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Biomedical subjects

W Mörmann

Publications and source records attributed to W Mörmann.

At least 19 recordsLinked to original sources
PubMed1992

Computer-designed inlays after 5 years in situ: clinical performance and scanning electron microscopic evaluation.

Eight mesio-occlusodistal adhesive inlays, fabricated from ceramic blocks using a computer-aided design/machining method, were reexamined after 5 years of clinical service. The inlays wre evaluated according to modified US Public Health Service criteria. The results indicated excellent clinical performance, with eight Alfa ratings for wear, recurrent caries, and color match, and five Alfa and three Bravo for marginal discoloration and marginal integrity. Under scanning electron microscope, 81.0% of the tooth-cement interfaces and 84.1% of the cement-inlay interfaces were rated continuous at the occlusal margin. Axially, 73.6% of the tooth-cement interfaces and 87.0% of the cement-inlay interfaces were rated continuous. Although this long-term investigation revealed good clinical performance of the inlays, improvements in the ceramic structure and its properties, the cavosurface design, and the luting composite resin were recently introduced to further optimize quality.

Ceramics↗
PubMed1979

Gingival blood circulation after experimental wounds in man.

Capillary blood circulation following experimental wounding was observed by fluorescein angiography. Contralateral punch wounds 1.5 mm in diameter were made in healthy mandibular labial attached gingiva of 31 volunteers. Areas of ischemia were clearly visible angiographically 6 hours after wounding and were significantly greater in area (P less than 0.05) and wider (P less than 0.01) for wounds in the long axis of mandibular incisors (N = 14) than those on the vertical midline of the gingival papillae (N = 17). The ischemic changes occurred exclusively cranial to the experimental wounds. By the third day the epithelium adjacent to the wound margin in the central part of the ischemic area had necrotized, thus extending the wound coronally. By the seventh day the axial wounds were significantly (P less than 0.001) larger than the papillary wounds. The data strongly suggest that the blood supply of mandibular labial attached gingiva is preferentially oriented in an apico-coronal direction and that the capacity for collateral circulation is dependent upon local differences in vascular structure. The findings are applicable to flap design in periodontal surgery.

Adult↗
PubMed1979

Mucogingival surgery. The subperiosteal vestibule extension. Clinical results 2 years after surgery.

A surgical technique to establish wide zones of attached mucosa was performed in 28 patients presenting with inadequate amounts of attached gingiva. The clinical results of the procedure were monitored over a period of 2 years. Biometric assessment of 112 mucogingival units immediately before and at 1, 3, 6, and 24 months after surgery revealed that the mean width of attached gingiva changed from 1.1 mm to 5.3 mm of attached tissue (gingiva plus vestibular mucosa). A surgically produced increase of 4.9 mm in width (P less than 0.001) and subsequent shrinkage of 0.7 mm or 14% (P less than 0.001) resulted in a total average gain of 4.2 mm of attached mucosa 2 years after surgery (P less than 0.001). A begin/end analysis of the coronal level of clinical periodontal attachment and the extent of gingival recession showed no clinically significant changes. The mean width of keratinized gingiva increased 0.8 mm during the 2-year postoperative period. The subperiosteal vestibule extension is recommended as an alternative to the free autogenous mucosa graft for establishing wide bands of attached mucosa in areas where loss of attached gingiva is associated with mechanical or microbial irritation of the marginal periodontium.

Adolescent↗
PubMed1979

Damaging effects of toothbrush bristle end form on gingiva.

The ability of two different toothbrush bristle ends to produce traumatic gingival abrasion was assessed in a double blind study of 15 male and 15 female young adults. Brushing was performed in a circular fashion using a modified Bass Technique. An apparatus allowing continuous visual feedback of the average brushing force permitted a degree of standardization of the system. The upper left canine and bicuspid area had to be brushed for 30 seconds with cut toothbrush bristles (CP) and with round ended toothbrush bristles (RP) respectively. A two week interval separated the two brushing sessions. Traumatic lesions of the attached gingiva were stained with a disclosing solution, photographed and evaluated planimetrically. The "cut bristles" caused gingival abrasions 30% greater in extent than the round end bristles. The difference was not due to single brushing strokes accidentally greater for the "cut bristles". The size of the lesions was not sex dependent. To prevent gingival damage it is desirable to either round the bristles in production or to rid the bristle ends at least of sharp edges.

Adolescent↗
PubMed1979

[The effect of vascular injuries on the healing of experimental gingival wounds].

Following experimental infliction of stab wounds, the blood circulation in mandibular gingiva attached to the labium was studied in 31 subjects with fluorescence angiography. Ischemic circulatory disturbances six hours after infliction of the wound and enlargement of the wound three days post operationem were all directed cranially. Blood flow in this area of the gingiva seems to have a strictly caudocranial orientation; the ability to develop collateral circulation is also limited. Ischemia was significantly increased in the stab wounds set axially over the roots of the incisors. Three and seven days later, the wound surface was considerably larger than that of papillar wounds inflicted at the same level. The attached gingiva appears to be more susceptible to injury over the roots of the lower incisors than in the neighboring papillary regions.

Adult↗
PubMed1978

The angiographic tension test in mucogingival surgery.

