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Biomedical subjects

H F Morris

Publications and source records attributed to H F Morris.

At least 19 recordsLinked to original sources
PubMed2000

The efficacy of a counter-rotational powered toothbrush in the maintenance of endosseous dental implants.

BACKGROUND: Although most patients with implants have lost their natural teeth because of poor oral hygiene, limited data exist to guide practitioners in their recommendations of home-care regimens for their patients' endosseous dental implants and maintenance of peri-implant soft-tissue health. The authors conducted a study to compare the home-care effectiveness of a counter-rotational powered tooth-brush with that of conventional home-care regimens. METHODS: Before starting the six-year study, the authors trained 85 clinical investigators at 32 dental research centers across the United States in gathering periodontal data. Data for 2,966 implants were entered into a centralized database. Outcomes were derived from 24-month observations of a subset of the implants studied. RESULTS: Repeated-measures analysis of the toothbrushing methods used on 2,966 implants showed that the counter-rotational powered toothbrush removed plaque significantly better than manual methods (P < .0001 Wald statistic) from all implant surfaces and at all recall intervals up to 24 months. Similar results were demonstrated for the gingival index. CONCLUSIONS: The counter-rotational powered brush appears to be well-suited for home-care regimens aimed at maintaining optimal peri-implant soft-tissue health in patients with dental implants. CLINICAL IMPLICATIONS: The importance of maintaining the health of the peri-implant tissues is well-recognized by the dental profession. The counter-rotational powered toothbrush is an effective tool in meeting the oral hygiene challenges associated with implant prosthesis maintenance.

Anti-Infective Agents, Local↗
PubMed1999

Money matters.

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Conflict of Interest↗
PubMed1998

Hydroxyapatite-coated implants: a case for their use.

The information on which this article is based comprises a small fraction of the large database compiled from the DICRG study. These results represent the early performance for HA implants (up to 36 months). The study has been ongoing for 6 years, and there are more than 2,000 implants with 4-year data and 1,500 with 5-year data. These data are similar to the 36-month data, and when they are eventually released, they are likely to reinforce the results reported here. Meanwhile, the evidence presented in this article, along with other corroborating studies cited in the introduction, are sufficient grounds to reach the following conclusion: The ideal implant design and material is one that is easy to use, requires average skills, involves minimal bone trauma, presents a biocompatible contact surface, and produces a high rate of survival in most patients. Based on 36-month survival in the DICRG study, HA-coated implants appeared to satisfy these basic requirements better than the other implants used in the study. HA-coated implants were placed in the most challenging bone types and jaw region, in patients with compromised medical histories, by dentists with different training, skills, and experience, under less than ideal clinical conditions, and still showed the highest survival rates of all implants at every point in the treatment up to 36 months.

Antibiotic Prophylaxis↗
PubMed1998

Factors affecting implant mobility at placement and integration of mobile implants at uncovering.

This study examined 1) factors that contributed to implant stability at placement and 2) the likelihood for an implant that was mobile at placement to osseointegrate. Eighty-one (3.1%) of 2,641 implants placed by the Dental Implant Clinical Research Group between 1991 and 1995 were found to be mobile at placement. Seventy-six (93.8%) of the 81 mobile implants were integrated at uncovering compared to 97.5% for the 2,560 immobile implants. Variables that influenced mobility at placement included patient age, implant design and material, anterior-posterior jaw location, bone density, and use of a bone tap. Hydroxyapatite (HA)-coated implants were slightly more likely to be mobile at placement (P = 0.324) than non-hydroxypatite (HA)-coated implants. Of the 54 HA-coated implants that were mobile at placement, all (100%) integrated, while only 17 (81.5%) of the 22 mobile non-HA-coated implants integrated (P = 0.003). Mean electronic mobility testing device values (PTVs) at uncovering for all implants mobile or immobile at placement that integrated were -2.9 and -3.6 respectively. PTVs for HA-coated implants that were mobile (-3.5 PTV) or immobile (-4.0 PTV) at placement differed by 0.5 PTV, whereas non-HA-coated implants exhibited a greater difference of 1.2 PTVs at uncovering. HA-coated implants, regardless of mobility at placement, integrated more frequently and exhibited greater stability than non HA-coated implants.

Adult↗
PubMed1997

Positive effect of surgical experience with implants on second-stage implant survival.

This Dental Implant Clinical Research Group study defined a learning curve for dental implant placement. Implants placed by inexperienced surgeons (< 50 implants) failed twice as often as those placed by experienced surgeons (> or = 50 implants). Implants placed during the first 6, 8, 10, 12, and 16 cases were compared with all others. The greatest difference was seen between the first nine cases and all others (P = .001), with later cases failing significantly less often. Inexperienced surgeons had more failures in the first nine cases (5.9%) than more experienced surgeons (2.4%). Surgeons with little or no previous experience must expect a definite learning curve. Previous experience may transfer and result in a shallower learning curve for subsequent systems.

