An observational study in Dimensional Alterations, sponsored by University of Bern. Completed at 1 site in Switzerland. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2015-03-31.
Sponsored by University of Bern · Observational
Bone modeling after tooth extraction has a major consequence on implant therapy, in particular in the esthetic zone. In esthetic sites, no tissue loss should occur if an optimal esthetic outcome is expected. Recent experimental studies in dogs have shown that neither an immediate implant insertion nor ridge preservation techniques can prevent this bone modeling process.
Background
The alveolar process is a tooth dependent tissue and develops in conjunction with the eruption of teeth. The size and the form of the tooth, the axis of eruption and eventual inclination determine the local volume as well as the shape of the alveolar process. It has been shown that after removing all teeth in humans, the alveolar ridge undergoes a process of resorption and atrophy.
In a recent animal study, Cardaropoli et al. (2003) assessed the healing events occurring in the extraction socket following tooth removal. The findings of this study demonstrated that the healing of an extraction socket involved a series of events including the formation of a coagulum that was replaced by a provisional connective tissue matrix, woven bone and lamellar bone and bone marrow. On day 30, mineralized bone occupied 88% of the socket volume. Hard tissue formation had started already after 2 weeks of healing, and then, after a month, the socket was filled with woven bone. Later, the woven bone was gradually replaced by lamellar bone and bone marrow. After 3 months of healing, a hard tissue bridge was consistently found to cover the crestal portion of the extraction site, which was formed by woven bone and lamellar bone. Araújo et al. (2005) analysed in an experimental study in dogs the ridge alterations following the extraction of premolars in the mandible. The authors observed that the resorption of the buccal and lingual walls occurred in two overlapping phases. Phase 1: The bundle bone - that lost its function and blood supply - was resorbed and replaced with woven bone. Vertical resorption was considerably greater on the buccal aspect of the alveolar crest, since this bone wall was much thinner then the lingual wall and was primarily comprised of bundle bone. Phase 2: An additional resorption occurred from the outer surfaces of both bone walls. The reason for this additional resorption has not been clearly ascertained. The hypothesis could be: Impaired superficial vascularisation by raising a mucoperiosteal flap; adjusting to the lack of continuous function; or the reestablishment of the ridge shape, which is genetically determined in the absence of teeth. A recent animal study confirmed that flap elevation plays an important role for a more pronounced superficial bone resorption following extraction , therefore, it seems critical that tooth extraction should be carried out without elevation of a mucoperiosteal flap. Even ridge preservation techniques are not able to prevent the contour changes after tooth extraction.
Objective
The aim of the present clinical study is to examine the dimensional changes of the alveolar ridge following single tooth extraction in the anterior maxilla of patients, in particular on the facial aspect of the alveolar ridge. These horizontal and vertical changes will be sequentially documented up to 8 weeks of healing before an implant is inserted using the concept of early implant placement. The study will also provide information about the anatomic situation of the facial bone wall in the anterior maxilla at the time of extraction, and the prevalence and extent of bone deficiencies on the facial aspect, when teeth need to be extracted.
Methods
To document these changes over time, two methods will be applied. Firstly, two cone beam computed tomographies (CBCT) will be obtained, one directly after tooth extraction, the other one at 8 weeks of socket healing prior to implant placement. The two CBCT's will be analyzed with a novel software program (InVivo Dental). Secondly, consecutive impressions will be made at day 0 (day of extraction), day 14, 28, 42, and 56 to digitally produce virtual 3D study models. These models can be analyzed with another software program (Geomagic) to document the variations of the soft tissue in the extraction site.
University of Bern is the lead sponsor of 207 studies on the registry; 47 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The group is selected from the referred patient pool. Age 18 or older. Absence of significant medical conditions. Sites with a need for single tooth extraction in the anterior maxilla.
Exclusion Criteria
One group observation study
Device: Cone beam computed tomography (CBCT)
Dimensional changes are documented over a healing period of 8-weeks following single tooth extraction. To document these changes over time, two methods will be applied. Firstly, two cone beam computed tomographies (CBCT) will be obtained, one directly after tooth extraction, the other one at 8 weeks of socket healing prior to implant placement. The two CBCT's will be analyzed with a novel software program (InVivo Dental). Secondly, consecutive impressions will be made at day 0 (day of extraction), day 14, 28, 42, and 56 to digitally produce virtual 3D study models. These models can be analyzed with another software program (Geomagic Studi 10) to document the variations of the soft tissue in the extraction site.
Change from baseline in bone loss
Measured by segmented surface model superimpositions. Changes in bone loss between baseline and 8 week healing period using CBCT technology. From the Digital Imaging and Communications in Medicine (DICOM) files two surface mesh model were generated, which were superimposed and the changes were subsequently analyzed.
Time frame: 2-, 4-, 6-, 8-weeks
Change from baseline in soft tissue loss
Changes in soft tissue loss at baseline, 2-, 4-, 6- and 8 weeks were analyzed be dental impressions, which were superimposed as well and the changes were analyzed.
Time frame: 2-, 4-, 6-, 8-weeks
Correlation between baseline facial bone thickness and dimensional soft tissue alterations during healing.
To measure correlation, the Spearman Rank Correlation Coefficient was calculated. Nonparametric models for longitudinal data were applied to analyze the impact of bone wall phenotype and healing period upon dimensional alterations.
Time frame: At baseline and 8-weeks
This study is completed, as verified in Mar 2015. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University of Bern