BIOLASE (BIOL) 424B3 Prospectus supplement

Filed pursuant to Rule 424(b)(3)

Registration Statement No. 333-266673

PROSPECTUS

BIOLASE, INC.

1,405,405 SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE OF OUTSTANDING WARRANTS

This prospectus relates to the possible resale of up to 1,405,405 shares of our common stock, $0.001 par value per share (“Common Stock”) that may be issued upon the exercise of certain warrants at an exercise price of $4.625 per share (the “Warrants) by the selling stockholders identified in this prospectus or in supplements to this prospectus. The Warrants were issued to the selling stockholders in connection with a previously disclosed June 27, 2022 private placement.

We are not offering any shares of our Common Stock for sale under this prospectus and we will not receive any part of the proceeds from sales of the shares of our Common Stock by the selling stockholders; however, we will receive proceeds upon the exercise of outstanding Warrants for shares of our Common Stock covered by this prospectus if the Warrants are exercised for cash. We will bear all expenses of registration incurred in connection with this offering, but all selling and other expenses incurred by the selling stockholders will be borne by them.

Our Common Stock trades on The Nasdaq Capital Market under the symbol “BIOL.” On August 12, 2022, the last reported sale price for our Common Stock on The Nasdaq Capital Market was $5.21 per share.

Investing in our securities involves substantial risks. You should consider the “Risk Factors” on page 3 of this prospectus, in the documents that are incorporated by reference into this prospectus and, if applicable, in risk factors described in any accompanying prospectus supplement before buying any of our securities.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE ADEQUACY OR ACCURACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The date of this prospectus is August 19, 2022.

TABLE OF CONTENTS

PROSPECTUS SUMMARY	1
THE OFFERING	2
RISK FACTORS	3
CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING STATEMENTS	3
USE OF PROCEEDS	6
DESCRIPTION OF CAPITAL STOCK	6
SELLING STOCKHOLDERS	10
PLAN OF DISTRIBUTION	11
LEGAL MATTERS	13
EXPERTS	13
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE	14
WHERE YOU CAN FIND MORE INFORMATION	14

The exhibits to the registration statement contain the full text of certain contracts and other important documents we have summarized in this prospectus. Since these summaries may not contain all the information that you may find important in deciding whether to purchase our Common Stock, you should review the full text of these documents. The registration statement and the exhibits can be obtained from the Securities Exchange Commission (“SEC”) as indicated under the sections entitled “Incorporation of Certain Information by Reference” and “Where You Can Find More Information.”

You should rely only on the information that we have provided or incorporated by reference in this prospectus, any applicable prospectus supplement, any related free writing prospectus that we may authorize to be provided to you and the other information to which we refer you. Neither we nor the selling stockholders have authorized anyone to provide you with different or additional information. Neither we nor the selling stockholders are making an offer to sell our Common Stock in any jurisdiction where the offer or sale thereof is not permitted. You should not assume that the information appearing in this prospectus or any applicable prospectus supplement or the documents incorporated by reference herein or therein is accurate as of any date other than their respective dates. Our business, financial condition, results of operations and prospects may have changed since those dates. You should read carefully the entirety of this prospectus and any applicable prospectus supplement, as well as the documents incorporated by reference in this prospectus and any applicable prospectus supplement, before making an investment decision.

We urge you to carefully read this prospectus and any applicable prospectus supplement, together with the information incorporated in this prospectus by reference as described under the heading “Where You Can Find Additional Information.”

In this prospectus, unless otherwise specified or the context requires otherwise, we use the terms “Company,” “we,” “us” and “our” or similar references to refer to BIOLASE, Inc., a Delaware corporation, together with its consolidated subsidiaries.

PROSPECTUS SUMMARY

This summary highlights certain information contained in greater detail elsewhere in this prospectus or incorporated by reference into this prospectus. This summary is not complete and does not contain all of the information that you should consider before deciding whether to invest in our securities. You should carefully read this prospectus, any accompanying prospectus supplements, any related free writing prospectus that we have authorized for use in connection with the offering and the documents incorporated by reference in this prospectus and in any accompanying prospectus supplement, including the information referred to under the heading “Risk Factors” in this prospectus, under the heading “Risk Factors” contained in the applicable prospectus supplement and in the documents incorporated by reference into this prospectus and any prospectus supplement.

Our Company

We are a leading provider of advanced laser systems for the dental industry. We develop, manufacture, market and sell laser systems that provide significant benefits for dental practitioners and their patients. Our proprietary systems allow dentists, periodontists, endodontists, pediatric dentists, oral surgeons and other dental specialists to perform a broad range of minimally invasive dental procedures, including cosmetic, restorative and complex surgical applications. Our laser systems are designed to provide clinically superior results for many types of dental procedures compared to those achieved with drills, scalpels and other conventional instruments. Potential patient benefits include less pain, fewer shots, faster healing, decreased fear and anxiety and fewer appointments. Potential practitioner benefits include improved patient care and the ability to perform a higher volume and wider variety of procedures and generate more patient referrals. For additional information about our Company, please refer to other documents we have filed with the SEC and that are incorporated by reference into this prospectus, as listed under the heading “Incorporation of Certain Information by Reference.”

