Cases

Correction of a Reverse Smile Line – Turning back the clock!

Smile Designing doesn’t always have to be about elaborate, extensive and invasive procedures but just sometimes routine procedures done with adherence to a protocol can give astounding results, dramatically improving a patients smile and hence their overall perception about themselves. According to the principles of Smile Designing, there are three types of smiles: a consonant or ideal smile, flat smile and reverse smile. A consonant smile (Fig 1) is one where the incisal edges of the upper anteriors follow the curvature of the lower lip. A flat smile (Fig 2) is one where the incisal edges of the upper central and lateral incisors are at the same level giving the teeth a flat look compared with the lower lip curvature. A reverse smile line (Fig 3) is one where the centrals are shorter than the lateral incisors either because of attrition or trauma and the incisal edges of the upper anteriors form a reverse arc as compared to the lower lip. This kind of a smile line usually gives the person a more aged look as compared to the youthful appearance of a consonant smile. This article is a clinical case report of a correction of a reverse smile to a consonant one with simple direct composite restorations. Case Description: A 45-year-old lady walks into our office with the desire to change her smile. Photographs (extraoral and intraoral) and alginate impressions are recorded as well a detailed discussion with the patient to get an idea about her expectations. Smile analysis reveals the presence of a reverse smile line giving the patient a slightly senile appearance. Intraoral examination and history: Trauma leading to fracture of the incisal edges of 11, 21 and 12. IOPA presents with no abnormal findings and an intact lamina dura of all teeth. The teeth responded favourably to thermal pulp testing. Treatment Plan: Direct Composite restorations of 11 and 21 to restore the correct length of the incisors, thereby changing the reverse to a consonant smile line. The patient refused treatment for 12 for the time being. Polychromatic layering technique would be used for the composite resin stratification. A wax-up was made on the working model by the laboratory on which a putty index was fabricated with addition silicone material (Honigum putty, DMG). The putty index was then tried in the mouth to verify the fit and also to mark the area incisally where enamel shade composite would be added in a controlled amount to avoid possible palatal excess. Rubber dam application was carried out to provide absolute isolation required for the bonding protocol. A 2mm wide bevel was given with a diamond point and finished with finishing discs involving the enamel and dentin on the buccal surface of the fractured teeth. The palatal portion of the fracture line was only smoothened to remove any overhanging enamel. The tooth was etched with 37% Phosphoric Acid (D tech) for 20 seconds. After thorough rinsing with water and light air-drying, two coats of Universal Bonding Agent (Single Bond Universal, 3M ESPE) was applied, air thinned and photocured for 20 seconds. Enamel Shade A3 of a nanocomposite (FiltekZ350XT,3M) was adapted on the previously scored putty index, placed in position and light-cured for 20 seconds. This gave us the palatal shell on which we layered the Dentin and Body Shades (A3) sequentially. Proximal walls were created with enamel shade composite and thin mylar strips with a palatal pull-through technique. A thin final layer of enamel shade was applied and photocure. Finishing was carried out with finishing discs (Shofu Snap-on Discs) and Soflex Spirals (3M ESPE). Polishing was done with Prisma Gloss polishing paste (Dentsply) and a rubber cup . Thus the reverse smile was corrected by a simple restoration of fractured incisal edges. The patient reported back to us with a renewed sense of confidence after her smile-rejuvenation. Conclusion: Composite resins, when used with the correct protocols and understanding the material properties, can give us an excellent alternative to more extensive and expensive indirect restorations. A simplistic and minimalist approach will go a long way in preserving natural tooth structure yet giving excellent aesthetics.

Aesthetic Dentistry Smile Designing + 4 more

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This should be a slam dunk oral pathology case.

