Comparison of papilla healing following sulcular full-thickness flap and papilla base flap in endodontic surgery

AIM: To compare the loss of papilla height when using the papilla base incision (PBI) or the standard papilla mobilization incision in marginal full-thickness flap in cases with no evidence of marginal periodontitis. METHODOLOGY: Twelve healthy patients referred for surgical treatment of persisting apical periodontitis, who were free from periodontal disease and had intact interdental papillae, were included in the study. The preoperative papilla height was recorded by measuring the distance between a reproducible coronal point on the tooth and the most coronal point of the papilla. The flap design consisted of two releasing incisions connected by a horizontal incision. The marginal incision involved the complete mobilization of the entire papilla in one interproximal space, and the PBI in the other interproximal space. The PBI consisted of a shallow first incision at the base of the papilla and a second incision directed to the crestal bone creating a split thickness flap in the area of the papilla base. Further, apically, a full-thickness flap was raised. In the other interproximal space, the buccal papilla was carefully incised and elevated completely. Following flap retraction, standard root-end resection and root-end filling were performed. Flap closure was achieved with microsurgical sutures. The PBI was sutured with two to three interrupted sutures (size 7/0) and the elevated papilla was reapproximated with vertical mattress sutures, which were removed 3-5 days after the surgery. The height of the interdental papilla was evaluated preoperatively and postoperatively after 1 month and at the 3-month recall, using plaster replicas. The loss of papilla height was measured using a laser scanner. Twelve papilla-paired sites were evaluated. The results were statistically analysed using the t-test. RESULTS: Complete closure of the wound was achieved in all treated sites followed by uneventful healing in all patients. The total mobilization of the papilla resulted in loss of papilla height of 1.10 +/- 0.71 mm at 1 month and 1.25 +/- 0.81 mm at the 3-month recall. At the 3-month recall, the retraction had increased in nine sites, whereas in three sites, the loss of height had slightly diminished compared to 1 month. In contrast, after the PBI, only minor changes could be detected: 0.07 +/- 0.09 mm at 1 month and 0.10 +/- 0.15 mm at 3 months. There was a significant difference between the two incision techniques studied (P < 0.007). CONCLUSIONS: In patients with healthy marginal periodontal conditions, the PBI allows rapid and predictable recession-free healing, whereas complete mobilization of the papilla led to a marked loss of the papilla height. In aesthetically relevant areas, the use of the PBI is recommended, to avoid opening of the interproximal space, when periradicular surgical treatment is necessary.     

Comparison of long-term papilla healing following sulcular full thickness flap and papilla base flap in endodontic surgery

AIM: To compare long-term loss of papilla height when using either the papilla base incision (PBI) or the standard papilla mobilization incision in marginal full thickness flap procedures in cases with no evidence of marginal periodontitis. METHODOLOGY: Twelve healthy patients, free of periodontal disease, who had intact interdental papillae were referred for surgical treatment of persisting apical periodontitis and included in the study. The flap design consisted of two releasing incisions connected by a horizontal incision. The marginal incision involved the complete mobilization of the entire papilla in one interproximal space but in the other interproximal space the PBI was performed. Further apically a full thickness flap was raised. Following flap retraction, standard apical root-end resection and root-end filling was performed. Flap closure was achieved with microsurgical sutures. The PBI was sutured with two to three interrupted sutures (size 7/0), the elevated papilla was reapproximated with vertical mattress sutures (size 7/0), which were removed 3-5 days after the surgery. The height of the interdental papilla was evaluated preoperatively and postoperatively after 1-, 3- and 12-month recall using plaster replicas. The loss of papilla height was measured using a laser scanner. Papilla paired sites were evaluated and statistically analysed. RESULTS: Most papilla recession took place within the first month after the surgery in the complete elevation of the papilla. Further small increase in loss of papilla height resulted at 3 months. After 1 year the loss of height diminished to 0.98 +/- 0.75 mm, but there was no statistical difference between the various recall intervals. In contrast, after PBI only minor changes could be detected at all times. There was a highly significant difference between the two incision techniques for all recall appointments (P < 0.001). CONCLUSIONS: In the short as well as long-term the PBI allows predictable recession-free healing of the interdental papilla. In contrast, complete mobilization of the papilla displayed a marked loss of the papilla height in the initial healing phase although this was less evident 1 year postoperatively. In aesthetically relevant areas the use of the PBI is recommended, to avoid opening of the interproximal space, when periradicular surgical treatment is necessary.     

