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ePaper created 2016-03-07, 22:38:59 | version 1.38.0
Volume 2 | Issue 1/2016 19 Journal of Oral Science & Rehabilitation I m pla nt po si ti o ni ng wi thi n e xtracti o n so cke ts Clinical eva lua tion (Table 1) After implant placement, residual marginal bone defects were observed that were 4.8 ± 1.3 mm deepand1.2 ± 0.4 mmwideatthelingualaspectof theB-sitesand4.3 ± 1.3 mmdeepand1.2 ± 0.3 mm wide at the buccal aspect of the L-sites. The dis- tance between the lingual bone crest and the im- plantshoulderwas0.4 ± 0.3 mmattheB-sitesand 1.5 ± 0.8 mm at the L-sites, the difference being statistically significant (p = 0.017). This indicates that,despitetheimplantmarginbeingplacedflush with the buccal bone crest at both the B- and L- sites, the implant was approximately 1.1 mm deeperwithrespecttothelingualbonycrestwhen positioned lingually within the extraction socket comparedwithbuccalpositioning. Histologic a l eva lua tion Ground sections showing examples of healing at theB-sitesareillustratedinFigure 4andofhealing attheL-sitesinFigure 5. Hard-tissue d im en s ion s (Table 2; Fig. 6) IS–Catthebuccalaspectwas1.6±1.9 mmatthe B-sites and 0.4±0.7 mm at the L-sites. The difference was statistically significant. At the lingual aspect, IS–C was 0.1±0.7mm and -0.8±0.9mm atthe B- and L-sites, respectively. When the absolute instead ofthe relativevalues were taken into account, the bone crest resorp- tionatthelingualaspectwas0.6±0.5 mmatthe B-sites and 0.7±0.4 mm at the L-sites. None of the differences between the B-sites and L-sites for relative and absolute values at the lingual aspectwerestatisticallysignificant. IS–Batthebuccalaspectwas1.9 ± 1.8 mmatthe B-sitesand1.4 ± 0.7 mmattheL-sites.Atthelin- gualaspect,itwas1.7 ± 1.8 mmand1.0 ± 0.8 mm at the B- and L-sites, respectively. None of the differences were statistically significant. At the B-sites, after healing, marginal bone defects were noted. The dimensions ofthe defects were smaller at the buccal (0.3 mm high and 0.2 mm wide) compared with the lingual (1.6 mm high and 1.2mm wide) aspects. When the implants were placed lingually (L-sites), vertical bone de- fectswerefoundbothatthebuccal(1.1 ± 0.9 mm) andatthelingual(1.6 ± 1.2 mm)aspects.Ithasto be considered, however, that the coronal aspect of the defect was included in the abutment re- gion given that IS was located apical to C by ap- proximately0.8 mm.Thesedefectswerenarrow (≤ 0.5 mm). BIC% was similar at both sites, as well as buccolingually, and ranged between 31.2%and35.2%(Table 3). The width of the buccal bone ridge (OC–S) was larger at the L-sites compared with the B- sites. However, the difference was statistically significantonlyatthe1 mmlevel(Fig. 7). So f t- ti ssu e di me nsi o ns (Table 3; Fig. 6) PM–C and PM–B at the buccal aspect were 3.9 ± 0.4 mmand4.2 ± 0.5 mmattheB-sitesand 4.2 ± 0.4 mmand5.1 ± 1.1 mmattheL-sites.None ofthedifferenceswerestatisticallysignificant.The periimplantmucosawaslocatedmorecoronallyat the L-sites (3.8 ± 0.7 mm) compared with the B-sites(2.3 ± 1.7 mm),thedifferencebeingstatisti- cally significant. The width of the periimplant mucosawas greater at the L-sites comparedwith the B-sites. The differences were statistically sig- nificantatalllevelsconsidered(Fig. 7). Table 2 Histological hard-tissue dimensions (mm; n = 7). Mean values (standard deviations) and medians (25th ; 75th percentiles) are reported. Table 3 Histological soft-tissue dimensions (mm) and BIC% (n = 7). Mean values (standard deviation) and medians (25th ; 75th percentiles) are reported. Fig. 6 Graphic showing the mean values of the dimensions of the periimplant hard and soft tissue. IS: implant shoulder; C: top of the adjacent bony crest; B: most coronal point of contact between the bone and implant; PM: top of the mucosal margin. Fig. 7 Graphic showing the mean values of the alveolar soft- and hard-tissue width at the buccal aspect after four months of healing. The continuous lines represent the width of the tissue at the L-sites, and the dotted lines represent the width at the B-sites. Red and blue lines represent the mucosal and bone widths, respectively. IS: implant shoulder. Fig. 6 Fig. 7 Volume 2 | Issue 1/201619