Immediately loaded titanium implant with a tissue-stabilizing/maintaining design ('beyond platform switch') retrieved from man after 4 weeks: A histological and histomorphometrical evaluation. A case report

Dental School, University of Chieti-Pescara, Chieti, Italy, and Private Practice, Bologna, Italy.
Clinical Oral Implants Research (Impact Factor: 3.89). 04/2008; 19(3):276-82. DOI: 10.1111/j.1600-0501.2007.01449.x
Source: PubMed


After implant insertion and loading, crestal bone usually undergoes remodeling and resorption. If the horizontal relationship between the outer edge of the implant and a smaller-diameter component ('platform switching') is altered, there seems to be reduced crestal bone loss. Immediate loading allows immediate restoration of esthetics and function, reduces morbidity, and facilitates functional rehabilitation.
Three Morse cone connection implants were inserted in the right posterior mandible in a 29-year-old partially edentulous patient. The platform of the implant was inserted 2 mm below the level of the alveolar crest. After a 1-month loading period, the most distal mandibular implant was retrieved with a trephine bur for psychological reasons.
At low-power magnification, it was possible to see that bone was present 2 mm above the level of the implant shoulder. No resorption of the coronal bone was present. No infrabony pockets were present. At the level of the shoulder of the implant, it was possible to observe the presence of dense connective tissue with only a few scattered inflammatory cells. Newly formed bone was found in direct contact with the implant surface. The bone-implant contact percentage was 65.3+/-4.8%.
Abutments smaller than the diameter of the implant body (platform switching) in combination with an absence of micromovement and microgap may protect the peri-implant soft and mineralized tissues, explaining the observed absence of bone resorption. Immediate loading did not interfere with bone formation and did not have adverse effects on osseointegration.