If it’s not, read up! Here we go again—94 years young and as spry as they get. Thyroid and tamoxifen (breast cancer medication) were her only drugs. The patient’s chief complaint at her recall exam: “Burning mouth, white patches under my lip ... what in the world is going on here, doctor? It’s lasted for about three weeks.” Right away I asked, “Has your diet changed? Have you had changes in your medication? Drier mouth? Have you been stressed?” No, no, yes, and especially yes. Take a look at the initial photograph. What’s the first thing that comes to your mind? Scattered, white, creamy patches in the lower anterior vestibule, each measuring approx. 3–6 mm. Now, take a look at the second picture after the white patches were easily wiped off with gauze. Note the red, thin membraned tissue? It was very tender to the touch. This diagnosis should be a slam dunk by now. Yup, you guessed it. Good ol’ pseudomembranous candidiasis, aka thrush. Let’s have a refresher on thrush. Candida albicans presents as commensals that become infective when an alteration in the immunity of the host occurs. It’s opportunistic and usually the first to take advantage of any reduction in the defense system of the host cell. Oral imbalances are common and a frequent place for these infections to occur.1 Oral clinical appearances vary; some present as white patches/lesions (some rub off, others don’t), while others appear bright red in color. C. albicans takes on various forms, each presenting slightly differently: Acute pseudomembranous candidiasis consists of creamy, loose patches of desquamative epithelium that are easily removed.1 Red tissue tender to the touch is what is painful to the patient. Atrophic (erythematous) candidiasis presents with bright red, thinned, and smooth mucosa with burning and sensitivity; it is commonly referred to as “denture sore mouth.” Chronic hyperplastic candidiasis consists of white plaques or papules against an erythematous background; it’s asymptomatic and does not rub off. A case presented earlier was diagnosed to be this form of thrush. Common oral lesions associated with C. albicans include the following: Angular cheilitis (perleche) occurs when the bilateral fissures of the mouth are overclosed and subsequently become infected; common with loss of dentition and denture wearers. Median rhomboid glossitis is an asymptomatic, elongated, erythematous patch of atrophic mucosa of the middorsal surface of the tongue due to a candidiasis infection; this is common in smokers and denture wearers. With all C. albicans infections, treatment is nystatin (as a rinse or swab), clotrimazole (commonly prescribed as a troche/lozenge), and Diflucan (fluconazole; commonly prescribed as an oral medication). Magic mouthwash, in cases where pain in present, helps manage the symptoms until the lesions are healed. (Recipe: one part viscous 2% lidocaine, one part Maalox, and one part diphenhydramine 12.5 mg/5 ml. Dosage: 1–2 tsp. 2–3x/day prn. I usually give 1–2 refills with a 150 ml bottle.) With this particular patient, it was advised that she try to reduce her stress. Dry mouth management modalities were also discussed. Additionally, scripts for Magic mouthwash and troche lozenges were dispensed. Images courtesy of the author. Refer link: https://www.dentistryiq.com/dentistry/pathology/article/14185218/this-should-be-a-slam-dunk-oral-pathology-case-if-its-not-read-up

Oral Pathology and Microbiology Oral Medicine and Radiology + 1 more

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Keratocystic Odontogenic Tumor (KCOT) of the Mandible

