We thank Katja Kritzler for the commentary on our article. We expressed our concern regarding undeniable potentially looming long-term problems with implant-borne crowns in the esthetic zone in both the introduction and the discussion sections of our article. We have acknowledged that the main advantages of orthodontic space closure are that the hard and soft tissue architectures “remain in a natural state that can better respond to the change over time” and that “it is not possible to exclude a potentially developing infraocclusion, especially in patients with poor interincisor stability.”
However, long-term stability of single-tooth implants in the anterior maxilla was not the subject of our study. The aim was to repeat the study of Armbruster et al from 2005, in which “all 12 cases were photographed after the completion of orthodontic treatment and any restorative dental work,” and not after years in retention, to evaluate whether the introduction of new techniques in implantology and periodontics over the last 10 years has improved the esthetic appeal of implant-borne crowns for congenitally missing maxillary lateral incisors, as suggested by various research groups. Our study clearly shows that the esthetic outcomes in the short term are rated significantly better than 10 years ago—nothing more and nothing less. It was not our intention to interpolate long-term esthetics or functional stability of single-tooth implants in the anterior maxilla from the study, for which sound scientific evidence is currently not available.
We refer to the latest Foundation for Oral Rehabilitation Consensus Conference on the rehabilitation of missing single teeth in October 2015 in Mainz, Germany, during which 11 top experts in the field, selected on objective criteria, such as publications, major contributions to the subject of missing single teeth, and citation indices, presented systematic reviews that were consecutively published in the European Journal of Oral Implantology in summer 2016. A systematic review by Kiliaridis et al, evaluating all relevant articles reporting on treatment options for congenitally missing lateral incisors between 1975 and 2015 evidenced that “definitive conclusions [about the superiority of orthodontic space closure by canine mesial repositioning and reshaping or by a prosthodontic intervention], cannot be drawn, since randomised controlled trials and more prospective and retrospective studies directly comparing the two therapeutic options” are required.
We agree with Dr Kritzler that orthodontic space closure is more advantageous in terms of an earlier overall end of treatment and for avoidance of infraocclusion, especially in young female patients with a vertical skeletal growth pattern, and that implant insertion should be delayed as long as possible. Moreover, if both treatment options for a specific patient are appropriate, orthodontic space closure should be the preferred choice.
Nevertheless, we do not agree that peri-implantitis, soft-tissue discoloration, and loss of the facial bone wall over the implant must be regarded as inevitable sequelae. Sufficient orthodontic space opening, correct 3-dimensional implant placement, additive hard-tissue or soft-tissue grafts in case of thin periodontal biotypes, coupled with a meticulously executed prosthodontic protocol of a well-coordinated interdisciplinary team, can create a stable hard and soft peri-implant framework in most patients.
Because our group is interested in shedding more light on the topic of long-term outcomes of treatment for agenesis of the maxillary lateral incisors with orthodontic space closure vs space opening, we are currently collecting data from our treated patients 5 to 10 years posttreatment, with the goal to publish a study with comparative long-term results, of which only 5 exist in the current literature.