Techniques for grafting the extraction site in preparation for dental implant placement

Evaluation of bone availability for grafts in different donor sites, through computed tomography

Objective

To quantify the bone volume that can be safely withdrawn from 3 donor sites: (1) the mandibular symphysis, (2) the oblique mandibular line and (3) the skullcap.

Methodology

For the symphysis, 200 tomographic exams were evaluated by the extension of the anterior loop of mental foramen, by the nerve, by the distance of the foramens, by the distance between the vestibular cortical and the lingual plates and by the distance between the apexes, or lower anterior teeth, and the mandibular base, using the “distance” tool of the I-CAT Vision, in the panoramic and parasagittal reformations. For the oblique line, 70 TCFC exams were analyzed retrospectively in panoramic and parasagittal reformations, evaluating the thickness of the vestibular cortical and the distance between the cortical and the mandibular canal. For the cranial bone, a hexagonal donor site located in parietal area was considered.

Results

The average dimensions of the bone blocks that can be safely removed from the region of the mandibular symphysis are: 32.27 mm in length, 4.87 mm in height and 4 mm in thickness, providing a volume of 628.61 mm³ available for grafting. In the oblique line, the available bone volume for grafting was 859.61 mm³. In the region of the cranial vault, multiplying the average bone thickness by the area of the hexagon, an average volume of 2,499 mm³ was obtained.

Conclusions

Comparing the donor sites, the bone availability in the cranial vault is 3 times greater than in the mandibular posterior region, and at least 2 times greater than in the mandibular symphysis.

Complex Dental Implant Cases: Algorithms, Subjectivity, and Patient Cases Along the Complexity Continuum

Algorithms for predictable outcomes, or checklists in health care, have been widely supported due to their highly effective outcomes. This article shares "algorithmic roadmaps" to restore single-tooth, partially edentulous, and fully edentulous complex dental implant cases in the patient population. A review of the current literature is presented to provide systematic assessments followed by criteria in a checklist format that allows the surgeon and restorative dentist to determine whether a removable or fixed implant prosthesis is the best patient option. Several cases have been chosen to illustrate the algorithms the authors used to provide an optimized prognosis for surgical/restorative success.

Simple bone augmentation for alveolar ridge defects

Dental implant procedures, both surgical placement and preimplant bone augmentation, have become an integral aspect of the oral and maxillofacial surgeon's practice. The number of dental implants placed each year continues to increase as a result of increasing patient exposure and awareness of dental implants, the increased functional and esthetic dental demands of general practitioners and patients, the overall increase in age of the US patient population, and expanded insurance coverage of dental implant-related procedures. This article outlines relevant surgical procedures aimed toward reconstructing alveolar ridge defects to restore intra-arch alveolar discrepancies before restoration-driven dental implant placement.

Quality assessment of systematic reviews on alveolar ridge preservation

BACKGROUND

The authors conducted a study to assess the quality of systematic reviews (SRs) published on the topic of alveolar ridge preservation (ARP).

TYPES OF STUDIES REVIEWED

The authors conducted a search for SRs on ARP on the basis of a set of eligibility criteria (only SRs involving ARP, with or without meta-analyses, written in English). The authors assessed the quality of the SRs independently of one another by using two established checklists.

RESULTS

The authors selected eight SRs. The results of all of the SRs indicated that ARP was effective in preserving the ridge volume as compared with extraction alone, but it did not fully prevent bone-resorptive events. None of the SRs, however, received the highest possible score in either of the checklists. One SR that had a score of 5 (of a possible 11) using one checklist and 5 (of a possible 14) using the other checklist had the lowest overall score. The results of this assessment revealed that a significant proportion of the investigators in the SRs did not include non-English language articles, perform hand searching of published literature or evaluate the gray literature. Assessment of publication bias and reporting of conflicts of interest also was lacking in some studies. Practical Implications. Although ARP appears to be an effective approach to preventing resorption after tooth extraction, significant structural and methodological variability exists among SRs on this topic. Future SRs on ARP should consider the use of quality assessment checklists to minimize methodological shortcomings for better dissemination of scientific evidence.

Surgical protocols for ridge preservation after tooth extraction. A systematic review

OBJECTIVE

This systematic review aims to evaluate the scientific evidence on the efficacy in the surgical protocols designed for preserving the alveolar ridge after tooth extraction and to evaluate how these techniques affect the placement of dental implants and the final implant supported restoration.

MATERIAL AND METHODS

A thorough search in MEDLINE-PubMed, Embase and the Cochrane Central Register of controlled trials (CENTRAL) was conducted up to February 2011. Randomized clinical trials and prospective cohort studies with a follow-up of at least 3 months reporting changes on both the hard and soft tissues (height and/or width) of the alveolar process (mm or %) after tooth extraction were considered for inclusion.

RESULTS

The screening of titles and abstracts resulted in 14 publications meeting the eligibility criteria. Data from nine of these 14 studies could be grouped in the meta-analyses. Results from the meta-analyses showed a statistically significant greater ridge reduction in bone height for control groups as compared to test groups (weighted mean differences, WMD = -1.47 mm; 95% CI [-1.982, -0.953]; P < 0.001; heterogeneity: I(2) = 13.1%; χ(2) P-value = 0.314) and a significant greater reduction in bone width for control groups compared to the test groups (WMD = -1.830 mm; 95% CI [-2.947, -0.732]; P = 0.001; heterogeneity: I(2) = 0%; χ(2) P-value = 0.837). Subgroup analysis was based on the surgical protocol used for the socket preservation (flapless/flapped, barrier membrane/no membrane, primary intention healing/no primary healing) and on the measurement method utilized to evaluate morphological changes. Meta-regression analyses demonstrated a statistically significant difference favoring the flapped subgroup in terms of bone width (meta-regression; slope = 2.26; 95% IC [1.01; 3.51]; P = 0.003).

CONCLUSIONS

The potential benefit of socket preservation therapies was demonstrated resulting in significantly less vertical and horizontal contraction of the alveolar bone crest. The scientific evidence does not provide clear guidelines in regards to the type of biomaterial, or surgical procedure, although a significant positive effect of the flapped surgery was observed. There are no data available to draw conclusions on the consequences of such benefits on the long-term outcomes of implant therapy.