Clinical Competence↗
PubMed1997

The influence of preoperative antibiotics on success of endosseous implants up to and including stage II surgery: a study of 2,641 implants.

According to the American College of Surgeons, complex oral surgical procedures, including the transoral placement of endosseous implants, are of the type that may require prophylactic antibiotics. However, the routine use of prophylactic antibiotics in the field of dental implantology continues to be controversial, and their utilization varies widely. No data from a randomized prospective clinical study of the prophylactic use of antibiotics in implant surgery have been previously published. As part of the comprehensive Dental Implant Clinical Research Group clinical implant study, the preoperative or postoperative use of antibiotics, the type used, and the duration of coverage was left to the discretion of the surgeon. These data were recorded and correlated with failure of osseointegration during healing (stage I) and at stage II surgery (uncovering). The results showed that significantly fewer failures occurred when preoperative antibiotics were used.

Anti-Bacterial Agents↗
PubMed1997

The influence of 0.12% chlorhexidine digluconate rinses on the incidence of infectious complications and implant success.

The effect of perioperative chlorhexidine on the frequency of infectious complications through stage II was examined. Chlorhexidine was used perioperatively in 54.6% of patients (52.5% of implants) in a Dental Implant Clinical Research Group study with a database of 2,641 implants (595 patients). With chlorhexidine, there was a significant reduction in the number of infectious complications (4.1% vs 8.7%). Two percent of implants failed in the absence of an infectious complication, whereas 12% with infectious complications failed. This sixfold difference is highly significant. Chlorhexidine may reduce microbial complications when used in the immediate perioperative period.

Adult↗
PubMed1997

The influence of type of incision on the success rate of implant integration at stage II uncovering surgery.

In 1991, the Dental Implant Clinical Research Group comprising 30 Department of Veterans Affairs medical centers and two dental schools initiated a long-term clinical study to investigate the clinical performance of implants within the Spectra-System (Core-Vent Corporation, Las Vegas, NV). This article focuses on a portion of the study database related to incision type, implant success rates, and response of crestal bone up to the time of surgical uncovering. The crestal incision was used for 1,705 implants (381 patients) and the remote incision for 593 implants (141 patients). No statistically significant difference (P = .092 chi-square statistic) was found in implant integration or the response of crestal bone.

Adult↗
PubMed1997

Distribution of bone quality in patients receiving endosseous dental implants.

Knowledge of the distribution of bone quality in the various jaw regions assists the clinician in dental implant treatment planning. Bone quality was assessed with radiographs and tactile sensation for 2,839 implants at the time of placement into four anatomic regions of the jaw. The Lekholm-Zarb classification system was used. Overall, bone quality types 1 and 4 were found much less frequently than types 2 and 3. Although variations in density existed in each region, quality 2 bone dominated the mandible, and quality 3 bone was more prevalent in the maxilla. For both anterior and posterior jaw regions, types 2 and 3 bone predominated. The anterior mandible had the densest bone, followed by the posterior mandible, anterior maxilla, and posterior maxilla.

Adult↗
PubMed1997

Bone quality and implant design-related outcomes through stage II surgical uncovering of Spectra-System root form implants.

Failure rates at second-stage surgery were reported for the ongoing Dental Implant Clinical Research Group studies of the Spectra-System (Core-Vent Corporation, Las Vegas, NV) implants. As of May 1995, 69 implants failed out of 2,633 placed and uncovered. The overall failure rate was 2.6%, with 3.6% in bone quality 1 (BQ-1), 2.4% in BQ-2, 2.5% in BQ-3, and 3.1% in BQ-4. HA-coated cylinders had the lowest number of failures and titanium alloy baskets the highest. The basket design failed more often in the posterior jaw areas; 9 of 32 clinical centers (28%) accounted for 72% of these failures.

Adult↗
PubMed1997

The influence of bone quality on Periotest values of endosseous dental implants at stage II surgery.

Periotest values (Periotest, Siemens AG, Bensheim, Germany) were recorded as a baseline variable at surgical uncovering in the ongoing multicenter, prospective clinical studies of the Dental Implant Clinical Research Group, which uses implants from the Spectra-System (Core-Vent Corporation, Las Vegas, NV). For 2,212 osseointegrated implants, the mean Periotest value (PTV) of mandibular implants was -4.14 (anterior, -4.22; posterior, -4.06) versus -3.24 for maxillary implants (anterior, -2.91; posterior, -3.91). Implants in the densest bone (quality 1) had the lowest mean PTV (-4.13), followed by quality 2 (-4.00), quality 3 (-3.58), and quality 4 (-2.64).

Adult↗
PubMed1997

Success of multiple endosseous dental implant designs to second-stage surgery across study sites.

