The present analysis, using a simple and reproducible method for GT assessment, confirmed the existence of gingival biotypes. A clear thin gingiva was found in about one-third of the sample in mainly female subjects with slender teeth, a narrow zone of keratinized tissue and a highly scalloped gingival margin corresponding to the features of the previously introduced "thin-scalloped biotype" (cluster A1). A clear thick gingiva was found in about two-thirds of the sample in mainly male subjects. About half of them showed quadratic teeth, a broad zone of keratinized tissue and a flat gingival margin corresponding to the features of the previously introduced "thick-flat biotype" (cluster B). The other half could not be classified as such. These subjects showed a clear thick gingiva with slender teeth, a narrow zone of keratinized tissue and a high gingival scallop (cluster A2).

If the primary implant stability permits it, immediate single-tooth implants should be instantly provisionalized in the interest of optimal midfacial esthetics.

The authors declare that they have no conflict of interests. The study was supported by the dental department of the Free University of Brussels (VUB). The authors wish to express their gratitude to Nobel Biocare Belgium for their support in providing dental implants. ABSTRACT Purpose:The objective of this prospective study was to assess the overall outcome of immediate single implant treatment in the anterior maxilla after a 3-year observation period. Material and methods: Conclusions:The proposed strategy seems a valuable and predictable treatment option for well-selected patients in the mid-long term as shown by almost full papillary re-growth and a low risk for advanced midfacial recession.

The preliminary results suggest that the proposed strategy can be considered to be a valuable treatment option in well-selected patients.

The rehardening of surface-softened and surface-etched enamel was investigated in vitro and by intraoral exposure. Surface-softened enamel was obtained by treatment with 0.1 M acetic acid buffer solution (pH = 5.5) for 3 h. Surface-etched enamel was obtained by the acid etch procedure used in clinical situations (37% phosphoric acid gel, 30 s). The enamel lesions were treated in vitro, with calcifying solutions for 8 h or were carried for 48 h in an intraoral appliance. Changes at the enamel surfaces were investigated by surface micro-hardness measurements. Following the treatment with calcifying solutions a significantly greater indentation length was observed in surface-etched than in surface-softened enamel. No significant difference in indentation length between both types of enamel lesions was observed following intraoral exposure. It was concluded that the initial rate of rehardening between both types of enamel lesions is comparable. At his stage remineralization occurs in microspaces created in the slightly destroyed enamel structures. The influence of the etch pits on the indentation length becomes dominating when remineralization continues. An obliteration of etch pits was observed in enamel samples treated with the calcifying solution with the highest degree of saturation. It was suggested that freshly prepared highly supersaturated calcifying solutions can be used to enhance mineral appositions in accidental etch pits.