ABSTRACT
BACKGROUND: Success of an implant depends on its placement in the bone and how well the stress and strain are distributed to the surrounding structures when occlusal force is applied to it. The size and shape of the implant plays an important role is the formation and distribution of stress and strains in the periodontium. Von Mises stresses and micromovements need to be evaluated while placing implants in D4 bone quality regions for a higher success rate. AIM: To evaluate the peri-implant Von Mises stresses, strains, and micromovements distribution in D4 bone quality around ultra-short implants of 5 mm length with varying diameters of 4 mm, 5 mm, and 6 mm. MATERIALS AND METHODS: The finite element method was employed to make models replacing maxillary molars in D4 type bone that was missing. Implants that could be classified as ultrashort (5 mm) were used. These implants were of varying diameters of 4, 5, and 6 mm. In each model, the implant was subjected to a force of 100 N and analyzed. The force was applied in an oblique (45 degrees) and vertical direction (90°) to the long axis of the tooth. The models were made such that they simulated cortical and cancellous anisotropic properties of the bone. The models were then analyzed using the program ANSYS workbench version 12.1. RESULTS: When all the three diameters were compared wide diameter, i.e., 6 mm threads had the least values of peri-implant von Mises stresses, strains, and micro-movements around them. When thread shapes were taken into consideration square micro thread created the most favorable stress parameters around them with minimum values of stress, strains, and micromovements. CONCLUSION: Ultrashort implants combined with a wide diameter and platform switched can be used in atrophic ridges or when there is a need for extensive surgery to prepare the implant site.
ABSTRACT
Aim: Aim of this review was to present a comprehensive outline of the use of hard tissue lasers in Periodontics with respect to non-surgical periodontal treatment. Materials and method: Electronic databases of PubMed and Cochrane Library were searched from 1992 to 2018. 18 clinical studies were evaluated after the inclusion, exclusion criteria. Results: It was deduced that Er:YAG laser is a feasible option for non-surgical periodontal therapy if proper parameters are followed i.e. the energy in the range of 140-160 mJ and frequency of 10 Hz. None of the studies favoured the use of Nd:YAG and CO2 laser because of their prospective adverse effects. Conclusion: It can be concluded that Er:YAG laser application in non-surgical periodontal therapy is valuable. In combination with mechanical debridement, the results are similar or better with significant gains in clinical attachment level as compared to other various lasers. It is an excellent alternative to control the proliferation of micro-organisms. Nd:YAP, diode and other low power lasers can be used but with caution since they offer no additional advantage over conventional treatment modalities.
Subject(s)
Chronic Periodontitis/therapy , Lasers, Solid-State/therapeutic use , Chronic Periodontitis/radiotherapy , Humans , Periodontal Attachment Loss/therapyABSTRACT
The idea of absolute anchorage has always been an elusive goal for clinicians. Orthodontic mini-implants or temporary anchorage devices allow tooth movements previously thought to be impossible or difficult. Although extensive literature exists on use of temporary anchorage devices, their failures have been hardly focused upon, especially implant fracture. The following case report describes successful management of fractured orthodontic mini-implant.
