Implants and biomaterials used in hard and soft oral tissue augmentation are very complex, but predictable to use nowadays, as the technological advances haven't skipped this field of medicine. Cases that were impossible to treat with implant retained fixed prosthesis some years ago, have become the daily practice of oral surgeons and dentists around the world. The new user-friendly products, together with simplified protocols, increased the practitioners' predictability and success rate, thus the biomaterial industry took a huge leap forward. As the biomaterial industry keeps developing continuously, making better and safer products, the surgical and prosthetic protocols evolve and change as well. On this matter, the implant placement has become safer, using digital surgical guides. Guided implant placement doesn't just allow the practitioner place the implant in the patient's bone, but, moreover, it helps him place it in the correct, 3D, prosthetic position. And, thus, guiding the future bone augmentation and regeneration as well, accordingly. So, the implant placement has shifted from bone-orientated to prosthetic-orientated, offering at the same time a better primary stability for the implants, due to the prior planning. The present clinical study aims to analyze the outcome of the digital guided protocol. Unlike the free-handed surgery, the digital guided surgery allows dentists and oral surgeons to place implants according to the future prosthetic position of the crowns, even in conditions of alveolar ridges with bone resorption. Moreover, it makes possible the "one day implant" concept, the dental technician being able to create the provisional crown/s in advance, knowing precisely the future position of the implant placement. So, at the time of the surgery, the provisional crown is also put in place, guiding the soft and hard tissue healing and also giving the patient a greater satisfaction.

Alginate impression is an elastic material included in the category of irreversible hydrocolloids. Obtaining indirect restorations cannot be separated from this material that has withstood the test of time (even if other elastic materials appeared more accurate). It is one of the most commonly used material impression and the price / quality ratio is favourable. Their chemical composition, setting time, dimensional stability and change have been the subject of exhaustive studies since their patenting in 1940. The aim of the study was to measure the dimensional change and mass loss of alginate impression. The material used was commercially XantALGIN Select Fast Set from Heraeus Kulzer's company. It was mixed according to the manufacturer. There were made 20 impressions on mandibular study models made of epoxy resin. After the preparation, these impressions were weighed and measured for 6 hours. For measuring dimensional changes there were used Stainless Hardened calliper and height measurements consisted of measuring the lateral incisor, the first premolar and the second molar, mesial - distal width and sagittal plane of the teeth (vestibular - oral). The dimensional variation used a CAD Scanner DD Argus M1 and a 3D Designer program by Exocad to process the information. For the mass of the impression, there was a slight initial decrease at first, followed by a bigger decrease of its mass at the end of the time for evaluation. The trend observed was the change in size - it was an initial expansion, followed by a regress, then another expansion (in the first hour), finally observing a decrease in the net, in the last 5 hours of the measuring. This study revealed that the mass and dimensional variations were not stable. Therefore, the best period of time to make the impression is the first half hour.