chloride on human periodontal ligament stem cells.

The complete repair of periodontal structures remains an exciting challenge that prompts researchers to develop new treatments to restore the periodontium. Recent research has suggested strontium ion to be an attractive candidate to improve osteogenic activity. In this study, we have isolated a clonal finite cell line derived from human periodontal ligament (PDL) in order to assess whether and in which way different doses of SrCl2 (from 0.5 to 500 µg/ml) can influence both the proliferation and the mineralization process, for future application in oral diseases. PDL cells were cloned by dilution plating technique and characterized by FACS. Cell proliferation analysis and mineralization were performed by [3H]-thymidine incorporation and spectrofluorometric assay. Results have evidenced that the higher SrCl2 concentrations tested, from 25 to 500 µg/ml, have increased the proliferation activity after only 24 h of treatment. Interestingly, the same higher concentrations have decreased the mineralization, which was conversely increased by the lower ones, from 0.5 to 10 µg/ml. Our findings suggest the possible use of SrCl2 in appropriate delivery systems that release, at different time points, the specific dose, depending on the biological response that we want to induce on periodontal ligament stem cells, providing a more efficient periodontal regeneration.

Periodontal disease in Paget's disease of bone.

A 59-year-old man suffering from Paget's disease of bone and periodontal disease was examined in anticipation of bisphosphonate treatment. The previous therapy with clodronate resulted ineffective and markers of bone turnover were markedly elevated. Periodontal disease was correctly approached and treated with an excellent outcome. 5 mg zoledronate iv infusion induced a remarkable reduction of bone markers which persisted on time within the normal range. After zoledronate treatment no signs of osteonecrosis of the jaw (ONJ) were observed. A correct management of periodontal disease is mandatory in pagetic patients on bisphosphonate treatment.

Implant placement in combination with sinus membrane elevation without biomaterials: a 1-year study on 15 patients.

BACKGROUND: Membrane elevation in combination with implant placement without biomaterials is a rather new technique proposed for sinus lifting. PURPOSE: This study assessed the clinical outcome of such technique during the first year of loading. MATERIAL AND METHODS: Fifteen patients with a mean residual bone height of 6.2 mm were consecutively recruited for sinus lifting. After opening a replaceable bone window, the membrane was dissected from the sinus walls. A total of 28 implants were placed in the residual crest and they kept the membrane lifted upwards. After window repositioning, the flap was sutured. A 6-month healing period was allowed. Patients were re-examined after 12 months of loading. RESULTS: All the implants survived at the end of the follow-up. The 5.5 mm mean bone reformation was significantly lower than the 8.2 mm mean membrane lift achieved after implant placement. Regeneration at the distal surface of the most posterior implants was significantly less than at other aspects. The height of membrane lift was not correlated with the amount of regenerated bone. CONCLUSIONS: All of the 28 implants placed in combination with sinus membrane elevation were stable during the first year of loading. No extra costs for biomaterial or morbidity for bone harvesting were necessary.

Bone regeneration in dentistry.

The edentulism of the jaws and the periodontal disease represent conditions that frequently leads to disruption of the alveolar bone. The loss of the tooth and of its bone of support lead to the creation of crestal defects or situation of maxillary atrophy. The restoration of a functional condition involves the use of endosseous implants who require adequate bone volume, to deal with the masticatory load. In such situations the bone need to be regenerated, taking advantage of the biological principles of osteogenesis, osteoinduction and osteoconduction. Several techniques combine these principles with different results, due to the condition of the bone base on which we operate changes, the surgical technique that we use, and finally for the bone metabolic conditions of the patient who can be in a state of systemic osteopenia or osteoporosis; these can also affect the result of jaw bone reconstruction.