A 56-year-old female referred for acquisition of a CBCT for lesion in right mandible. A 12×8 cm volume was acquired showing structures from the level of the hyoid bone to the level of the floor of the nasal cavity. The TMJs were not included RADIOGRAPHIC FINDINGS The lesion in the right mandible is well-defined, low-density. It extends from the mesial aspect of impacted 48 to the level of the apex of #45 and from the apical level of the right mandibular teeth to the level of the mandibular cortex. This is causing thinning and expansion of the cortical plates and of the inferior cortex of the mandible. It too is causing root resorption of teeth 45, 46 and 47. The mandibular canal is displaced buccaly into the buccal cortical plate. Tooth 48 is impacted with its occlusal surface at the level of the alveolar crest and the apex at proximity of the mandibular cortex. The mandibular canal is in contact with the buccal surface of the middle third aspect of the root. These radiographic findings are suggestive of a benign, slow growing, locally aggressive odontogenic cyst or tumor. RADIOGRAPHIC DIFFERENTIAL DIAGNOSIS KOT Keratocystic odontogenic tumours (KCOT or KOT and previously known as odon- togenic keratocysts), are cystic benign tumors involving the mandible or maxilla and believed to arise from dental lamina. These lesions usually present in younger patients (2nd-3rd decades), are often multiple, and may be seen in either the body or ramus of the mandible (approxi- mately 70% of all KCOT) or maxilla. There may be male predilection. They are typically seen as a solitary, lucent, unilocular lesion with smooth, corticated borders. When in the mandible they usually grow along the length of the bone. In the maxilla, they expand into the maxillary sinus. They are often associated with an impacted tooth, mimicking a dentigerous cyst. KCOT mayoccasionally appear septated, making the distinction from ameloblastoma difficult. The presence of multiple KCOTs is associ- ated with Gorlin-Goltz syndrome. In the current case, the patient is a 56 Y-O female and the lesion is solitary and involving a group of teeth. It is also causing more expansion of the lingual plate than the buccal plate and is growing along the body of the mandible. AMELOBLASTOMA Ameloblastomas typically occur as hard painless lesions near the angle of the mandible in the region of the 3rd molar tooth (48 and 38). They can however occur anywhere along the alveolus ofthe mandible (80%) and maxilla (20%). When the maxilla is involved, the tumoris located in the premolar region, and can extend up in the maxillary sinus. Although benign, it is a locally aggressive neoplasm with a high rate of recurrence. Approximately 20% of cases are associated with dentigerous cysts and unerupted teeth. Radiographically, it is classically seen as a multilocualted (80%), expansile “soap-bubble” lesion, with well demarcated borders and no
matrix calcification. Occasionally erosion of the adjacent tooth roots can be seen which is highly specific. When larger it may also erode through cortex into adjacent soft tissues. In the current case, the expansion is homogeneous with no multilocular appearance. Usually, with that size of a lesion and ameloblastoma tends to be more expansile and would have caused more root resorption and displacement. CENTRAL GIANT CELL GRANULOMA A central giant cell granuloma (CGCG) (also known as giant cell reparative cyst / granuloma) occurs almost exclusively in the mandible (although cases in the skull and maxilla have been reported). It is most frequently seen in young women (F:M 2:1) 5 and typically presents in the 2nd and 3rd decades. It begins as a small lucent region, and gradually as it enlarges thin trabeculae of bone become apparent, giving it a honeycomb multilocular appearance. The lesion may demon- strate expansion, root resorption and erosion through or remodeling of the overlying cortex. In the present case, no such features are present. Similar to Ameloblastoma, with the current size of the lesion, CGCG would be more aggressive. MANAGEMENT The most likely radiographicdiagnosis is KCOT. A needleaspiration is advised to confirm KCOT. A yellowish fluid would confirm this lesion. Treatment is often marsupialisation then enucleation to avoid pathological fracture, or excision +/-aggressive curettage, however they can have a very high recurrence rate (30-60%). Refer link: https://www.dentalnews.com/2019/11/18/keratocystic-odontogenic-tumor-kcot-of-the-mandible/

Oral Pathology and Microbiology Oral Medicine and Radiology + 1 more

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Cracked Teeth

A 72-year-old male presented for a comprehensive exam with a chief complaint that the tooth on the upper right side had had a root canal done twice, but he was still in pain. He was wondering if there was a possible sinus infection. Health history included a pacemaker, Warfarin, and thyroid cancer. Testing of the upper right side was, for the most part, inconclusive, aside from some 6 mm pockets in the upper right quadrant. Radiograph was WNL . A potential sinus infection was discussed, along with the possibility of a periodontal abscess. The patient was placed on antibiotics, referred to an ENT, and had scaling and root planing done on the upper right quadrant. The report from the ENT was negative. The symptoms persisted and, in fact, started to worsen. The likelihood of a vertical root fracture was then discussed with the patient. He was referred to an endodontist who took a CBCT scan. Evaluation by the endodontist showed a very small direct, vertical 9 mm drop on the lingual with radiolucency on the lingual root in the scan about halfway down . Given the history of the double root canal, symptoms, and radiographic evidence, it was concluded that the patient had sustained a vertical root fracture on the lingual root of tooth No. 4. Prognosis was poor, and the tooth was removed with discussion regarding replacement options. This case is a classic example of how elusive diagnosing these types of teeth can be and how critical a comprehensive assessment is to produce the most accurate diagnosis.