Our principal executive offices are located at 27042 Towne Centre Drive, Suite 270, Lake Forest, California 92610. Our telephone number is (949) 361-1200. Additional information can be found on our website, at www.biolase.com, and in our periodic and current reports filed with the SEC. Copies of our current and periodic reports filed with the SEC are available at the SEC’s website at www.sec.gov and our website at ir.biolase.com/sec-filings. No portion of our website is incorporated by reference into this prospectus.

Description of the Warrant Shares

On June 27, 2022, in a private placement, the selling stockholders purchased Warrants to acquire up to an aggregate of 1,405,405 shares of our Common Stock at an exercise price of $4.625 per share. The Warrants are exercisable for a period of five and a half years commencing on June 27, 2022.

We completed the private placement in reliance on an exemption to registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), and the rules promulgated thereunder. Each of the selling stockholders is either a “qualified institutional buyer” as defined in Rule 144A(a) under the Securities Act or an “accredited investor” as defined in Rule 501(a) under the Securities Act.

In accordance with the registration rights that we granted in the securities purchase agreement entered into in connection with the private placement, we are registering for resale by the selling stockholders the shares of our Common Stock that may be issued upon exercise of the Warrants issued in the private placement.

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THE OFFERING

Common Stock offered by the selling stockholders	1,405,405 shares of our Common Stock issuable upon exercise of Warrants at an exercise price of $4.625 per share of Common Stock
Common Stock to be outstanding after the offering	8,260,176 shares
Use of proceeds	We will receive no proceeds from the sale of the shares of our Common Stock issuable upon exercise of the Warrants. We may, however, receive proceeds upon the cash exercise, if any, of the Warrants held by the selling stockholders. If the Warrants as of the date of this prospectus were to be cash exercised in full, we would receive gross cash proceeds of approximately $6.5 million. The Warrants are exercisable at any time. We intend to use any net proceeds received upon exercise of any of the Warrants for working capital and for general corporate purposes. See “Use of Proceeds” for a more complete description of the intended use of proceeds from the exercise of the Warrants.
Risk factors	An investment in our Common Stock involves substantial risks. You should read carefully the “Risk Factors” included and incorporated by reference in this prospectus, including the risk factors incorporated by reference from our filings with the SEC.
Nasdaq Capital Market symbol for Common Stock	“BIOL”

The number of shares of our Common Stock that will be outstanding immediately after this offering as shown above is based on 6,854,771 shares outstanding as of August 1, 2022, plus 1,405,405 shares of our Common Stock issuable upon the exercise of the Warrants, and excludes (vested and unvested):

• 71,711 shares of our Common Stock issuable upon the exercise of stock options, with a weighted-average exercise price of $62.23 per share;

• 431,138 shares of our Common Stock issuable upon the settlement of outstanding restricted stock units;

• 688,415 shares of our Common Stock issuable upon the exercise of outstanding warrants (other than the Warrants and prefunded warrants), with a weighted-average exercise price of $10.62 per share;

• 423,990 shares of our Common Stock that may be issued, at the sole discretion of our board of directors, upon the settlement of outstanding phantom restricted stock units, which may also be settled, at the sole discretion of our board of directors, in cash;

• 38,692 shares of our Common Stock that may be issued, at the sole discretion of our board of directors, upon the settlement of outstanding stock appreciation rights, which may also be settled, at the sole discretion of our board of directors, in cash; and

• 726,660 shares of Common Stock issuable upon exercise of outstanding prefunded warrants, with an exercise price of $0.001 per share.

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RISK FACTORS

We face a variety of significant and diverse risks, many of which are inherent in our business. You should carefully consider the risks described under the caption “Risk Factors” in our most recent annual report on Form 10-K, subsequent quarterly reports on Form 10-Q and other filings we make with the SEC pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), incorporated by reference in this prospectus, before making an investment decision. Additional risk factors may be included in any prospectus supplements relating to the offering of securities described in this prospectus. The occurrence of any of those risks could materially and adversely affect our business, prospects, financial condition, results of operations or cash flow. Other risks and uncertainties that we do not now consider to be material or of which we are not now aware may become important factors that affect us in the future. Please also read carefully the section below entitled “Cautionary Statements Regarding Forward-Looking Statements.”

CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, any prospectus supplement and the documents that we incorporate herein or therein by reference contain “forward-looking statements,” as defined in Section 27A of the Securities Act and Section 21E of the Exchange Act that involve risks, uncertainties and assumptions, which could cause actual results to differ materially from management’s expectations. Such forward-looking statements include statements, predictions or expectations regarding market opportunities, our plans for future products and services and enhancements of existing products and services, future market growth and our anticipated growth strategies, future demand for improved dental care and dental laser equipment, expansion of our international operations, compliance with laws and regulatory requirements, the impact of cost-saving measures and future decreases in expenses, statements regarding the effects of seasonality on revenue, anticipated cash needs, capital requirements and capital expenditures, needs for additional financing, anticipated use of proceeds from debt or equity financing, use of working capital, plans to explore potential collaborations, potential acquisitions of products and technologies, effects of engineering and development efforts, plans to expand our field sales force, the development of distributor relationships, our ability to attract customers, the adequacy of our facilities, products and solutions from competitors, our ability to maintain product quality standards, protection of patents and other technology, the ability of third-party payers to pay for costs of our products, limitations on capital expenditures, critical accounting policies and the impact of recent accounting pronouncements, recording tax benefits or other financial items in the future, plans, strategies, expectations or objectives of management for future operations, our financial condition or prospects and any other statement that is not historical fact. Forward-looking statements are identified by the use of words such as “may,” “might,” “will,” “intend,” “should,” “could,” “can,” “would,” “continue,” “expect,” “believe,” “anticipate,” “estimate,” “predict,” “outlook,” “potential,” “plan,” “seek,” and similar expressions and variations or the negatives of these terms or other comparable terminology.

Forward-looking statements are based on the expectations, estimates, projections, beliefs and assumptions of our management based on information available to management as of the date on which such forward-looking statement was made, all of which are subject to change. Forward-looking statements are subject to risks, uncertainties and other factors that are difficult to predict and could cause actual results to differ materially from those stated or implied by our forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to:

• the effects of the COVID-19 pandemic and the actions taken to contain it;

• losses that we have experienced for each of the past three years;

• global economic uncertainty and volatility in financial markets;

• inability to raise additional capital on terms acceptable to us;

• our relationships with, and the efforts of, third-party distributors;

• failure in our efforts to train dental practitioners or to overcome the hesitation of dentists and patients to adopt laser technologies;

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• inconsistencies between future data and our clinical results;

• competition from other companies, including those with greater resources;

• our inability to successfully develop and commercialize enhanced or new products that remain competitive with products or alternative technologies developed by others;

• the inability of our customers to obtain third-party reimbursement for their use of our products; limitations on our ability to use net operating loss carryforwards;

• problems in manufacturing our products;

• warranty obligations if our products are defective;

• adverse publicity regarding our technology or products;

• adverse events to our patients during the use of our products, regardless of whether caused by our products;

• issues with our suppliers, including the failure of our suppliers to supply us with a sufficient amount or adequate quality of materials;

• rapidly changing standards and competing technologies;

• our inability to effectively manage and implement our growth strategies;

• risks associated with operating in international markets, including potential liabilities under the Foreign Corrupt Practices Act;

• breaches of our information technology systems;

• seasonality;

• litigation, including the failure of our insurance policies to cover certain expenses relating to litigation and our inability to reach a final settlement related to certain litigation;

• disruptions to our operations at our primary manufacturing facility;

• loss of our key management personnel or our inability to attract or retain qualified personnel;

• risks and uncertainties relating to acquisitions, including difficulties integrating acquired businesses successfully into our existing operations and risks of discovering previously undisclosed liabilities;

• failure to meet covenants in the Credit Agreement, dated as of November 9, 2018, (as amended from time to time, the “Credit Agreement”), by and between BIOLASE and SWK Funding, LLC;

• interest rate risk, which could result in higher expense in the event of interest rate increases;

• obligations to make debt payments under the Credit Agreement;

• risks of foreclosure triggered by an event of default under the Credit Agreement;

• failure to comply with the reporting obligations of the Exchange Act and Section 404 of the Sarbanes-Oxley Act of 2002, as amended, or maintain adequate internal control over financial reporting;

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• climate change initiatives;

• failure of our intellectual property rights to adequately protect our technologies and potential third-party claims that our products infringe their intellectual property rights;

• changes in government regulation or the inability to obtain or maintain necessary governmental approvals;

• our failure to comply with existing or new laws and regulations, including fraud and abuse and health information privacy and securities laws;

• changes in the regulatory requirements of the Food and Drug Administration (“FDA”) applicable to laser products, dental devices or both;

• recall or other regulatory action concerning our products after receiving FDA clearance or approval;

• our failure to comply with continued listing requirements of the NASDAQ Capital Market; and

• risks relating to ownership of our Common Stock, including high volatility and dilution.

Further information about factors that could materially affect the Company, including our results of operations, financial condition and stock price, is contained under the heading “Risk Factors” in this prospectus, under the heading “Risk Factors” contained in the applicable prospectus supplement and in the documents incorporated by reference into this prospectus and any prospectus supplement. Except as required by law, we undertake no obligation to revise or update any forward-looking statements to reflect changed assumptions, the occurrence of anticipated or unanticipated events, new information, changes to future results over time or otherwise.