Papilla healing following sulcular full thickness flap in endodontic surgery

OBJECTIVE: The objective was to analyze recession of the interdental papilla in periodontally healthy situations following apical surgery using sulcular flap incisions. STUDY DESIGN: Apical surgeries were performed in 13 patients with good periodontal health. A sulcular full thickness flap involving at least 1 interproximal space was raised, using microsurgical instruments and magnification with the least possible trauma. The papillae were closed with vertical mattress sutures (polyamide 6/0) and removed after 3-5 days. The height of the interdental papilla was evaluated preoperatively and postoperatively at 1 month and 3 months using plaster casts and measured with a laser scanner. Thirteen surgical sites were compared to untreated papillae. The pairwise t test was used for statistical analysis. RESULTS: All experimental sites exhibited a significant loss of papilla height at 1 month (P <.003) and 3 months (P <.004). At 3 months retractions increased in 10 sites, while in 3 sites the loss had diminished compared to the 1-month value. CONCLUSIONS: These results suggest that the conventional sulcular flap results in considerable retraction of the papilla height after 1 month and 3 months postsurgically.     

The remodeling of human gingival tissues following gingivectomy.

A total of 30 facial gingivectomies were carried out for reduction of suprabony pockets (mean +/- S.D. preoperative pocket depth 2.8 mm +/- 0.3 mm). Remodeling of the gingival margin was monitored by clinical measurements. The following techniques were utilized: A polyvinyl stent was constructed for each surgical quadrant. This stent covered the occlusal margins of the involved teeth and contained the fixed point of reference. Preoperatively, the following measurements were taken: the distance from the fixed point to (a) the height of the free gingival margin, and (b) the base of the clinical pocket. For control purposes similar measurements were taken at the facial surface of an adjacent tooth. A standard gingivectomy to the base of the clinical pocket was then performed and a periodontal dressing was applied for 1 week. Utilizing the stent (fixed point of reference), measurements were taken of the healing margin and control sites inn the same manner as preoperatively; 1,4,8 and 12 weeks after surgery. Our findings indicate that 12 weeks after gingivectomy, the newly formed free gingival margin was located coronally to the line of incision in all cases. The mean pocket depth at 12 weeks after surgery was 0.7 mm +/- 0.2 mm. However, the mean gain in coronal marginal height was 1.2 mm +/- 0.3 mm. Thus, a clinical coronal pocket closure of about 0.5 mm seemed to have taken place at the soft tissue-tooth interface. Measurements at the nonoperated control site showed no significant variations in crevicular depth during the experimental period. We therefore conclude that the excisional reduction of a crevice to 0 mm depth was altered by gingival remodeling during the healing phase. In our experience, this remodeling took place within 3 months after surgery and clinically appeared as a limited coronal pocket closure and gain of marginal height.     

Histologic evaluation of the coronal sutures in trigonocephaly

Thirteen cases of trigonocephaly, seven isolated and six syndromic cases, were evaluated by preoperative neurologic and genetic evaluation and by radiographic evaluation (CT scans). All 13 were treated in an identical surgical manner. Specimens from the coronal sutures were obtained during surgery for histologic evaluation. All of the isolated cases, except one, showed normal coronal sutures and had a good-to-excellent result from surgery. All of the syndromic or secondary cases showed an abnormality of the coronal sutures. Four of the six cases had bad results; two required subsequent surgical procedures. It is our opinion that if a coronal suture abnormality is noted on preoperative CT scans or if preoperative evaluation demonstrates an associated syndrome or CNS malformation, the results from surgery must be guarded.     