Conservative Dentistry Endodontics

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Diagnosing what it's cracked up to be: A lesson in endodontics

There’s no one-size-fits-all approach for diagnosis/treatment of cracked or fractured teeth. Dr. Stacey Gividen presents two clinical cases to help you sort things out. Is the tooth cracked or fractured? Does it need a root canal? You’ll want to keep the decision matrix in this article as a reference tool for your endo cases. Resource for your patients >>> Cracked tooth: Types, causes, and treatments Patient: “My tooth hurts, especially when I bite down.” You: “Does the pain linger? Is it sensitive to hot and/or cold? How long has the pain been going on?” Meanwhile … tests begin and clues to the puzzle begin to come together. Diagnosis: Cracked tooth? Fractured tooth? Split tooth? Extent—unknown (or … you may have an idea, but it is subjective). So how do you decide which one it is? Now what? Root canal? Crown? What is the prognosis for treatment versus alternative replacement options? These are all questions that run through my mind when a patient presents with a cracked or fractured tooth. Sure, the test results will dictate a subsequent recommended treatment plan; however, what I’ve learned is that there is not a one-size-fits-all diagnosis and treatment for teeth such as these. Why is that? Additionally, one must consider patients who present with completely asymptomatic craze and crack lines all over their teeth. You cringe just looking at these teeth and know that there’s likely going to be a problem at some point down the road. What is the dialogue that you have with these patients? “Watch” these teeth? Recommend crowns (and often get accused of trying to bamboozle money from the patient for expensive dental work because a second opinion from another dentist suddenly renders you incompetent)? The conundrum is real. Treatment and outcome for a cracked or fractured tooth is dependent on location, direction, type, and size of the crack. Being able distinguish the difference can aid in a diagnosis that will ultimately lead to proper care and treatment. The American Association of Endodontists has classified five types of cracks in teeth: 1. Craze lines 2. Fractured cusp 3. Cracked tooth 4. Split tooth 5. Vertical fracture Refer link: https://www.dentistryiq.com/dentistry/endodontics/article/16366420/diagnosing-what-its-cracked-up-to-be-a-lesson-in-endodontics

Conservative Dentistry Endodontics

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Clinical question: What would you do—internal bleaching or crowns?

A young patient presented for a consult to consider endo/internal bleaching on nos. 9–11. An endodontist would like your perspective on the various treatment options. Here’s a question from an endodontic colleague, asking for insight from our various perspectives regarding this scenario. Take a read... Is endo/internal bleaching considered aggressive or conservative compared to full-crown coverage? How about when multiple teeth are involved? I recently had a young lady come in with multiple teeth darkened from trauma that happened years ago. It was for a consult to consider endo/internal bleaching. The patient was given the alternative for full-crown coverage on teeth nos. 9–11, with no. 9 being slightly darkened, no. 10 more so, and no. 11 in the initial stages (as compared to the normative opposing incisors). The lesion on no. 10 (which one can guess is from trauma due to the very limited restoratives; figure 1) was the main reason for being referred. Of course, there is the esthetic issue as well. So, which do you think? 1. Endodontic treatment of no. 9, 10, and 11 (with conservative accesses) with internal bleaching and lingual restorations posttreatment? Or… 2. Treat no. 10 and then do full porcelain coverage on all incisors since the shading is light enough for coverage and no show-through. Is taking a bur to the teeth too aggressive? Is it practical? Internal bleaching has its drawbacks and may not be the best definitive long-term solution the patient is looking for. Time is money; perspective is everything. State your case and why you feel that way, and I’ll post the responses for everyone to reflect on. Looking forward to the discussion! Keeping dentistry real, raw, and day-to-day... Cheers, my friends! Refer link: https://www.dentistryiq.com/dentistry/restorative-cosmetic-and-whitening/video/14203210/clinical-question-what-would-you-dointernal-bleaching-or-crowns

All Specialities Dental Materials + 1 more

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Flip-flop pathology: Same or different lesions?

