Implants placed in fresh extraction sockets in the maxilla: clinical and radiographic outcomes from a 3-year follow-up examination.

AIM: The aim of this prospective, randomized, controlled multicenter study was to determine the 3-year efficacy and stability of the soft and hard tissues at implants with a different geometry that were placed in fresh extraction sockets. MATERIAL AND METHODS: Implants with two different configurations, cylindrical (Group A) or conical/cylindrical (Group B) were installed, and healing abutments were attached. Sixteen weeks after implant placement, subjects returned for a re-entry procedure. Prosthetic restorations were delivered 22 weeks after implant placement. Each subject was placed in a 3-year follow-up program, including examinations at yearly visits including various soft tissue and bone level parameters. RESULTS: The percentage of sites that were considered inflamed during the follow-up period was stable and varied between 8.8% and 10.2%. The radiographic examinations documented improved bone levels at the final examination and the mean improvement from baseline (placement of permanent restoration; PR) amounted to 0.17 ± 0.67 mm. More than 70% (54 of 76) of the implants monitored in this study suffered no bone loss during the maintenance period. Moreover, there was an obvious "gain" of interproximal soft tissue volume and at the 3-year examination around 25% of all embrasure gaps were completely filled with "papillae". CONCLUSIONS: Both conical/cylindrical and cylindrical implants placed in fresh extraction sockets allowed proper soft and hard tissue healing to occur. At both types of implants, mucosal inflammation was infrequent, marginal bone levels were maintained, and soft tissue volume increased gradually after the placement of the permanent restoration.

Analysis of the socket bone wall dimensions in the upper maxilla in relation to immediate implant placement.

BACKGROUND: Animal and human researches have shown that immediate implant placement into extraction sockets failed to prevent socket dimensional changes following tooth extraction. It has been suggested that a minimal width of 1-2 mm of buccal bone is necessary to maintain a stable vertical dimension of the alveolar crest. AIM: To determine the dimensions of the bony wall at extraction sites in the esthetic zone (anterior teeth and premolars in the maxilla) and relate it to immediate implant placement. METHODS: As part of an ongoing prospective randomized-controlled multicenter clinical study on immediate implant placement, the width of the buccal and palatal bony walls was recorded at 93 extraction sites. RESULTS: The mean width of the buccal and palatal bony walls was 1 and 1.2 mm, respectively (P<0.05). For the anterior sites (canine to canine), the mean width of the buccal bony wall was 0.8 mm. For the posterior (premolar) sites, it was 1.1 mm (P<0.05). In the anterior sites, 87% of the buccal bony walls had a width < or = 1 mm and 3% of the walls were 2 mm wide. In the posterior sites, the corresponding values were 59% and 9%, respectively. CONCLUSIONS: If the criterion of a minimal buccal bone width of 2 mm to maintain a stable buccal bony wall is valid, only a limited number of sites in the anterior maxilla display such a clinical situation. The data suggested that in the majority of extraction sites in the anterior maxilla, thin (< or = 1 mm) buccal walls were present. This, in turn, means that in most clinical situations encountered, augmentation procedures are needed to achieve adequate bony contours around the implant.

Bone dimensional variations at implants placed in fresh extraction sockets: a multilevel multivariate analysis.

AIM: To use multilevel, multivariate models to analyze factors that may affect bone alterations during healing after an implant immediately placed into an extraction socket. MATERIAL AND METHODS: Data included in the current analysis were obtained from a clinical trial in which a series of measurements were performed to characterize the extraction site immediately after implant installation and at re-entry 4 months later. A regression multilevel, multivariate model was built to analyze factors affecting the following variables: (i) the distance between the implant surface and the outer bony crest (S-OC), (ii) the horizontal residual gap (S-IC), (iii) the vertical residual gap (R-D) and (iv) the vertical position of the bone crest opposite the implant (R-C). RESULTS: It was demonstrated that (i) the S-OC change was significantly affected by the thickness of the bone crest; (ii) the size of the residual gap was dependent of the size of the initial gap and the thickness of the bone crest; and (iii) the reduction of the buccal vertical gap was dependent on the age of the subject. Moreover, the position of the implant opposite the alveolar crest of the buccal ridge and its bucco-lingual implant position influenced the amount of buccal crest resorption. CONCLUSIONS: Clinicians must consider the thickness of the buccal bony wall in the extraction site and the vertical as well as the horizontal positioning of the implant in the socket, because these factors will influence hard tissue changes during healing.