腭侧旋转结缔组织瓣在上前牙种植修复中的临床研究

目的:探讨腭侧旋转结缔组织瓣在上颌前牙种植修复中的临床意义。方法:26例上颌前牙种植二期修复时,唇侧软组织有轻度缺损或凹陷,在牙槽嵴顶种植体位置作“H形”切口,形成颊侧带蒂粘骨膜瓣尖端带有腭侧的结缔组织瓣。将腭侧结缔组织旋转折叠,插入颊侧龈瓣内侧。愈合基台挤压龈乳头瓣诱导种植体周围龈乳头成形。2~4周后上部冠修复。6月后测量腭侧旋转结缔组织瓣移植前后唇侧牙龈丰满度等变化。结果:所有种植体均稳固,唇侧龈缘基本对称,手术前后唇侧软组织丰满度差为(1.10±0.45) mm,外形有明显改善,龈乳头顶到牙冠邻面接触点的距离为(2.05±0.76) mm。结论:腭侧旋转结缔组织瓣手术方法简单、易行,针对唇侧软组织缺损较少的部位可以较好地改善上颌前牙美学区种植义齿的软组织凹陷问题。     

Influence of flap design on periodontal healing of second molars after extraction of impacted mandibular third molars

OBJECTIVE: The aim of this study was to compare the influence of two mucoperiosteal flaps on periodontal healing of adjacent second molars after extraction of impacted mandibular third molars. STUDY DESIGN: An envelope incision with a releasing incision anterior to the second molar (3-cornered flap) was used on one side and a Szmyd flap on the other side in 14 patients with bilateral impaction of mandibular third molars. The periodontal health of the second molars was evaluated before surgery and at 3 and 6 months postoperatively. A William's periodontal probe was used to measure the pocket depth, clinical attachment level, and bone level of the buccal and mesial surfaces of the second molars. The postoperative measurements were analyzed by using analysis of covariance, with the covariables being the preoperative measurements and variation factors being the type of flap used, the surface measured, and the time since the procedure. RESULTS: No statistically significant differences were found in comparing measurements of probing depth, clinical attachment level, or bone level for the 2 types of flap used or the 2 surfaces measured. However, there was a statistically significant increase in all 3 measurements from the 3-month to the 6-month postoperative time. CONCLUSION: Independent of the design of the mucoperiosteal flap used in extracting an impacted mandibular third molar, the periodontal condition of the adjacent second molar worsened from 3 to 6 months, although it remained within normal values.     

Correction of coronal suture synostosis using suture and dura mater allografts in rabbits with familial craniosynostosis.

OBJECTIVE: Resynostosis following surgical correction of craniosynostosis is a common clinical correlate. Recent studies suggest that the dura mater is necessary to maintain suture patency. It has also been hypothesized that dura mater from synostotic individuals may provide aberrant biochemical signals to the osteogenic fronts of the calvaria, which result in premature suture fusion and subsequent resynostosis following surgery. This study was designed to test this hypothesis by surgically manipulating the coronal suture and dura mater in rabbits with familial craniosynostosis to prevent postsurgical resynostosis. DESIGN: Craniofacial growth and histomorphometric data were collected from 129 rabbits: 72 normal controls and 57 rabbits with bilateral coronal suture synostosis (15 unoperated on controls; 13 surgical controls; 9 dura mater transplant only; 10 suture transplant only; and 10 suture and dura mater transplant). At 10 days of age, all rabbits had radiopaque amalgam markers placed on either side of the coronal, frontonasal, and anterior lambdoidal sutures. At 25 days of age, 42 synostosed rabbits had a 3 to 5-mm wide coronal suturectomy. Coronal sutures and/or underlying dura mater allografts were harvested from same-aged, wild-type, isohistogenic control rabbits and transplanted onto the dura mater of synostosed host rabbits. Serial radiographs were taken at 10, 25, 42, and 84 days of age, and the suturectomy sites were harvested at 84 days of age in 44 rabbits and serially sectioned for histomorphometric examination. RESULTS: Results revealed that cranial vault growth was significantly (p < .05) improved following surgical release of the fused coronal suture compared with synostosed rabbits who were not operated on but was still significantly different (p < .05) from that of normal control rabbits. By 84 days of age, significant (p < .05) differences were noted in calvarial suture marker separation, cranial vault shape indices, and cranial base angles between rabbits with and without dura mater allografts, probably as a result of resynostosis of the suturectomy site or suture-only allografts. Qualitative histological examination revealed that at 84 days of age rabbits with suture and dura allografts had patent coronal sutures, suture-only allografts had fused coronal sutures with extensive endosteal hyperostosis, dura mater-only allografts had some new bone in the suturectomy site that resembled rudimentary osteogenic fronts, and suturectomy controls had extensive endosteal bone formation and resynostosis of the suturectomy site. Significantly (p < .05) more bone was found in the suturectomy sites of rabbits without dura mater allografts compared with rabbits with dura mater allografts. CONCLUSIONS: Results support the initial hypothesis that normal dura mater allografts will maintain suture or suturectomy site patency and allow unrestricted craniofacial growth. However, it is still unclear whether the dura mater from normal rabbits was providing biochemical signals to the transplanted sutures or suturectomy sites or simply acting as a barrier to prevent abnormal biochemical signals from the dura mater of synostosed rabbits from reaching the calvaria. The clinical and therapeutic implications of these procedures are discussed.     