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USE OF PROCEEDS

Unless otherwise indicated in the applicable prospectus supplement, we will use the net proceeds from the cash exercise, if any, of the Warrants held by the selling stockholders for working capital, including new product development, launch and subsequent scale-ups, as well as other general corporate purposes. The timing and amount of our actual expenditures will be based on many factors, including cash flows from operations and the anticipated growth of our business. As a result, unless otherwise indicated in the applicable prospectus supplement, our management will have broad discretion to allocate the net proceeds of the offerings. Pending their ultimate use, we intend to invest the net proceeds in short-term, investment-grade, interest-bearing instruments.

DESCRIPTION OF CAPITAL STOCK

The following summary description sets forth some of the general terms and provisions of our capital stock. Because this is a summary description, it does not contain all of the information that may be important to you. For a more detailed description of our capital stock, you should refer to the applicable provisions of the General Corporation Law of the State of Delaware (the “DGCL”) and our charter and bylaws as in effect at the time of any offering. Copies of our Amended and Restated Certificate of Incorporation, as amended (our “Charter”), and our Eighth Amended and Restated Bylaws (our “Bylaws”) are included as exhibits to the registration statement of which this prospectus forms a part.

Our Authorized Capital Stock

Under our Charter, we are authorized to issue 180,000,000 shares of our common stock, par value $0.001 per share, and 1,000,000 shares of preferred stock, par value $0.001 par value per share. As of August 1, 2022, there were 6,856,574 shares of our Common Stock issued and 6,854,771 outstanding and no shares of our preferred stock issued and outstanding.

Common Stock

Voting Rights. Holders of our Common Stock are entitled to one vote per share. Each of our directors is elected by the affirmative vote of a majority of the votes cast with respect to such director in uncontested elections. In a contested election, each of our directors is elected by an affirmative vote of a plurality of the votes cast by the shares represented and entitled to vote with respect to the election of such director. A “contested election” is defined in our Bylaws as an election with respect to which, as of the record date for the meeting at which directors are to be elected, the number of nominees exceeds the number of directors to be elected at such meeting. Vacancies on the BIOLASE board of directors (our “Board”) may be filled by an affirmative vote of two-thirds of the remaining members of our Board or at a meeting of the stockholders in the manner set forth in the second preceding sentence.

Dividend Rights. Subject to any preferential rights of any outstanding shares of our preferred stock to receive dividends before any dividends may be paid on our Common Stock, the holders of our Common Stock will be entitled to share ratably in any dividends that may be declared by our Board out of funds legally available for the payment of dividends. Our ability to pay dividends on our Common Stock will be limited by restrictions on our ability to pay dividends or make distributions to our stockholders and on the ability of our subsidiaries to pay dividends or make distributions to us, in each case, under the terms of our current, and any future, agreements governing our indebtedness.

Other Rights. Each holder of our Common Stock is subject to, and may be adversely affected by, the rights of the holders of any series of preferred stock that our Board may designate and we may issue in the future. Holders of our Common Stock have no preemptive, conversion or other rights to subscribe for additional shares. Our Common Stock does not carry any redemption rights or any preemptive rights enabling a holder to subscribe for, or receive shares of, any class of our Common Stock or any other securities convertible into shares of any class of our Common Stock.

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Liquidation Rights. Subject to any preferential rights of any outstanding shares of our preferred stock, in the event of our liquidation, dissolution or winding up, holders of our Common Stock are entitled to share ratably in the assets remaining after payment of liabilities and the liquidation preferences of any outstanding preferred stock. Standstill Agreements. Pursuant to (1) a standstill agreement with Jack W. Schuler, Renate Schuler and the Schuler Family Foundation (collectively, the “Schuler Parties”), dated November 10, 2015 (as amended on August 1, 2016 and November 9, 2017, the “Schuler Standstill Agreement”), and (2) a standstill agreement with Larry N. Feinberg, Oracle Partners, L.P., Oracle Institutional Partners, L.P., Oracle Ten Fund Master, L.P., Oracle Associates, LLC and Oracle Investment Management, Inc. (collectively, the “Oracle Parties”) dated November 10, 2015 (as amended on August 1, 2016 and November 9, 2017, the “Oracle Standstill Agreement” and, together with the Schuler Standstill Agreement, the “Standstill Agreements”), each of the Schuler Parties and the Oracle Parties agreed with respect to itself and its associates and affiliates (i) not to purchase or acquire any shares of our Common Stock if such a purchase would result in aggregate beneficial ownership by it and its affiliates and associates in excess of 41% of the issued and outstanding shares of our Common Stock and (ii) not to sell, transfer or otherwise convey shares of our Common Stock (or warrants or other rights to acquire shares of our Common Stock) to anyone who will immediately thereafter beneficially own shares in excess of 20% of the issued and outstanding shares of our Common Stock, as a result of such transfer and other transfers from third parties.

Preferred Stock

Our Charter authorizes our Board to provide for the issuance of up to 1,000,000 shares of preferred stock in one or more series without further authorization from stockholders. Prior to issuance of shares of each series, our Board is required by the DGCL and our Charter to fix the designation, powers, preferences and rights of the shares of such series and the qualifications, limitations or restrictions thereof.

