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AIM: To qualitatively and quantitatively evaluate the formation and maturation of peri-implant soft tissues around 'immediate' and 'delayed' implants. MATERIALS AND METHODS: Miniaturized titanium implants were placed in either maxillary first molar (mxM1) fresh extraction sockets or healed mxM1 sites in mice. Peri-implant soft tissues were evaluated at multiple timepoints to assess the molecular mechanisms of attachment and the efficacy of the soft tissue as a barrier. A healthy junctional epithelium (JE) served as positive control. RESULTS: No differences were observed in the rate of soft-tissue integration of immediate versus delayed implants; however, overall, mucosal integration took at least twice as long as osseointegration in this model. Qualitative assessment of Vimentin expression over the time course of soft-tissue integration indicated an initially disorganized peri-implant connective tissue envelope that gradually matured with time. Quantitative analyses showed significantly less total collagen in peri-implant connective tissues compared to connective tissue around teeth around implants. Quantitative analyses also showed a gradual increase in expression of hemidesmosomal attachment proteins in the peri-implant epithelium (PIE), which was accompanied by a significant inflammatory marker reduction. CONCLUSIONS: Within the timeframe examined, quantitative analyses showed that connective tissue maturation never reached that observed around teeth. Hemidesmosomal attachment protein expression levels were also significantly reduced compared to those in an intact JE, although quantitative analyses indicated that macrophage density in the peri-implant environment was reduced over time, suggesting an improvement in PIE barrier functions. Perhaps most unexpectedly, maturation of the peri-implant soft tissues was a significantly slower process than osseointegration.
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STATEMENT OF PROBLEM: Achieving and maintaining optimal tissue health and esthetics when immediately placing maxillary anterior implants with interim restorations has been challenging and the clinical outcomes heterogenous. PURPOSE: The purpose of this retrospective study was to evaluate the clinical outcomes of immediate placement of maxillary anterior implants with interim restorations and compare the tomographic and clinical results before and after implant placement in participants followed for 1 to 14 years. MATERIAL AND METHODS: Twenty participants receiving 25 postextraction single implants in the anterior maxilla were studied. Clinical parameters included pink esthetic score (PES) and white esthetic score (WES), peri-implant phenotype, implant probing, plaque index, and cone beam computed tomography (CBCT) to compare initial and at least 1 year after crown placement (postoperative). For qualitative variables, a descriptive analysis was carried out. The PES and WES results were analyzed by using nonparametric statistics, the median (ME) and the interquartile range (IQR) were used as summary measures, and the Wilcoxon sum of signs test was used to compare the total scores between the intervention area and the contralateral tooth. To compare pre- and postoperative data points, the paired t test was used (α=.05). RESULTS: Mean ±standard deviation (SD) time of follow-up was 7.6 ±4.2 years. Twenty participants with a mean ±SD age of 62.4 ±11.0 years old received 25 implants. Mean ±SD initial torque value at implant placement was 38.6 ±9.63 Ncm. Bone height at the top of the alveolar ridge (BH) and bone width at the middle of the alveolar ridge (BW2) showed a statistically significant decrease between the initial and subsequent CBCT measurements (both P<.001). Likewise, the bone width at the alveolar crest (BW1) showed a statistically significant decrease between the initial and post-CBCT measurements (P=.006). Facial bone integrity (FBI) revealed a statistically significant increase between the initial and postoperative time periods (P<.001). The PES index showed a median of 9.0 IQR (8-10), statistically lower than the contralateral tooth (P=.032). No significant differences were found for the WES index or for FBI, regardless of the peri-implant phenotype. CONCLUSIONS: Immediate implant placement in the maxillary anterior sextant was found to be a predictable procedure with good esthetic results when the protocol described was used. Labial bone loss is inevitable after tooth extraction but can be compensated for by filling the space with a xenograft material. Long-term gingival tissue integrity was maintained, regardless of phenotype, in periodontally healthy participants.
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PURPOSE OF REVIEW: There is a growing appreciation within the scientific community that cells exhibit regional variation. Whether the variation is attributable to differences in embryonic origin or anatomical location and mechanical loading has not been elucidated; what is clear, however, is that adult cells carry positional information that ultimately affects their functions. The purpose of this review is to highlight the functions of osteocytes in the craniomaxillofacial (CMF) skeleton as opposed to elsewhere in the body, and in doing so gain mechanistic insights into genetic conditions and chemically-induced diseases that particularly affect this region of our anatomy. RECENT FINDINGS: In the CMF skeleton, elevated Wnt/ß-catenin signaling affects not only bone mass and volume, but also mineralization of the canalicular network and osteocyte lacunae. Aberrant elevation in the Wnt/ß-catenin pathway can also produce micropetrosis and osteonecrosis of CMF bone, presumably due to a disruption in the signaling network that connects osteocytes to one another, and to osteoblasts on the bone surface.