Enamel matrix proteins in the treatment of periodontal sites with horizontal type of bone loss

OBJECTIVES: The present study aims to assess the clinical and radiographic outcome of horizontal type of bone loss over a period of 8 months following periodontal surgery with adjunctive use of enamel matrix proteins (EMP). MATERIALS AND METHODS: Twenty patients, who received nonsurgical periodontal therapy and had radiographic horizontal bone loss with an associated probing depth (PD) of > or =4 mm at the maxillary incisor/canine segment, were included. One side of the selected segment divided by the mid-sagittal plane was treated with EMP as part of a crevicular flap. The other side was treated either with a similar intracrevicular (ICI) or a reverse bevel incision (RBI) as part of a conventional flap debridement. Therefore, patients were divided into two groups of 10 patients according to the type of incision performed on the control side. The analysis was based on a classification of two severity groups according to preoperative PD, with the patient's means of measurements for each treatment being the experimental units for the statistical analysis. RESULTS: For pockets of 4-6 mm, EMP treatment was significantly better than the ICI/flap debridement in terms of PD reduction (p<0.001), relative attachment level (RAL) gain (p<0.001) and recession (REC) (p<0.05). Although sites exposed to EMP treatment exhibited significantly greater RAL gain than RBI/flap debridement sites (p<0.01), both treatments resulted in equally effective PD reduction. Less REC occurred with EMP application than with ICI-RBI/flap debridement (p<0.05). Treatment of shallow sites by the conventional flap with both incisions resulted in a tendency for loss of attachment whereas EMP treatment maintained the attachment levels. No significant difference in the degree of probing and radiographic bone levels was found between the treatments. CONCLUSION: EMP treatment showed better clinical improvements as compared to the conventional flap debridement performed with two different incisions. Clinical improvements were more pronounced at periodontal sites with deep, rather than shallow, periodontal pockets. The results of this study provided an important preliminary base for further clinical and histologic studies.     

Tissue concentration and localization of tetracycline following site-specific tetracycline fiber therapy.

The primary objective of this study was to evaluate the concentration and location of tetracycline hydrochloride in tissue adjacent to periodontal pockets treated with a tetracycline impregnated fiber. A secondary objective was to determine if the presurgical placement of fibers had any adverse effects on healing following periodontal surgery. The study population consisted of 10 patients with at least 2 pockets in both maxillary quadrants of > or = 5 mm in depth and exhibiting bleeding on probing. After an initial scaling and root planing, placebo or tetracycline fibers were randomly assigned by quadrant to 2 non-adjacent pockets. Fibers were removed at the time of surgery; i.e., day 8, and periodontal surgery was performed utilizing a flap incision that allowed biopsy of 1 interdental papilla from each of the 2 test sites in each quadrant. One biopsy was analyzed for tetracycline concentrations by high performance liquid chromatography (HPLC). The second biopsy was examined by both light and ultraviolet fluorescence microscopy to determine the location of residual tetracycline and the intensity of inflammatory cell infiltrates. Results showed that the tissue concentration of the antibiotic in tetracycline treated sites was 64.4 +/- 7.01 ng/mg (ng of tetracycline/mg tissue weight) which corresponds to 43 micrograms of tetracycline and was below levels of accurate measurement in placebo treated sites. Tetracycline tissue concentrations corresponded to the ultraviolet fluorescence microscopy with a Pearson correlation coefficient of r = 0.92. Tetracycline fluorescence was noted in the soft tissue wall ranging from 1 to 20 microns.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fate of pocket epithelium in an apically positioned flap