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    • "This anatomical characteristic must be taken into consideration if pronounced buccal bone resorption is to be avoided following immediate implant placement (Covani et al. 2004; Ara ujo et al. 2005b, 2006a,b; Barone et al. 2011). Other possible causes of soft and hard tissue remodeling around have been formulated, which include surgical trauma (Esposito et al. 1998), implant abutment microgaps (Broggini et al. 2006), biologic width establishment (Berglundh & Lindhe 1996), apicocoronal implant position (Negri et al. 2012a,b; Calvo-Guirado et al. 2013a, 2014b), buccolingual position (Buser et al. 2004; Chen et al. 2007; Kan et al. 2009), implant abutment design (Degidi et al. 2008; Buser et al. 2011; Calvo- Guirado et al. 2011a, 2014c; Rodr ıguez et al. 2011), soft tissue grafting (Grunder 2011; Tsuda et al. 2011), alveolus defect shape (Kan et al. 2007) and defects around the immediate implant (Botticelli et al. 2004a; Kan et al. 2009; Ferrus et al. 2010). "
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    ABSTRACT: The aim of this study was to evaluate the effects of topical applications of melatonin over implant surfaces placed immediately after extraction by means of histological and histomorphometric analysis of peri-implant tissues. Six American foxhound dogs were used in the study; mandibular premolar distal roots were extracted. Thirty-six immediate conical implants were randomly assigned to the distal site on each site of the mandible in three groups: (Group CI) 12 titanium implants alone; (Group MI) 12 titanium implants supplemented with melatonin; and (Group DI) 12 titanium implants supplemented with vitamin D (DI). Prior to implanting test, implants (MI) were submerged in melatonin 5% solution, and implants from (DI) group were submerged in vitamin D 10% solution. No treatment was applied at control implants. After 12 weeks, animals were sacrificed. Block sections were obtained and processed for mineralized ground sectioning. Bone-to-implant contact (total BIC), new bone formation (NBF), inter-thread bone (ITB) and histological linear measurements (HLM) were analyzed. At 12 weeks, all implants were clinically stable and histologically osseointegrated. Total BIC values were 48.36 ± 7.45* for the MI group and 44.82 ± 10.98 for the CI group (P = 0.035) with statistically significant difference between groups. BIC% were 41.36 ± 3.93 for MI and 41.34 ± 9.26 for CI (P > 0.05). Inter-thread bone formation values were MI 15.99 ± 2.43* and CI 14.79 ± 3.62 (P = 0.03), MI showing significantly better results. No statistically significant differences in peri-implant new bone formation could be found between the two groups: MI 25.37 ± 2.32, CI 26.55 ± 7.75 (P > 0.05). Linear measurements showed that the MI group showed significantly less lingual crestal bone loss (CBL) (MI 0.52 ± 0.74*, CI 0.92 ± 1.98) (P = 0.045) and less lingual peri-implant mucosa (PIM) (MI 3.13 ± 1.41*, CI 3.71 ± 1.81) (P = 0.042). No significant differences were observed in the buccal aspect. Within the limitations of this animal study, the topical application of melatonin improved bone formation around immediate implants and reduced lingual bone and lingual peri-implant mucosa, after 12 weeks of osseointegration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
    Full-text · Article · Apr 2015 · Clinical Oral Implants Research
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    • "Furthermore, the reduced size of bone loss seems to be inversely correlated to the extent of the horizontal platform mismatch (Canullo et al. 2010a and Cocchetto et al. 2010) and to be independent of the bacterial composition of the biofilm since the peri-implant microbiota at implants with and without PS was almost indistinguishable (Canullo et al. 2010b). In accordance with the beneficial concept of PS, histological human data displayed minimal bone loss and a reduced dimension of the inflammatory cell infiltrate indicated by its limited apical extension beyond the platform in these implants (Degidi et al. 2008, Luongo et al. 2008). Although histological characterization of peri-implant soft tissue biopsies taken from implants 4 years after restoration either with PS or platform matching (PM) abutments was not different in terms of the extent of inflamed connective tissue, the microvascular density and the collagen content, the authors speculated that early soft tissue events such as the formation of the biological width may be different and responsible for the diminished bone loss around PS implants (Canullo et al. 2011). "
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    ABSTRACT: The purpose of this ongoing randomized study was to assess differences in bone level changes and success rates using implants supporting single crowns in the posterior mandible either with platform matched or platform switched abutments. Patients aged 18 and above, missing at least two teeth in the posterior mandible and with a natural tooth mesial to the most proximal implant site were enrolled. Randomization followed implant placement. Definitive restorations were placed after a minimum transgingival healing period of 8 weeks. Changes in crestal bone level from surgery and loading (baseline) to 12-month post-loading were radiographically measured. Implant survival and success were determined. Sixty-eight patients received 74 implants in the platform switching group and 72 in the other one. The difference of mean marginal bone level change from surgery to 12 months was significant between groups (p < 0.004). Radiographical mean bone gain or no bone loss from loading was noted for 67.1% of the platform switching and 49.2% of the platform matching implants. Implant success rates were 97.3% and 100%, respectively. Within the same implant system the platform switching concept showed a positive effect on marginal bone levels when compared with restorations with platform matching.
    Full-text · Article · May 2014 · Journal Of Clinical Periodontology
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    • "may affect peri-implant resorption (Schou et al. 2006), because the bacterial contamination of the implant–abutment junction from the oral cavity was shown to trigger hard tissue response (Cochran et al. 1997). Many strategies have been advocated to clinically minimize the effect of this contamination: mechanical improvement of the implant/abutment connection stability (Van Assche et al. 2011), implant/abutment microgap shifting from the vital bone (Degidi et al. 2008; Vigolo & Givani 2009; Canullo et al. 2010a), diminishing times of the abutment dis/reconnection (Canullo et al. 2010b); nevertheless, a minimal bone resorption (0.5 mm) has been observed in longitudinal analysis (Annibali et al. 2012). "
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    ABSTRACT: A lack of evidence is present in literature regarding the clinical relevance of micropollution and bacterial contamination present on customized titanium abutments following laboratory stages and steaming cleaning procedures. To preserve abutments from such pollutants, plasma of argon cleaning of customized abutments was advocated. The aim of this prospective, randomized, match-paired, triple-blinded, controlled, clinical trial is to longitudinally assess radiographical marginal bone-level changes around implants restored according to the platform switching and "one-abutment-one-time" concepts, using commercially available abutments, with and without plasma of argon cleaning treatment after customization. Thirty patients with thin gingival biotype, a history of periodontal disease, and in general good health received one implant in the anterior maxilla or premolar region. Patients were randomly assigned to control (abutment subjected only to usually adopted cleaning protocol by steam) and test group (abutment subjected to plasma of argon treatment). Periapical standardized digital radiographs were taken at the time of crown connection (T0 ), 6 (T1 ) and 24 months after the final restoration (T2 ). Average mesial-distal bone-level changes mean values with standard deviations (SD) were calculated. The Mann-Whitney U-test was selected to identify differences in bone-level changes between test and control groups. An average interproximal bone loss of 0.16 mm (SD: 0.17) and 0.07 mm (SD: 0.34) was revealed in the control and test group at 6 months (T1 ), respectively, while after 24 months, groups showed a mean bone-level changes of 0.38 mm (SD: 0.44) and 0.11 mm (SD: 0.14), respectively. Statistically significant differences among control and test groups were found at both time points. Intergroup comparison relived absence of statistically significant difference. Plasma-cleaning treatment of implant titanium abutments, together with platform switching and one-abutment-one-time concepts, could be favorable in terms of hard-tissue-level changes, also in critical conditions such as in patients with a history of periodontal disease, presenting thin gingival biotype.
    Full-text · Article · Nov 2013 · Clinical Oral Implants Research
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