Warrants

Under the Warrants, the selling stockholders have the right to acquire up to an aggregate of 1,405,405 shares of our Common Stock at an exercise price of $4.625 per share. The Warrants are exercisable for a period of five and a half years commencing on June 27, 2022. As of August 1, 2022, 2,820,480 shares of our Common Stock were subject to outstanding warrants to purchase shares of our Common Stock, including the Warrants.

Anti-Takeover Provisions of Delaware Law and Our Governing Documents

Delaware Law

We are subject to Section 203 of the DGCL (“Section 203”). In general, Section 203 prohibits a publicly held Delaware corporation from engaging in “business combination” transactions with any “interested stockholder” for a period of three years following the time that the stockholder became an interested stockholder, unless:

• prior to the time the stockholder became an interested stockholder, either the applicable business combination or the transaction which resulted in the stockholder becoming an interested stockholder is approved by the corporation’s board of directors;

• upon consummation of the transaction which resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding (but not the voting stock owned by the interested stockholder) shares owned by directors who are also officers of the corporation and shares owned by employee stock plans in which the employee participants do not have the right to determine confidentially whether shares held subject to the plan will be tendered in a tender or exchange offer; or

• at or subsequent to the time that the stockholder became an interested stockholder, the business combination is approved by the corporation’s board of directors and authorized at an annual or special meeting of stockholders by the affirmative vote of at least 66 2/3% of the outstanding voting stock which is not owned by the interested stockholder.

A “business combination” is defined to include, in general and subject to exceptions, a merger of the corporation with the interested stockholder; a sale of 10% or more of the market value of the corporation’s consolidated assets to the interested stockholder; certain transactions that result in the issuance of the corporation’s stock to the interested stockholder; a transaction that has the effect of increasing the proportionate share of the corporation’s stock owned by the interested stockholder; and any receipt by the interested stockholder of loans, guarantees or other financial benefits provided by the corporation. An “interested stockholder” is defined to include, in general and subject to exceptions, a person that (1) owns 15% or more of the outstanding voting stock of the corporation or (2) is an “affiliate” or “associate” (as defined in Section 203) of the corporation and was the owner of 15% or more of the corporation’s outstanding voting stock at any time within the prior three year period.

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A Delaware corporation may opt out of Section 203 with an express provision in its original certificate of incorporation or by an amendment to its certificate of incorporation or bylaws expressly electing not to be governed by Section 203 and approved by a majority of its outstanding voting shares. We have not opted out of Section 203. As a result, Section 203 could delay, deter or prevent a merger, change of control or other takeover of our Company that our stockholders might consider to be in their best interests, including transactions that might result in a premium being paid over the market price of our Common Stock and may also limit the price that investors are willing to pay in the future for our Common Stock.

Undesignated Preferred Stock

The ability to authorize undesignated preferred stock makes it possible for our Board to issue one or more series of preferred stock with voting or other rights or preferences. Thus, our Board could authorize the issuance of shares of preferred stock that have priority over our Common Stock with respect to dividends or rights upon liquidation or with terms and conditions that could have the effect of delaying, deferring or preventing a transaction or a change of control of our Company that might involve a premium price for holders of our Common Stock or otherwise be in their best interests.

Requirements for Advance Notification of Stockholder Nominations and Proposals

Our Bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of the Board or a committee of the Board.

Stockholder Action by Written Consent; Special Meetings of Stockholders

Our stockholders may take action by written consent in lieu of a meeting as provided in our Bylaws. Our Bylaws provide that certain procedures, including notifying the Board and awaiting a record date, must be followed for stockholders to act by written consent. A special meeting of our stockholders may be called only by our Board, the Chairman of the Board, the Chief Executive Officer or the President. A special meeting may also be called at the request of stockholders holding a majority of the aggregate number of shares of capital stock of the Company issued and outstanding and entitled to vote at that meeting (subject to certain timeliness and content requirements of the demand).

Amendment of Charter and Bylaws

Our Charter may be amended by the affirmative vote of a majority of the aggregate number of shares of each class of our capital stock issued and outstanding after a resolution of our Board declaring the advisability of such amendment has been adopted in accordance with Delaware law. Our Bylaws may be amended by the affirmative vote of a majority of the aggregate number of shares of each class of our capital stock issued and outstanding (and entitled to vote on the subject matter) present in person or represented by proxy at a meeting of stockholders provided that notice thereof is stated in the written notice of the meeting. Our Bylaws may also be amended by a majority of the Board in accordance with Delaware law and our Charter, except that certain sections of our Bylaws (including but not limited to certain provisions regarding special meetings, voting, officers and approval of securities issuances) require either the affirmative vote of two-thirds of the persons then serving as directors on the Board or our stockholders.