The fate of periodontal pocket epithelium when sulcular incisions are used in apically positioned flap surgery was investigated by serial histology. Human subjects received apically positioned flap segments on the facial aspect of anterior teeth timed to give 1, 3, 5, 7, 21 and 35 days of healing on the day of extraction. Companion surgeries for comparison consisted of similar flaps, but utilized an inverse bevel primary incision. Assessment of the sulcular incision specimens revealed that epithelial degeneration and dissolution occurred within 7 days and resulted in a collagen-to-collagen attachment of the periodontal flap to the alveolar bone. The inverse bevel incision was consistently effective in removing the pocket epithelium and resulted in healing by a connective tissue union of the flap to the alveolar bone. By 21 days of healing, the 2 surgical methods were indistinguishable histologically. On the basis of this investigation, it is suggested that the inverse bevel primary incision traditionally advocated for apically positioned flap surgeries may be replaced by the more rapid and simple sulcular incision as the preferred technique.     

Elimination of epithelium from healing postsurgical periodontal wounds by ultra-low temperature. Initial observations

Prevention of epithelial migration into healing postsurgical periodontal wounds may enhance connective tissue attachment. This study attempted to destroy selectively epithelium on gingival flap surfaces by ultra-low temperature. Sixteen sites in four young adult cats received subcrestal reverse bevel incisions followed by sulcular incisions. Full thickness periodontal flaps were reflected, the remaining supracrestal soft tissue surrounding the teeth was removed, and exposed root surfaces were curetted. Narrow zones measuring about 4 mm along the coronal margins of the flaps were exposed to ultra-low temperature for 5 seconds using a gas expansion cryoprobe cooled to -81 degrees C and placed at the oral gingival aspects of the flaps. Flaps were then repositioned and sutured. Control sites were sham-operated with the cryoprobe kept at room temperature (25 degrees C). Gingival biopsies were taken at 1 hour and at 2, 4, 8 and 12 days following surgery. Microscopically, 1-hour postfreezing and control specimens appeared similar. At 2 and 4 days, large surface areas of corium were denuded of epithelium or were covered by necrotic debris. Mild inflammatory responses were noted within the corium. At 8 days, the epithelium almost completely covered the corium with some initial formation of crevicular epithelium. After 12 days, crevicular epithelium was observed in all tissue sections. No significant morphologic damage to the connective tissue was noted at any time. We, therefore, concluded that low cryodoses can effectively destroy oral gingival epithelium without causing significant morphologic damage to the underlying lamina propria at this level of observation.     

Comparison between hockey stick and reversed hockey stick incision: gently curved single linear neck incisions for oral cancer.

Hockey stick incision (HSI) and reversed-HSI are known to be useful incisions for lymph node dissections of the neck. Both are gently curved single linear incisions without three-point suture line junctions, but are different at the base of the skin flap. The HSI allows the elevation of a superiorly-based single cervical skin flap and the reversed-HSI allows for an inferiorly-based flap. We compared the viability of the skin flaps, exposure of the operation field and cosmetic results to evaluate the characteristics of each incision. HSI appeared to be the suitable incision for radical neck dissection due to adequate exposure of the operation field while rendering excellent cosmetic results. Reversed-HSI was applied in combination with block resection of parts of the oral cavity because it provided much better exposure of the operation field than HSI, while still achieving acceptable cosmetic results. Using this technique, a small area of marginal necrosis was occasionally seen at the apex of the skin flap due to poor blood supply.     

