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S i n u s l i f t a n d M g-e H A/c o l l a g e n-b a s e d s c a f f o l d Introduction Sinus floor augmentation has recently become a widely accepted surgical procedure to improve the amount of bone volume before implant placement. Although the use of autogenous bone appears to be the gold standard,1, 2 much attention has been paid to the use of bone substitutes. After the har- vesting procedure, donor site morbidity has to be taken into consideration.3 Additional disadvan- tages for autografts are the limited availability and the tendency to resorb.4 In order to overcome these limitations, several biomaterials have been evalu- ated in experimental and clinical studies, such as demineralized freeze-dried bone allograft,5 bovine bone matrix,4 composite bone graft including platelet-rich plasma,6 resorbable and nonresorb- able hydroxyapatite7, 8 and beta-tricalcium phos- phate.9 In particular, bioceramics based on calcium phosphate are widely used owing to their biocom- patibility, absence of immunogenic factors and osteoconductivity; although, the high temperature during the sintering process could negatively influ- ence osteoconductivity and resorption time.10 New hydroxyapatites enriched with magnesium (Mg-e HAs) have recently been introduced on the market. Mg-e HA has been demonstrated to allow com- plete healing of the tissue around a graft and undergoes almost complete resorption already after 1 year.11 Despite its high predictability, the more recent literature has highlighted possible complications after this procedure.12 The main complication is membrane perforation, mostly during implant insertion. Mg-e HA/collagen-based scaffolds have been successfully used for sinus augmentation procedures, demonstrating bone formation after 6 months already.13 Owing to its properties, this material might be suitable to pro- tect the sinus membrane from eventual perfora- tion during implant insertion. The present preliminary prospective study was designed to evaluate clinically and radiologically implant restorations 12 months after prosthetic loading in severely resorbed maxillae requiring 1-stage sinus lift surgery. The graft used was an Mg-e HA and Mg-e HA/collagen- based scaffold with a porous 3-D structure and was used to pre- vent Schneiderian membrane perforation. Materials and methods S t u d y d e s i g n a n d p a t i e n t s e l e c t i o n One dental center consecutively recruited 13 patients scheduled for implant-supported restoration in the posterior maxilla with a sinus augmentation procedure. A total of 26 wide- diameter implants with a rough surface over their entire length were inserted in extremely resorbed posterior maxillae. The present study was performed following the principles outlined in the Declaration of Helsinki of 1975, as revised in 2013, on experimentation involving human subjects. All of the patients were in general good health. They were informed about the pro- cedure and required to sign a consent form. They were followed for a period of 12 months after prosthetic rehabilitation. The principal inclusion criterion was a residual bone crest (distance between the sinus floor and bone crest) ranging between 1 and 3 mm in height and allowing wide-diameter implant insertion. Additional inclusion and exclusion criteria are summarized below: Subject inclusion criteria: – Need for fixed implant-supported prosthesis in the posterior maxilla. – Aged > 18 years. – No relevant medical conditions. – Nonsmoker or smoked ≤ 10 cigarettes/day (pipe or cigar smokers were excluded). – Full-mouth plaque score and full-mouth bleeding score of ≤ 25%. Study site inclusion criteria: – Native bone height of 1–3 mm in the sinus zone. Subject and site exclusion criteria: – Acute infection of the Schneiderian membrane or chronic sinusitis. – Allergies involving the respiratory system. – A history of bisphosphonate therapy. – Uncontrolled diabetes (glycated hemoglobin A1c > 6%, glycemic level > 110 mg/dL). P r e o p e r a t i v e a n d p o s t o p e r a t i v e m e d i c a t i o n The patients underwent a preoperative digital panoramic radiograph, subsequently used as baseline. A cone beam computed tomography scan was also required to investigate antral anat- omy (Fig. 1). One week before the surgical pro- cedure, full-mouth professional prophylaxis was performed. The patients were instructed to use 1 g of penicillin clavulanate 1 day prior to surgery and continue with 2 g per day for 6 days. Just before surgery, the patients underwent a 5-min mouth rinse with 0.2% chlorhexidine gluconate. Journal of Oral Science & Rehabilitation Volume 4 | Issue 1/2018 09