Factors influencing ridge alterations following immediate implant placement into extraction sockets.

AIM: To identify factors that may influence ridge alterations occurring at the buccal aspect of the extraction site following immediate implant placement. MATERIAL AND METHODS: In 93 subjects, single-tooth implants were placed immediately into extraction sockets in the maxilla (tooth locations 15-25). A series of measurements describing the extraction site were made immediately after implant installation and at re-entry, 16 weeks later. The implant sites were stratified according to four factors: (i) implant location (anterior/posterior), (ii) cause of tooth extraction (periodontitis/non-periodontitis), (iii) thickness of the buccal bone walls (< or = 1 or > 1 mm) and (iv) the dimension of the horizontal buccal gap (< or = 1 or > 1 mm). RESULTS: (i) The location where the implant was placed (anterior/posterior) as well as (ii) the thickness of the buccal bone crest and (iii) the size of the horizontal buccal gap significantly influenced the amount of hard tissue alteration that occurred during a 4-month period of healing. At implant sites in the premolar segment, the fill of the horizontal gap was more pronounced than in the incisor-canine segment, while the vertical crest reduction was significantly smaller. Furthermore, at sites where the buccal bone wall was thick (>1 mm) and where the horizontal gap was large (>1 mm), the degree of gap fill was substantial. CONCLUSIONS: The thickness of the buccal bone wall as well as the dimension of the horizontal gap influenced the hard tissue alterations that occur following immediate implant placement into extraction sockets.

A prospective, randomized-controlled clinical trial to evaluate bone preservation using implants with different geometry placed into extraction sockets in the maxilla.

AIM: The primary objective of this study was to determine the association between the size of the void established by using two different implant configurations and the amount of buccal/palatal bone loss that occurred during 16 weeks of healing following their installation into extraction sockets. MATERIAL AND METHODS: The clinical trial was designed as a prospective, randomized-controlled parallel-group multicenter study. Adults in need of one or more implants replacing teeth to be removed in the maxilla within the region 15-25 were recruited. Following tooth extraction, the site was randomly allocated to receive either a cylindrical (group A) or a tapered implant (group B). After implant installation, a series of measurements were made to determine the dimension of the ridge and the void between the implant and the extraction socket. These measurements were repeated at the re-entry procedure after 16 weeks. RESULTS: The study demonstrated that the removal of single teeth and the immediate placement of an implant resulted in marked alterations of the dimension of the buccal ridge (43% and 30%) and the horizontal (80-63%) as well as the vertical (69-65%) gap between the implant and the bone walls. Although the dimensional changes were not significantly different between the two-implant configurations, both the horizontal and the vertical gap changes were greater in group A than in group B. CONCLUSIONS: Implant placement into extraction sockets will result in significant bone reduction of the alveolar ridge.

Efficacy of a 0.15% benzydamine hydrochloride and 0.05% cetylpyridinium chloride mouth rinse on 4-day de novo plaque formation.

OBJECTIVE: To evaluate the effect of a mouth-rinse formulation combining benzydamine hydrochloride and cetylpyridinium chloride (BNZ+CPC) in preventing de novo plaque formation, in comparison with CPC and placebo mouth rinses. PATIENTS AND METHODS: This was a controlled, observer-blind, cross-over study. In this model of plaque re-growth, subjects received a session of oral prophylaxis and were directed to withdraw oral hygiene measures for the next 4 days, using only the mouth rinse assigned. The outcome parameters were the plaque index (PlI) and gingival index (GI). In addition, microbiological evaluation of the subgingival microflora, by means of culture, was performed, as well as patient-based variables. Data analysis was carried out using anova for Latin-square design. RESULTS: The analysis of variance showed a significant statistical difference between the BNZ+CPC association and placebo (p<0.0001). No differences between CPC and placebo were detected considering multiple comparisons between treatments. The 90% confidence interval of the differences between BNZ+CPC and CPC showed no equivalence between treatments, being the PlI lower in the BNZ+CPC group. No significant difference between groups in GI was observed. Mean anaerobic colony-forming units (CFU) demonstrated a significant increase between visits in all groups (p<0.001) and differences among groups were not significant. Subjects treated with BNZ+CPC frequently reported "tingling mouth" and "numbness mouth". CONCLUSION: Within the limitations of the study model, the BNZ+CPC combination showed a statistically significant plaque-inhibitory capacity, as compared with the placebo mouth rinse, and an additive effect as compared with CPC. No relevant clinical or microbiological adverse effects were detected.