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Forum Selection

Unless the Board acting on behalf of the Company selects an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, another state court located within the State of Delaware or, if no court located within the State of Delaware has jurisdiction, the federal district court for the District of Delaware) shall be the sole and exclusive forum for (i) any derivative action or proceeding brought on behalf of the Company, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers or other employees to the Company or our stockholders, (iii) any action asserting a claim against the Company or any of our directors, officers or other employees arising pursuant to any provision of the DGCL, our Charter or our Bylaws or (iv) any action asserting a claim against the Company or any of our directors, officers or other employees governed by the internal affairs doctrine of the State of Delaware.

Stock Exchange Listing

Our Common Stock trades on The Nasdaq Capital Market under the symbol “BIOL.”

Transfer Agent and Registrar

The transfer agent and registrar for our Common Stock is Computershare Trust Company, N.A.

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SELLING STOCKHOLDERS

This prospectus covers the resale by the selling stockholders identified below of a total of up to 1,405,405 shares of our Common Stock issuable upon the exercise of the Warrants. These Warrants were previously issued June 27, 2022, to the selling stockholders in a private placement.

The information presented in the below table has been calculated based on the assumption that all shares offered hereby will be sold and that no other shares of our Common Stock will be acquired or disposed of by the stockholders named below prior to the termination of this offering. However, we do not know when or in what amounts the selling stockholders may sell or otherwise dispose of the shares covered hereby. The selling stockholders might not sell any or all of the shares covered by this prospectus or may sell or dispose of some or all of the shares other than pursuant to this prospectus. The beneficial ownership set forth below has been determined in accordance with Rule 13d-3 under the Exchange Act. This table has been prepared based on information supplied to us by the selling stockholders, and reflects holdings as of August 12, 2022.

Except as indicated by footnote, and subject to applicable community property laws, we believe that (i) the beneficial owners of the Common Stock listed below have sole voting power and sole investment power with respect to their shares, (ii) none of the selling stockholders are broker-dealers or affiliates of broker-dealers, and (iii) no selling stockholder has any direct or indirect agreement or understanding with any person to distribute his, her or its shares. To the extent any selling stockholder identified below is, or is affiliated with, a broker-dealer, he, she or it could be deemed to be, under SEC Staff interpretations, an “underwriter” within the meaning of the Securities Act.

The following table sets forth information with respect to the beneficial ownership of our Common Stock held, as of August 12, 2022,by the selling stockholders and the number of shares of our Common Stock being offered hereby and information with respect to shares to be beneficially owned by the selling stockholders after completion of this offering. The percentages in the following table reflect the shares beneficially owned by the selling stockholders as a percentage of the total number of shares of our Common Stock outstanding as of August 12, 2022. As of such date, 6,854,771 shares of our Common Stock were outstanding.

	Beneficial Ownership Prior to the Offering					Number of shares offered hereby		Beneficial Ownership After the Offering
	Number of Shares		Percent					Number of Shares		Percent
Selling Stockholders
Armistice Capital Master Fund Ltd.(1)		760,795		9.99	%		1,405,405		760,795		9.99	%

(1) Includes 161,455 shares of our Common Stock currently issuable upon the exercise of warrants held by Armistice Capital Master Fund, Ltd. Does not include 1,970,610 shares of our Common Stock issuable upon exercise of warrants held by Armistice Capital Master Fund, Ltd. that may not currently be issued due to a 4.99% beneficial ownership limitation in certain of the warrants or a 9.99% beneficial ownership limitation in certain of the other warrants. Armistice Capital, LLC (“Armistice”), the investment manager of Armistice Capital Master Fund Ltd., and Steven J. Boyd, the managing member of Armistice hold shared voting and dispositive power over the ordinary shares held by Armistice Capital Master Fund, Ltd. Armistice and Mr. Boyd disclaim beneficial ownership in the shares, except to the extent of his or its pecuniary interest therein. The address for Armistice Capital Master Fund, Ltd., Armistice and Stephen J. Boyd is c/o Armistice Capital, LLC, 510 Madison Avenue, 7th Floor, New York, NY 10022.

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PLAN OF DISTRIBUTION

The selling stockholders and any of their pledgees, assignees and successors-in-interest may, from time to time, sell any or all of the shares of our Common Stock beneficially owned by them and offered hereby directly or through one or more underwriters, broker-dealers or agents. The selling stockholders will be responsible for any underwriting discounts or agent’s commissions. The Common Stock may be sold in one or more transactions at fixed prices, at prevailing market prices at the time of the sale, at varying prices determined at the time of sale, or at negotiated prices.

The selling stockholders may use any one or more of the following methods when selling shares:

• on NASDAQ or any other national securities exchange or quotation service on which the securities may be listed or quoted at the time of sale;

• in the over-the-counter market;

• in transactions otherwise than on these exchanges or systems or in the over-the-counter market;

• through the writing of options, whether such options are listed on an options exchange or otherwise;

• through ordinary brokerage transactions and transactions in which the broker-dealer solicits purchasers;

• through block trades in which the broker-dealer will attempt to sell the shares as agent but may position and resell a portion of the block as principal to facilitate the transaction;

• through purchases by a broker-dealer as principal and resale by the broker-dealer for its account;

• in an exchange distribution in accordance with the rules of the applicable exchange;

• in privately negotiated transactions;

• through the settlement of short sales;

• a combination of any such methods of sale; and

• any other method permitted pursuant to applicable law.

