Mucosal and radiographic aspects during the healing period of implants placed in a one-stage procedure

Purpose: The aim of this prospective clinical trial was to compare peri-implant clinical and radiographic parameters following the placement of nonsubmerged two- and one-stage implants. Materials and Methods: Patients were randomly assigned to the IMZ group (20 patients receiving two IMZ two-stage implants in a one-stage procedure) or ITI group (20 patients receiving two ITI implants in the conventional one-stage procedure). The healing period was defined as an 18-week unloaded osseointegration period and a 1-year functional period during which maturation of bone took place. Twelve weeks after implant placement, fabrication of an overdenture with a bar-clip attachment system was started; it was placed at 18 weeks. Results: None of the implants were lost during the osseointegration period; one IMZ implant was removed during the functional period because of mobility. There was no significant difference in Gingival Index between the two groups at all evaluation periods. The mean bone loss during the functional period was 0.6 mm in both groups. A high number of healing abutments loosened in the IMZ group. Conclusion: Clinical and radiographic parameters of two-stage implants placed in a one-stage procedure and one-stage implants are comparable during the healing period. Healing abutments of the IMZ implant system loosen easily

Mandibular overdentures supported by two or four endosteal implants - A prospective, comparative study

The aim of this prospective study was to evaluate the effect of the number of implants supporting a mandibular overdenture on the condition of the peri-implant tissues. Sixty edentulous patients (Cawood class V-VI) participated in this study. After randomization, thirty patients were treated with an overdenture supported by two IMZ implants (group A) and thirty patients with an overdenture on four IMZ implants (group B). The implants were inserted in the anterior region of the mandible. After three months overdentures were constructed, supported by round bar and clip attachments. A standardized clinical and radiographic evaluation was performed 0, 6 and 12 months after insertion of the denture. One implant was lost (group A) during the healing period. There were no significant differences with regard to any of the studied clinical or radiographic parameters of the peri-implant tissues, neither were significant differences found between the lateral and central implants in group B. None of the patients reported a sensory change in lip or chin region. From this study it is concluded that there seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion

Synthesis and structure of [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl] methylphenyltin bromide : A novel triorganotin halide having a configurationally stable chiral tin center

Reaction of [2-(4, 4-dimethyl-2-oxazoline)-5-methylphenyl]copper with dimethyltin dibromide or methylphenyltin dibromide affords [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]dimethyltin bromide (1) and [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]methylphenyltin bromide (2), respectively. The crystal structure of 2 has been determined by X-ray diffraction methods. C{1}{9}H{2}{2}BrNOSn is monoclinic, space group P2{t}/a with a = 18.1258(9), b = 11.5704(11), c = 9.5315(6) @9, @b = 95.143(6)}o{ and Z = 4, final R = 0.038 for 2760 observed reflections. As a result of intramolecular coordination of the nitrogen atom of the oxazoline ring to the tin atom, the geometry about tin in 1 is trigonal bipyramidal. The carbon ligands are at the equatorial sites, while the more electronegative nitrogen and bromine atoms are at the axial positions. An }1{H NMR spectroscopic study showed that in solution the chiral tin center is configurationally stable up to 120}o{C )the highest temperature studied)

Synthesis and structure of [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl] methylphenyltin bromide : A novel triorganotin halide having a configurationally stable chiral tin center

Reaction of [2-(4, 4-dimethyl-2-oxazoline)-5-methylphenyl]copper with dimethyltin dibromide or methylphenyltin dibromide affords [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]dimethyltin bromide (1) and [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]methylphenyltin bromide (2), respectively. The crystal structure of 2 has been determined by X-ray diffraction methods. C{1}{9}H{2}{2}BrNOSn is monoclinic, space group P2{t}/a with a = 18.1258(9), b = 11.5704(11), c = 9.5315(6) @9, @b = 95.143(6)}o{ and Z = 4, final R = 0.038 for 2760 observed reflections. As a result of intramolecular coordination of the nitrogen atom of the oxazoline ring to the tin atom, the geometry about tin in 1 is trigonal bipyramidal. The carbon ligands are at the equatorial sites, while the more electronegative nitrogen and bromine atoms are at the axial positions. An }1{H NMR spectroscopic study showed that in solution the chiral tin center is configurationally stable up to 120}o{C )the highest temperature studied)