A multicenter clinical study of dental implants is being conducted by the Dental Implant Clinical Research Group to investigate the influence of implant design, application, and site on clinical performance and crestal bone. This article reports on the percentage of success up to implant uncovering for different implant designs and the distribution of failures across study sites. Data from 2,847 implants placed at 32 study sites were analyzed. Percentages of success up to implant uncovering were calculated for study implants overall, by implant design, by implant design within study strata, and according to individual study sites and quartile groupings of sites based on success. Comparisons were made, with chi-square and exact tests employed where appropriate. Differences were found between the different implant designs for the study overall, and between implant designs within the different study strata. Although some implant designs were found to have generally high success across study sites, some study sites designated as having surgeons with less experience tended to have higher failure levels, and one implant design failed at higher rates in a subset of study sites. The percentage and distribution of implant failures varied across study sites and by implant design. These differences appeared to be in part related to the level of experience of the surgeons. Further investigation should focus on identification of factors that contribute to higher success in implant placement with different implant designs.

Adult↗
PubMed1997

Periotest values of dental implants in the first 2 years after second-stage surgery: DICRG interim report no. 8. Dental Implant Clinical Research Group.

In 1991, the Dental Implant Clinical Research Group initiated a long-term clinical study in cooperation with the Department of Veterans Affairs to investigate the influence of implant design, application, and site of placement on clinical performance and crestal bone height. As part of this investigation, Periotest values for 2,212 root from implants were determined at second-stage surgery and during a 24-month follow-up period. Mean Periotest values decreased for implants placed in quality 1 and 2 bone, did not change for implants in quality 3 bone, and increased for implants in quality 4 bone. Implants in the posterior maxilla and single implants in the anterior maxilla had increasing mean Periotest values as compared with decreasing values for implants in other regions. Mean Periotest values for uncoated implants decreased gradually to approach those of hydroxyapatite-coated implants.

Adult↗
PubMed1997

Postmortem histologic evaluation of hydroxyapatite-coated cylinder and titanium alloy basket implants in situ for 37 months in the posterior mandible. Dental Implant Clinical Research Group.

Histologic examination of the tissues surrounding a titanium alloy basket implant and a hydroxyapatite-coated titanium cylinder implant from the mandible of a cadaver were examined. The 67-year-old man died 37 months after first-stage surgery from cardiovascular failure. Clinical and radiographic examinations indicated that the implants were functional, immobile, and integrated. Light microscopy revealed that the gingival tissues adjacent to the implants were healthy and, in general, free of inflammatory cells. The transmucosal area demonstrated a tight connective tissue apposition to the implants. The sulcular epithelial appearance was similar to that of a natural tooth. Histomorphometric analysis revealed that 72.2 percent of the basket implant and 75.3 percent of the hydroxyapatite-coated implant were in direct contact with bone. Generally, the bone along the surface of the basket implant was thicker than the bone along the surface of the hydroxyapatite-coated cylinder. Bone grew through the vent hole areas of both implants.

Aged↗
PubMed1997

The influence of maxillary sinus augmentation on the success of dental implants through second-stage surgery.

An interim evaluation of the status of 102 implants placed in 42 augmented sinuses in 27 patients involved in an alternate category of the Dental Implant Clinical Research Group's long-term, randomized, prospective clinical investigation is presented. Autogeneic, allogeneic, and alloplastic sinus grafts were used, individually or mixed. Through second-stage surgery, 101 implants were found to be integrated. The mean Periotest value at uncovering was -3.36, with a standard deviation of 4.19. The results suggest that root form implants placed in augmented sinuses are successful through second-stage surgery, regardless of the augmentation material or implant design used.

Adult↗
PubMed1994

Assessment of implant mobility at second-stage surgery with the Periotest: DICRG Interim Report No. 3. Dental Implant Clinical Research Group.

Many of the presently used methods of evaluating osseointegration at implant uncovering are highly subjective. The Periotest is claimed to offer a more objective means to assess osseointegration by means of microcomputer-controlled percussion. Investigators involved in a long-term clinical study of dental implants being conducted by the Dental Implant Clinical Research Group used the Periotest to evaluate the mobility associated with all study implants at second-stage surgery and correlate the Periotest values with various bone densities. The Periotest values for 1,838 root form implants ranged from -8 to +25. Implants that appeared to be osseointegrated at uncovering recorded a mean Periotest value of -3.37 +/- 3.25, while nonosseointegrated implants had a mean Periotest value of +13.87 +/- 14.27. Mean Periotest values were -3.82 +/- 3.04 for quality 1 bone, -3.70 +/- 3.06 for quality 2 bone, -3.31 +/- 3.18 for quality 3 bone, and -1.29 +/- 3.57 for quality 4 bone. The Periotest has the potential of being a valuable instrument for assessing the status of osseointegration at second-stage surgery.

Alveolar Process↗