The selling stockholders also may sell shares under Rule 144 promulgated under the Securities Act rather than under this prospectus or any related prospectus supplement.

In connection with the sale of our Common Stock or interests therein, the selling stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of our Common Stock in the course of hedging the positions they assume. The selling stockholders may also sell our Common Stock short and deliver these shares of our Common Stock to close out their short positions, or loan or pledge our Common Stock to broker-dealers that in turn may sell our Common Stock. The selling stockholders may also enter into option or other transactions with broker-dealers or other financial institutions or create one or more derivative securities which require the delivery to such broker-dealer or other financial institution of the shares of our Common Stock covered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction).

The selling stockholders and any broker-dealers or agents that are involved in selling the shares may be deemed to be “underwriters” within the meaning of the Securities Act in connection with such sales. In such event, any compensation received by such broker-dealers or agents and any profit on the resale of the shares purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. While neither we nor any

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selling stockholder can presently estimate the amount of such compensation, in compliance with the guidelines of the Financial Industry Regulatory Authority, Inc. (“FINRA”), the aggregate maximum discount, commission, agency fees or other items constituting underwriting compensation to be received by any FINRA member or independent broker-dealer will not exceed 8% of any offering pursuant to this prospectus and any related prospectus supplement. However, it is anticipated that the maximum commission or discount to be received in any particular offering of securities will be less than this amount.

Because selling stockholders may be deemed to be “underwriters” within the meaning of Section 2(a)(11) of the Securities Act, the selling stockholders will be subject to the prospectus delivery requirements of the Securities Act, which may include delivery through the facilities of NASDAQ pursuant to Rule 153 under the Securities Act. We have agreed to indemnify certain of the selling stockholders against certain liabilities, including liabilities arising under the Securities Act. The selling stockholders may agree to indemnify any agent, dealer or broker-dealer that participates in transactions involving sales of shares of Common Stock against certain liabilities, including liabilities arising under the Securities Act.

The resale securities will be sold only through registered or licensed brokers or dealers if required under applicable state securities laws. In addition, in certain states, the resale securities covered hereby may not be sold unless they have been registered or qualified for sale in the applicable state or an exemption from the registration or qualification requirement is available and is complied with.

Under applicable rules and regulations under the Exchange Act, any person engaged in the distribution of the resale securities may not simultaneously engage in market making activities with respect to the Common Stock for the applicable restricted period, as defined in Regulation M, prior to the commencement of the distribution. In addition, the selling stockholders will be subject to applicable provisions of the Exchange Act and the rules and regulations thereunder, including Regulation M, which may limit the timing of purchases and sales of the Common Stock by the selling stockholders or any other person. We will make copies of this prospectus available to the selling stockholders and have informed them of the need to deliver a copy of this prospectus to each purchaser at or prior to the time of the sale (including by compliance with Rule 172 under the Securities Act).

Each selling stockholder has informed the Company that it does not have any written or oral agreement or understanding, directly or indirectly, with any person to distribute the shares of our Common Stock covered by this prospectus. Upon being notified by a selling stockholder that any material arrangement has been entered into with a broker-dealer or underwriter for the sale of shares of Common Stock through a block trade, special offering, exchange distribution or secondary distribution or a purchase by a broker or dealer, we will file a supplement to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, disclosing (i) the name of each such selling stockholder and of the participating broker-dealer(s) or underwriter(s), (ii) the number of shares of Common Stock involved, (iii) the price at which such shares were or will be sold, (iv) the commissions paid or to be paid or discounts or concessions allowed to such broker-dealer(s) or underwriter(s), where applicable, (v) that, as applicable, such broker-dealer(s) or underwriter(s) did not conduct any investigation to verify the information set out or incorporated by reference in this prospectus and (vi) other facts material to the transaction.

With certain limited exceptions, we have agreed to use commercially reasonable efforts to keep the registration statement of which this prospectus forms a part effective until such time as no selling stockholder owns any warrant or shares of Common Stock issued upon exercise thereof. There can be no assurance that the selling stockholders will sell any or all of the shares of Common Stock registered pursuant to the registration statement, of which this prospectus or any related prospectus supplement forms a part.

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SELECTED FINANCIAL INFORMATION

At the 2022 Annual Meeting, our stockholders approved an amendment to our certificate of incorporation to effect the Reverse Stock Split of our common stock, at a ratio ranging from one-for-two (1:2) to one-for-twenty-five (1:25), with the final ratio to be determined by our Board. Immediately after the 2022 Annual Meeting, our Board approved a one-for-twenty-five (1:25) reverse stock split of the outstanding shares of our common stock. On April 28, 2022, we filed the Amendment to our certificate of incorporation with the Secretary of State of the State of Delaware to effect the Reverse Stock Split, effective as of 11:59 p.m. on April 28, 2022. The Amendment did not change the number of authorized shares of our common stock.

