Undesirable dental hard tissue effects hypothetically linked to orthodontics - a microscopic study.

Like any other medical intervention, the orthodontic treatment may have, besides the positive effects, also unwanted secondary consequences. The aim of this study was to evaluate the changes present in dental hard tissue associated with orthodontic treatment. The stereo-microscopic ex vivo analysis was performed on two sets of maxillary first premolars undergoing orthodontic treatment for a long period of time (12 and 23 months); five teeth with other clinical situations were used as controls. By analyzing the teeth undergoing orthodontics, enamel color alterations were mainly found adjacent to the bracket, more pronounced in the gingival area, suggesting the need for a correct oral hygiene around it. Roughness was higher on the enamel surface corresponding to the bracket's base, aspect linked to the resign impregnation during bonding procedures. At the apical part, changes regarding contour, appearance and surface roughness were noticed. These modifications were suggestive for the presence of apical root resorption. The severity of root resorption was not correlated with the duration of treatment. In conclusion, through microscopic analysis changes that may be associated with orthodontic treatment have been observed in both crown and apical level.

Aspects of oral morphology as decision factors in mini-implant supported overdenture.

AIM: Evaluation of some morphological oral aspects perceived as decision factors in complete edentulism treatment by mini-implants overdenture. PATIENTS, MATERIAL AND METHODS: An observational study was conducted on a sample of 24 patients (average age of 61 years), through clinical and imagistic methods. The variables taken into consideration were: age, gender, alveolar mucosa status, bone offer, mini-implants characteristics, insertion torque and loading type. RESULTS: 117 mini-implants were applied, 59% to the lower jaw and 41% to the upper jaw. On average, there were inserted 5.33 implants to maxilla and 4.6 to mandible. Fifty-seven percent of implants were applied in the interforaminal area. The implants used had 10 mm (28.2%) and 13 mm (71.8%). In only 41% patients, the ridge width was higher than 5 mm (value necessary for conventional implant application). Diameters of implant used were: 1.8 mm (2.56%), 2.1 mm (25.64%) and 2.4 mm (71.8%). Smaller diameters were used in mandible. Only in 16.67% of patients was possible the transmucosal insertion. Bone density was D2 and D3 for men, and D3 and D4 for women. Immediate loading was achieved in 20.5% patients. CONCLUSIONS: Mini-implant supported overdenture can be an alternative to conventional denture and conventional implant overdenture. Its advantages derives from implants' characteristics (smaller diameter, variable length, O-ring retention system), which adapts better to the particular edentulous conditions. Insertion technique implies less surgical trauma. Choosing implants' size, number, topography, and the loading method have a great variety, depending on anatomical feature (bone offer, mucosa and relationship with the nearby anatomical structures), functional features and patients' wishes.