The simplified papilla preservation flap. A novel surgical approach for the management of soft tissues in regenerative procedures

A novel surgical procedure specifically designed to access interdental spaces in the regenerative treatment of deep intrabony defects is presented. This procedure (simplified papilla preservation flap, SPPF) was designed to provide surgical access to interproximal bony defects while preserving interdental soft tissues, even in narrow interdental spaces and posterior teeth. A modified mattress suture allows coronal positioning of the buccal flap and primary closure of the interdental space without tension. The modified mattress suture minimizes the collapse of the membrane into the defect. An experimental population of 18 patients in good general health who presented with one intrabony defect each was selected for this clinical study. The application of the SPPF in combination with bioresorbable membranes resulted in clinical attachment level (CAL) gains of 4.9 +/- 1.8 mm at 1 year. The difference between baseline CAL and 1 year CAL was highly clinically and statistically significant. The residual pockets at 1 year measured 3.6 +/- 1.2 mm. A slight increase in gingival recession was noted. Primary closure of the flap in the interdental space over the membrane was obtained in 100% of the cases after completion of surgery and maintained in 67% of the cases during the healing period. The application of SPPF in combination with bioresorbable barrier membranes allowed primary closure of the interdental space in most of the treated sites and resulted in consistent CAL gains at 1 year.     

Histologic evaluation of periodontal healing in humans following regenerative therapy with enamel matrix derivative. A 10-case series

BACKGROUND: Enamel matrix derivative (EMD) has been developed as a stimulus of periodontal regeneration. Human histology following its use has not been evaluated on pathologically altered root surfaces. METHODS: Ten intrabony defects in 8 patients were evaluated at 2 centers. Teeth with advanced adult periodontitis that were treatment planned for extraction were treated with sulcular incisions; full-thickness flap reflection; debridement of granulomatous tissue from the defect; placement of a notch in the root at the apical extent of calculus; mechanical root planing; conditioning with citric acid; application of EMD; wound closure with sutures; and placement of a periodontal dressing. Biweekly to monthly recalls were made until removal of small block section biopsies at about 6 months. The biopsies were fixed, decalcified, step-serial sectioned at 6 microns to 8 microns, and stained with hematoxylin and eosin or Masson's trichrome. RESULTS: Histologic evaluation of the region coronal to the base of the calculus notch showed evidence of regeneration (new cementum, new bone, and new periodontal ligament) in 3 specimens, new attachment (connective tissue attachment/adhesion only) in 3 specimens, and a long junctional epithelium in 4 specimens. No evidence of root resorption, ankylosis, or untoward inflammation was seen. CONCLUSIONS: The results of this study fulfill the proof of principle that use of EMD can result in periodontal regeneration on previously diseased root surfaces in humans, but on an inconsistent basis.     

Flap design and the LeFort III osteotomy: Blood flow investigation

The effect on local blood flow of flap design in a LeFort III osteotomy was examined in this study. The radioactive microsphere technique was used to make serial flow determinations in two groups of macaque monkeys. The use of seven skin and mucosal incisions was compared with a coronal flap procedure. Significant blood flow reductions to the midface segment were measured when a coronal incision was the sole access in performance of the osteotomies. The findings indicate that the multiple incision approach is more biologically sound than the coronal incision approach in the LeFort III osteotomy. Important information about the surgical techniques can be determined from the data and applied to a more successful performance of the LeFort III osteotomy.     

The combined coronal–transconjunctival approach: an innovative surgical access for orbital exenteration in craniofacial resection

Malignant tumours arising in the paranasal sinuses or maxilla usually spread to the surrounding regions. The skull base and the anterior cranial fossa are frequently affected as well. When the resection of a tumour involves an orbital exenteration, a transconjunctival-perilimbic incision can be added to a coronal approach in order to preserve the eyelids and the conjunctiva, avoiding cutaneous midfacial incisions. Patients with a diagnosis of malignant tumour affecting the orbit, upper jaw, paranasal sinuses, and/or anterior skull base were eligible for this technique. Tumoural invasion of the eyelids, conjunctiva, lacrimal system, or surrounding skin was considered a contraindication for this technique. A retrospective study of the clinical records was performed and age, type of tumour, location, and reconstructive technique were evaluated. Eight patients referred to the study department between 2015 and 2019 were selected. All patients underwent craniofacial surgery and orbital exenteration. The transconjunctival-perilimbic approach was combined with a coronal incision in all cases. In our experience, the transconjunctival-perilimbic approach to orbital exenteration proposed in this paper can be used successfully in skull base surgery. Combined with a coronal and transmandibular approach, it allows wide access to the facial skeleton/anterior skull base while avoiding skin incisions in the midface.     