Net loss per share attributable to common stockholders, basic and diluted, has been derived from the audited financial statements of the Company contained in its Annual Report on Form 10-K for the years ended December 31, 2021, 2020 and 2019, except that the net loss per share attributable to common stockholders, basic and diluted, have been revised to reflect the new shares issued based on the reverse stock split ratio discussed above, as shown below.

The historical financial information set forth below may not be indicative of our future performance and should be read together with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our historical financial statements and notes to those statements included in our Annual Report on Form 10-K for the year ended December 31, 2021, and any future filings or other reports we may file with the SEC.

AS REPORTED

	Years Ended December 31,
(in thousands, except per share data)	2021			2020			2019
Net loss attributable to common stockholders	$	(16,704	)	$	(34,207	)	$	(17,855	)
Net loss per share attributable to common stockholders – basic and diluted	$	(0.11	)	$	(0.56	)	$	(0.77	)
Shares used in the calculation of net loss per share – basic and diluted		147,746			61,136			23,201

AS ADJUSTED FOR THE 1:25 REVERSE STOCK SPLIT (UNAUDITED)

	Years Ended December 31,
(in thousands, except per share data)	2021			2020			2019
Net loss attributable to common stockholders	$	(16,704	)	$	(34,207	)	$	(17,855	)
Net loss per share attributable to common stockholders – basic and diluted	$	(2.83	)	$	(13.99	)	$	(19.24	)
Shares used in the calculation of net loss per share – basic and diluted		5,910			2,445			928

LEGAL MATTERS

Sidley Austin LLP will pass upon the validity of the securities being registered by the registration statement of which this prospectus is a part. Michael A. Gordon, a stockholder of the Company, is a partner at such firm. As of the date of this prospectus, Mr. Gordon beneficially owns securities representing less than one percent of the outstanding Common Stock of the Company. Additional legal matters may be passed upon for us, or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements and schedule of BIOLASE, Inc. as of December 31, 2021 and 2020 and for each of the three years in the period ended December 31, 2021 incorporated by reference into this prospectus have been so incorporated in reliance upon the report of BDO USA, LLP, an independent registered accounting firm, incorporated herein by reference, given upon the authority of said firm as experts in accounting and auditing.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference into this prospectus the information contained in other documents we file with the SEC, which means that we can disclose important information to you by referring you to those documents. Any statement contained in any document incorporated or deemed to be incorporated by reference in this prospectus shall be deemed to be modified or superseded, for purposes of this prospectus, to the extent that a statement contained in or omitted from this prospectus, or in any other subsequently filed document that also is or is deemed to be incorporated by reference in this prospectus, modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference the documents listed below which have been filed by us and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) subsequent to the date of the initial filing of the registration statement of which this prospectus forms a part until the offering of the securities covered by this prospectus is completed:

1. Our Annual Report on Form 10-K, for the year ended December 31, 2021, as filed with the SEC on March 17, 2022;

2. Our Quarterly Reports Form 10-Q, for the quarter ended March  31, 2022, as filed with the SEC on May 12, 2022, and for the quarter ended June 30, 2022, as filed with the SEC on August 11, 2022;

3. Our Current Reports on Form 8-K, as filed with the SEC on March 3, 2022, May  2, 2022, May  13, 2022, June  8 2022, June  29, 2022 and July 7, 2022;

4. Our Definitive Proxy Statement on Schedule 14A for our 2022 Annual Meeting of Stockholders, as filed with the SEC on March 30, 2022; and

5. The description of the Common Stock contained in our Registration Statement on Form 8-A, as filed with the SEC on October 30, 1991.

Upon written or oral request, we will provide without charge to each person, including any beneficial owner, to whom a copy of the prospectus is delivered a copy of the documents incorporated by reference in this prospectus (other than exhibits to such documents unless such exhibits are specifically incorporated by reference in this prospectus). You may request a copy of these filings, at no cost, by writing or telephoning us at the following address: BIOLASE, Inc., 27042 Towne Centre Drive, Suite 270, Lake Forest, California 92610, Attention: Investor Relations, telephone: (949) 361-1200.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the informational requirements of the Exchange Act and in accordance therewith file reports, proxy statements and other information with the SEC. Our filings are available to the public over the Internet at the SEC’s website at www.sec.gov, as well as at our website at ir.biolase.com/sec-filings.

Information on any BIOLASE, Inc. website, any subsection, page or other subdivision of any BIOLASE, Inc. website, or any website linked to by content on any BIOLASE, Inc. website, is not part of this prospectus, and you should not rely on that information unless that information is also in this prospectus or incorporated by reference in this prospectus.

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