Numerous radiolucent lesions in the same patient were biopsied five years apart. Based on the clinical findings, are these lesions the same or different? Case presentation and medical history A 60-year-old female presents for a new patent exam to “get established.” She had no concerns. Medical history, other than occasional social smoking and acetaminophen allergy, was insignificant. Dental history, however, was not so vanilla. Approximately five years ago, at one of her general dental appointments, she had informed her dentist that she had some tenderness in the proximity of her lower front jaw. Radiographic assessment had apparently revealed numerous radiolucent lesions in the anterior mandibular area. The patient was referred to an oral surgeon, who removed the lesions and sent them off for biopsy. The definitive diagnosis was glandular odontogenic cyst. Postsurgery, it was recommended that the patient be diligent with her recare exams, specifically radiographic follow-up as the lesions tend to recur. Clinical exam At her visit with me, the updated radiographs showed the presence of multilocular radiolucencies in the lower anterior area. Some tenderness was present but vague and very sporadic. Since there was a history to the area, it warranted another assessment and biopsy. As a side note, teeth nos. 25 and 26 had root canals on them, which I suspect were done because of the radiolucencies in the area. All other lower anterior teeth tested vital. Diagnosis and discussion The patient was referred to an oral surgeon who performed curettage on the lesions and sent the tissue off to pathology. This was the attending pathologist’s report: “…based on the morphology, I favor lateral periodontal cyst, although recurrences are more typical of the polycystic variant termed botryoid odontogenic cyst. I note that there is a reported ‘history of glandular odontogenic cyst in the same location,’ highlighting the well-known challenge differentiating lateral periodontal cyst from glandular odontogenic cyst…both lateral periodontal cyst and odontogenic keratocyst are believed to be derived from dental lamina. Clinical follow-up is recommended to ensure resolution of the radiographic abnormality.” So, there’s a flip-flop diagnosis between the patient’s original lesion and the current lesion, both of which have a similar origin. Here is some basic information about lateral periodontal cysts and glandular odontogenic cysts. Refer link: https://www.dentistryiq.com/dentistry/pathology/article/14202339/flipflop-pathology-same-or-different-lesions

Oral Medicine and Radiology Cyst and Tumors + 2 more

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An extreme case of oral herpes

A patient with a long and varied medical history presents for an extraction. Dr. Stacey Gividen discovers numerous lesions and gives her diagnosis. A 70-year-old male presents for an extraction of tooth no. 5 due to gingival-level fracture. The patient was seen two weeks prior for a limited exam to assess the break. At that time, he had received his first dose of the COVID-19 vaccination. At this dental visit, he’d had the second round of the vaccine. Medical history Over the course of the last year, the patient reported extreme stress, grinding, and subsequent breaking of teeth, of which no. 6 was extracted not nine months earlier. He received an interim partial denture/acrylic flipper to replace missing nos. 6 and 7. His blood pressure had been noted to increase over the last year, to which he had been turned away at one dental visit and advised to see his general practitioner to get his blood pressure lowered before treatment was rendered. Furthermore, this patient was recently diagnosed with type 2 diabetes. Chronic back and neck injuries, with prescriptions written for pain medications and muscle relaxants, have been his constant companion for numerous years. In addition to these issues, the patient had a history of drug abuse in the 1970s, the extent of which he claims is one of the reasons his overall health is poor. Clinical examination When we sat the patient back in the chair for delivery of local anesthetic, numerous large, irregular-bordered ulcerated lesions were noted throughout the mouth as well as the perioral area (figures 1–3). The lesions appeared crusted over and yellowish in color. Their size ranged from 5 mm to more than 15 mm. Upon inquiring, the patient stated that since his tooth broke, his tongue perpetually rubbed against the flipper, eventually causing those lesions, as well as others, throughout his mouth. He said the lesions appeared about one week prior. Given the location and duration of the lesions and the patient’s health history, it was clear that the partial was not the genesis for this pathology; stress and poor health were indeed the culprits. The diagnosis Canker sores. Fever blisters. Aphthous ulcers. Herpes type 1 (HSV-1). Yes, all of these as they are one in the same lesion. The cause Well, the ramifications of COVID-19 once again have reared their ugly head. Stress, grinding, increased blood pressure, nervous habits, poor diet, diagnosis of type 2 diabetes...put all of these into a melting pot of challenges that place strain on the body’s systems, and something has to give. In this particular scenario—due to the size and conglomerated nature of the lesions—the patient had herpetiform/aphthous major ulcers. Treatment and discussion Treatment for this patient was a prescription for acyclovir 400 mg, four to five times a day for a week. He was given instructions for care, which were primarily palliative, for the next seven to 10 days. A prescription for topical cream was denied. Here is an informative, research-based LINK that will give you a quick guide/reference/refresher on HSV-1. While the existence of canker sores has always been part of many of our patients’ lives, recent environmental stressors have played a role in an increased outbreak across the general population. This has created a need for us, as health-care providers, to up our game in prompt diagnosis, treatment, and encouragement of patient overall self-wellness. Refer link: https://www.dentistryiq.com/dentistry/pathology/article/14201524/oral-pathology-case-an-extreme-case-of-oral-herpes