Attached gingiva's integrity was studied with the aid of fluorescein angiography and a standardized frenal tension test in 15 subjects aged between 19 and 41 years (9 female, 6 male) with mucogingival pathology in the region of the mandibular labial frenum. Each subject showed preoperatively gingival angiographic ischemia under 200 p frenal traction. The angiographic ischemia was in no case congruent to the clinical ischemia. One month after surgical enlargement of attached gingiva (eight grafts of palatal mucosa, seven subperiosteal vestibulum extension) both mucogingival surgery techniques successfully prevented the gingival blood circulation from showing ischemia clinically as well as angiographically under 200 p frenal traction.

Adult↗
PubMed1978

[Free mucosal grafts: a technic for obtaining grafts with a newly developed mucotome].

"Free gingival grafts--a technique for obtaining grafts using the Mucotom": A new instrument with a mechanically oscillating blade for obtaining grafts from a palatal donor site was designed. The Mucotom can be attached to a dental unit. In 27 patients aged 18 to 46 the width of the attached gingiva in the mandibular anterior and bicuspid region was widened using for each case three independent grafts of ultrathin, thin and intermediate thickness. Each graft taken with the Mucotom was measured clinically in the center and at both ends using a Mitotoyo thickness measuring gauge. The average (+/- stand. dev.) thicknesses were in millimeters: 0.37 +/- 0.09 (M I), 0.55 +/- 0.12 (M II) and 0.75 +/- 0.14 (M II) respectively. Grafts obtained by manual scalpel preparation averaged 0.96 +/- 0.15 mm. Grafts of intermediate thickness (M III) showed excellent clinical healing of the donor and the recipient site. The precise cutting of the instrument and the direct visual control of the instrument's guidance produced grafts of uniform thicknesses and without microlacerations.

Adolescent↗
PubMed1978

[Gingival injuries from toothbrush bristles].

The ability of two different toothbrush bristle ends to produce traumatic gingival abrasion was assessed in a double blind study on 15 male and 15 female young adults. Brushing was performed in a circular fashion using a modified Bass technique. An apparatus allowing continuous visual feedback of the average brushing force permitted a degree of standardisation of the system. The upper left canine and bicuspid area had to be brushed for 30 seconds with cut toothbrush bristles (CP) and with round ended toothbrush bristles (RP) respectively. A two-week interval separated the two brushing sessions. Traumatic lesions of the attached gingiva were stained with a disclosing solution, photographed and evaluated planimetrically. The "cut bristles" caused gingival abrasions 30% greater in extent than the round end bristles. The difference was not due to single brushing strokes accidentally greater for the "cut bristles". The size of the lesions was not sex-dependent.

Adult↗
PubMed1977

Blood supply of human gingiva following periodontal surgery. A fluorescein angiographic study.

This study demonstrates changes in the gingival vascular supply of humans following various periodontal surgical procedures. A special system was used to photograph circulatory changes following an i.v. injection of sodium fluorescein to visualize blood supply. The results of this study suggest that the following concepts are important in the design of periodontal flaps. 1. Flaps should be broad enough at their base to include major gingival vessels. 2. A flap's length to width ratio should not exceed 2:1. 3. Minimal tension should be produced by suturing techniques and the tissue should be managed gently during the surgical procedure. 4. Partial thickness flap preparations to cover avascular areas should not be too thin so that more blood vessels are included in them. 5. The apical portion of periodontal flaps should be full thickness when possible.

Adult↗
PubMed1977

[Transplantation of oral mucosa using a mucotome].

"Free gingival grafts--a technique for obtaining transplant tissue using a newly developed Mucotom": A new instrument for obtaining palatal soft tissue grafts was designed. It has a mechanically oscillating blade. The Mucotom is driven by the dental unit like a handpiece. The attached gingiva in the mandibular anterior region was widened in over 100 cases through a simplified surgical procedure and by taking the grafts with the Mucotom. Intermediate split thickness grafts resulted in good esthetics and function. The superior cutting ability of the instrument produced smooth grafts of uniform thickness.

Humans↗
PubMed1977

[Surface analysis of 2 composite filling materials after various methods of finishing and sealing].

The surface quality of 2 composite filling materials (Adaptic with coarse hard quartz fillers and Cosmic with fine softer glass fillers) was evaluated using profilometry, scanning electron microscopy and light reflectometry after finishing with experimental diamond discs, 3M discs, corundum discs, polishing paste and also after sealing. Plaque formation on standardized surfaces of both composites was photographically recorded in 20 subjects. The sealed surfaces and the surfaces finished by the matrix alone were approximately 10 times less rough than after finishing procedures. Under in vivo conditions they reflected the most light, for both composites. The sealer failed to cover the whole composite surface. The unfinished and sealed surfaces lost their shine 3-7 days after placement in the mouth. Decrease in reflectance was independent of mechanical oral hygiene procedures. There were no significant differences in the roughness produced by the various discs on Adaptic surfaces. Diamond discs with particle size 1-3 micrometer resulted in least surface roughness and were the only instruments not destroying the filler particles of either composite. 3M discs and the rough corundum discs caused significantly more surface roughness of the Cosmic surface. Reflectometry showed that the finishing methods unfavourably affected composite surface smoothness. Among all finishing methods polishing paste produced the highest reflection value on the Cosmic surface. Adaptic surfaces were always associated with more plaque formation than Cosmic surface after all finishing methods.

Composite Resins↗