Changes of periodontal parameters following apical surgery: a prospective clinical study of three incision techniques

AIM: To evaluate periodontal changes following apical surgery, and to relate changes to the type of incision and to the type of restoration present at the gingival margin (GM). METHODOLOGY: Periodontal parameters [probing depth (PD), level of GM and clinical attachment, plaque and bleeding indices] were recorded at baseline and 1 year following apical surgery. The periodontal changes were calculated and assessed with respect to the incision technique (intrasulcular incision, papilla base incision and submarginal incision), as well as to the presence and type of a restoration margin in contact with the gingiva. RESULTS: One hundred and eighty-four teeth could be evaluated. No significant differences between the three incision techniques were found regarding changes in PDs and plaque index over time. However, significant differences between the intrasulcular and submarginal incisions were found for changes in levels of GM and clinical attachment. For example, with the intrasulcular incision, there was a mean recession of 0.42 mm at buccal sites, whereas using the submarginal incision there was a gain of 0.05 mm. No statistically significant influence could be demonstrated for the presence and type of restoration margins, or the smoking habit of the patient. CONCLUSION: The type of incision was found to affect changes significantly in periodontal parameters within an observation period of 1 year following apical surgery, whereas the restoration margin and smoking habit did not prove to have any significant effect.     

Evaluation of guided tissue regeneration in Class II furcation defects. A clinical re-entry study

Twelve patients with two comparable furcation Class II lesions in lower molars were included in this study. After adequate presurgical preparation and pertinent clinical measurements, the areas were treated with full thickness flaps and thorough debridement and scaling and planing of the root surfaces. One of the defects was randomly selected to be covered with Gore-Tex periodontal material, held in place by sling sutures of expanded polytetrafluoroethylene. On both sites the flaps were positioned slightly coronal to their original level and sutured. After 6 months both sites were re-entered surgically and remeasured. The test sites showed a statistically significant reduction in pocket depth and gain in attachment levels while the controls had not changed from preoperative levels. No changes in bone levels were detected in test or control sites. However, because of the large variability in the measurements, and the short period of observation, there may be differences in bony changes between the two therapies. Studies with larger groups, more accurate methods, and longer time intervals are needed to better evaluate the effects of barrier membranes in periodontal healing.     

A sheep cadaver model for demonstration and training periodontal surgical methods

There is lack of data on the suitability of animal cadaver models for teaching purposes in dentistry. Here, we describe a model suitable for training for several periodontal surgical methods. Mandibles of freshly slaughtered Australian adult sheep and lambs were examined. Periodontal probing depths (PPDs) were measured at six sites of every tooth present. The following surgical techniques were critically analyzed: access flap with interrupted, continuous sutures; apically repositioned flap with periosteal sutures; coronally advanced flap with sling suture; gingivectomy; and distal wedge procedure. Probing depths were highest in the buccal furcation area of 1st and 2nd molars, where deep intrabony lesions were present in certain samples from adult sheep. Another area of increased probing depth was lingual to canines and incisors. Here, a pronounced lower dental pad of fibrous tissue was present. In this area, gingivectomy could always be accomplished. Fibrous tissue was also found distal to the most posterior molar, where the distal wedge procedure could be exercised. Access flaps and apically repositioned flaps could be performed particularly at premolars. Here, interrupted or continuous sutures were possible. Because of tight interdental contact areas, needle insertion was difficult at molars. After periosteal dissection, labial flaps at anterior teeth could easily be advanced coronally and sutured with sling sutures. Because of the teeth's dimensions and tight contact areas, simulation of more advanced techniques such as papilla preservation flaps was not possible. The sheep mandible seems to be a feasible training model for the demonstration and exercise of various periodontal surgical techniques for the treatment of periodontitis.