Oral Medicine and Radiology Oral Mucosal Lesions + 1 more

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A 62-year-old female presented complaining of periodic symptoms from right mandibular molar area

A 62-year-old female presented complaining of periodic symptoms from right mandibular molar area Dr. Hassem Geha ([email protected]) – MS Oral and Maxillofacial Radiology University of Connecticut, School of Dental Medicine, Farmington, CT Symptoms haven’t been severe in recent times. She was previously seen by a dentist approximately 12-18 months ago due to swelling and infection in that area. At that time, she was treated with antibiotics and was told that the mandibular right wisdom tooth needs removal by a surgeon. The patient reported that she has had anesthesia of her lower right lip during flare up episodes, but this has resolved completely with no further paresthesia or anesthesia after antibiotherapy. Current clinical examination showed moderate gingival inflammation surrounding 48, and 48 was slightly tender to percussion. Caries were noted on teeth 48 and 18. Radiographic findings A panoramic radiograph and a Cone beam CT of the right mandible showing 48 and 47 and part of the mandibular ramus were available for radiographic interpretation. The viewed images show that Tooth 48 is impacted with an enlarged follicular sac. There is a well-defined, non-corticated low density extending from the level of the buccal CEJ of this tooth and extends inferiorly to the level of the apex of this tooth and loops around the apex into the lingual aspect of the tooth. This low density extends to the lingual cortical plate causing thinning and mild expansion and likely a perforation. Additional Findings • Endodontically treated 36 with widened PDL space were noted suggestive a periapical pathosis. • Missing teeth 28. Radiographic differential diagnosis Findings in the area of 48 are suggestive of an enlarged pericoronal sac that got infected and invaded the buccal PDL space of 48 and spread into the lingual area of this tooth. This is highly supported by the history of inflammation and infection as reported by the patient and the current clinical observation of tender swelling and moderate inflammation. In addition, there appears to be some occlusal trauma on 48 by 18 causing an additional stress on the PDL space of the tooth leading to a wider PDL space. Although an infected cyst can cause resorption, it is unlikely that it loops around the roots and causes resorption lingually and thinning and perforation of the lingual cortical plate with no expansion or subperiostal new bone formation. Usually, such cysts expand in a balloon-like fashion beyond the CEJ. This feature is not present in the current lesion. We clearly see a different path of expansion on the distal aspect of 48 that is not in continuity with the follicular sac. Also, while an infected cyst can cause erosion of the cortical outline of the mandibular canal, there is likelihood that the origin of the lesion is neurogenic tumour that extends from the mandibular canal and causes the resorption on the lingual aspect of 48. Such a lesion can cause thinning and perforation of the lingual cortical plate with no expansion. Also the patient has had episodes of anesthesia that can fit a neurogenic tumour. However, as these symptoms resolved, such tumour becomes an unlikely candidate. Another unlikely lesion can be a low grade muco-epidermoid carcinoma. Usually such malignant tumours tend to cause anesthesia or paresthesia that does not subside with treatment. Our differential included the following in a preferential order: 1. High likelihood for infected follicular cyst. 2. Low likelihood of Neurogenic tumour with or without superimposed infection. 3. Least likelihood of a low grade malignant tumour. Course of action Since the patient was asymptomatic, she was referred to an Oral and Maxillofacial surgeon for tooth extraction and biopsy. Surgical planning of extraction of 48 and associated requested biopsy should take into consideration the position of the mandibular canal within the lesion and the fact that the cortical outline is lost. Also, the surgical treatment should take into consideration the possible lingual perforation and the risk of injury of the lingual nerve in this area. Refer link: https://www.dentalnews.com/2019/09/26/62-year-old-female-right-mandibular-molar/

Oral Medicine and Radiology Cyst and Tumors + 2 more

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Case report of soft tissue crown lengthening

The case report that will be presented below was realized with a 980 nm diode laser. Diode laser is one of the most popular lasers because of its compact size, light weight, portable unit and relatively reduced cost while remaining efficient with beneficial effects. Its active medium is a solid state, composed from semi-conductor crystal combining Indium, Gallium and Arsenide (InGaAs) that transform the electric current into light energy. It is a modern device with the foundation of modern electronics. Depending on the clinical situation, the diode laser can be used in contact mode or non-contact mode (PBM, bleaching, desensitizing.). Cutting tissue by diode lasers occurs through photothermolysis: Chromophores in the target tissue absorb the light energy rapidly, immediate rise in temperature with subsequent denaturation of tissue protein, as well as fragmentation and vaporization of the melanin, followed by vaporization of water content. So, it is temperature rise that causes soft tissue disruption. Depending on the temperature level reached at the surgical site, soft tissue are subjected to warming, welding, coagulation, protein denaturation, drying, ablation then vaporization or carbonization10. Power settings of the diode laser device are adjustable, and the laser beam may be delivered in a constant continuous mode or in gated mode: A) With continuous mode, there is a gradual increase in the temperature then heat generation gets much faster; there is tremendous risk to get uncontrolled damage (the amount of heat generated is translated directly into the amount of collateral damage) B) With gated continuous mode, when using gated mode, there is still a rise in temperature, but the tissue has time to cool down during the thermal relaxation time, which leads to controlled collateral damage & lower thermal rise. This explains the general recommendation for laser use at low power and in gated mode for soft tissue procedures Before surgery with the diode laser, the ultra-thin lasing fiber could be initiated. This process allows capturing most of the energy (60% of the energy or more) at the end of the laser fiber and the incision is faster. This is done by tapping the laser fiber on articulating paper while the laser is energized. Usually a 300µm tip is selected for surgical gingival cutting rather than a 200µm tip, because this latter is more fragile and breakable Before cutting gingival tissue, the depth of the sulcus should be measured with a periodontal probe. The bone level should be sounded and a biological width of 2-3mm should be respected in order to avoid any further periodontal damage. During surgery, the 300µm fiber tip is placed in contact with the tissue. This gives the clinician the essential tactile feedback which is absent with some other lasers such as CO2 lasers. Excision is performed with gentle sweeping brush motions. It is important to emphasize that the laser tip does not cut like a blade, but it vaporizes tissue layer by layer at the fiber end and not on the sides, since these latter areas are protected by the collimation cladding so the energy cannot be transmitted through the sides. The correct technique is to avoid pressing on the fiber, but to simply guide it along the precise route desired, using light brush stroke to “paint away“ the amount of tissue to cut, and to let the highly directed laser energy do the work. Water irrigation with a syringe is helpful to reduce the charred layers and to cool down the tissue; high aspiration removes the dangerous laser plume.

Aesthetic Dentistry Bleaching + 1 more

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